Ceramic foam plates: a new tool for processing fresh radical prostatectomy specimens

Procurement of fresh tissue of prostate cancer is critical for biobanking and generation of xenograft models as an important preclinical step towards new therapeutic strategies in advanced prostate cancer. However, handling of fresh radical prostatectomy specimens has been notoriously challenging given the distinctive physical properties of prostate tissue and the difficulty to identify cancer foci on gross examination. Here, we have developed a novel approach using ceramic foam plates for processing freshly cut whole mount sections from radical prostatectomy specimens without compromising further diagnostic assessment. Forty-nine radical prostatectomy specimens were processed and sectioned from the apex to the base in whole mount slices. Putative carcinoma foci were morphologically verified by frozen section analysis. The fresh whole mount slices were then laid between two ceramic foam plates and fixed overnight. To test tissue preservation after this procedure, formalin-fixed and paraffin-embedded whole mount sections were stained with hematoxylin and eosin (H&E) and analyzed by immunohistochemistry, fluorescence, and silver in situ hybridization (FISH and SISH, respectively). There were no morphological artifacts on H&E stained whole mount sections from slices that had been fixed between two plates of ceramic foam, and the histological architecture was fully retained. The quality of immunohistochemistry, FISH, and SISH was excellent. Fixing whole mount tissue slices between ceramic foam plates after frozen section examination is an excellent method for processing fresh radical prostatectomy specimens, allowing for a precise identification and collection of fresh tumor tissue without compromising further diagnostic analysis.

Heavy Metals in Crop Plants: Transport and Redistribution Processes on the Whole Plant Level

Copper, zinc, manganese, iron, nickel and molybdenum are essential micronutrients for plants. However, when present in excess they may damage the plant or decrease the quality of harvested plant products. Some other heavy metals such as cadmium, lead or mercury are not needed by plants and represent pollutants. The uptake into the roots, the loading into the xylem, the acropetal transport to the shoot with the transpiration stream and the further redistribution in the phloem are crucial for the distribution in aerial plant parts. This review is focused on long-distance transport of heavy metals via xylem and phloem and on interactions between the two transport systems. Phloem transport is the basis for the redistribution within the shoot and for the accumulation in fruits and seeds. Solutes may be transferred from the xylem to the phloem (e.g., in the small bundles in stems of cereals, in minor leaf veins). Nickel is highly phloem-mobile and directed to expanding plant parts. Zinc and to a lesser degree also cadmium are also mobile in the phloem and accumulate in meristems (root tips, shoot apex, axillary buds). Iron and manganese are characterized by poor phloem mobility and are retained in older leaves.

Phyllotaxis — a new chapter in an old tale about beauty and magic numbers

Phyllotaxis, the regular arrangement of leaves and flowers around the stem, is one of the most fascinating patterning phenomena in biology. Numerous theoretical models, that are based on biochemical, biophysical and other principles, have been proposed to explain the development of the patterns. Recently, auxin has been identified as the inducer of organ formation. An emerging model for phyllotaxis states that polar auxin transport in the plant apex generates local peaks in auxin concentration that determine the site of organ formation and thereby the different phyllotactic patterns found in nature. The PIN proteins play a primary role in auxin transport. These proteins are localized in a polar fashion, reflecting the directionality of polar auxin transport. Recent evidence shows that most aspects of phyllotaxis can be explained by the expression pattern and the dynamic subcellular localization of PIN1.

Numerical study of the laser-tip coupling in surface plasmon assisted stacked-double-gate field emitter arrays

Recently, sub-wavelength-pitch stacked double-gate metal nanotip arrays have been proposed to realize high current, high brightness electron bunches for ultrabright cathodes for x-ray free-electron laser applications. With the proposed device structure, ultrafast field emission of photoexcited electrons is efficiently driven by vertical incident near infrared laser pulses, via near field coupling of the surface plasmon polariton resonance of the gate electrodes with the nanotip apex. In this work, in order to gain insight in the underlying physical processes, the authors report detailed numerical studies of the proposed device. The results indicate the importance of the interaction of the double-layer surface plasmon polariton, the position of the nanotip, as well as the incident angle of the near infrared laser pulses.

A retrospective analysis of factors influencing the success of autotransplanted posterior teeth

BACKGROUND Survival and success rates of tooth transplantations even after long follow-up periods have been shown to be very high. Nevertheless, it is important to analyse factors potentially influencing these rates. The aim of this study was to assess the influence on success of potential factors. METHODS The research was based on a retrospective analysis of clinical and radiological data from a sample of 59 subjects (75 transplanted teeth). The follow-up period varied from 0.44 to 12.28 years (mean 3.95 years). Success rates were calculated and depicted with Kaplan-Meier plots. Log-rank tests were used to analyse the effect of root development stage, apex width, the use of enamel matrix proteins or the surgeon on success of transplantations. RESULTS Results for success of premolar transplantations were comparable with already published data, while molars performed worse than shown in other studies. The surgeon performing the transplantation (p = 0.001) and tooth type (p ≤ 0.001) were significantly associated with transplantation success. Use of enamel matrix proteins (p = 0.10), root development stage (p = 0.13), the recipient area (p = 0.48) and apex width (p = 0.59) were not significantly associated with success. CONCLUSIONS Molar transplantations were not as successful as premolar transplantations; however, success rates varied greatly depending on the surgeon's experience. The use of enamel matrix proteins as well as root development stage, the recipient area and apex width did not show significant associations with success of tooth transplantations.

A Specific Mapping Study Using Fluorescence Sentinel Lymph Node Detection in Patients with Intermediate- and High-risk Prostate Cancer Undergoing Extended Pelvic Lymph Node Dissection.

Sentinel lymph node (SLN) detection techniques have the potential to change the standard of surgical care for patients with prostate cancer. We performed a lymphatic mapping study and determined the value of fluorescence SLN detection with indocyanine green (ICG) for the detection of lymph node metastases in intermediate- and high-risk patients undergoing radical prostatectomy and extended pelvic lymph node dissection. A total of 42 patients received systematic or specific ICG injections into the prostate base, the midportion, the apex, the left lobe, or the right lobe. We found (1) that external and internal iliac regions encompass the majority of SLNs, (2) that common iliac regions contain up to 22% of all SLNs, (3) that a prostatic lobe can drain into the contralateral group of pelvic lymph nodes, and (4) that the fossa of Marcille also receives significant drainage. Among the 12 patients who received systematic ICG injections, 5 (42%) had a total of 29 lymph node metastases. Of these, 16 nodes were ICG positive, yielding 55% sensitivity. The complex drainage pattern of the prostate and the low sensitivity of ICG for the detection of lymph node metastases reported in our study highlight the difficulties related to the implementation of SNL techniques in prostate cancer. PATIENT SUMMARY There is controversy about how extensive lymph node dissection (LND) should be during prostatectomy. We investigated the lymphatic drainage of the prostate and whether sentinel node fluorescence techniques would be useful to detect node metastases. We found that the drainage pattern is complex and that the sentinel node technique is not able to replace extended pelvic LND.

Auxin Regulates the Initiation and Radial Position of Plant Lateral Organs

Leaves originate from the shoot apical meristem, a small mound of undifferentiated tissue at the tip of the stem. Leaf formation begins with the selection of a group of founder cells in the so-called peripheral zone at the flank of the meristem, followed by the initiation of local growth and finally morphogenesis of the resulting bulge into a differentiated leaf. Whereas the mechanisms controlling the switch between meristem propagation and leaf initiation are being identified by genetic and molecular analyses, the radial positioning of leaves, known as phyllotaxis, remains poorly understood. Hormones, especially auxin and gibberellin, are known to influence phyllotaxis, but their specific role in the determination of organ position is not clear. We show that inhibition of polar auxin transport blocks leaf formation at the vegetative tomato meristem, resulting in pinlike naked stems with an intact meristem at the tip. Microapplication of the natural auxin indole-3-acetic acid (IAA) to the apex of such pins restores leaf formation. Similarly, exogenous IAA induces flower formation on Arabidopsis pin-formed1-1 inflorescence apices, which are blocked in flower formation because of a mutation in a putative auxin transport protein. Our results show that auxin is required for and sufficient to induce organogenesis both in the vegetative tomato meristem and in the Arabidopsis inflorescence meristem. In this study, organogenesis always strictly coincided with the site of IAA application in the radial dimension, whereas in the apical–basal dimension, organ formation always occurred at a fixed distance from the summit of the meristem. We propose that auxin determines the radial position and the size of lateral organs but not the apical–basal position or the identity of the induced structures.

Function of histaminergic retinopetal axons in rat and primate retinas

Mammalian retinas receive input from histaminergic neurons in the posterior hypothalamus. These neurons are most active during the waking state of the animal, but their role in retinal information processing is not known. To determine the function of these retinopetal axons, their targets in the rat and monkey retina were identified. Using antibodies to three histamine receptors, HR1, HR2, and HR3, the immunolabeling was analyzed by confocal and electron microscopy. These experiments showed that mammalian retinas possess histamine receptors. In macaques and baboons, diurnal species, HR3 receptors were found at the apex of ON-bipolar cell dendrites in cone pedicles and rod spherules, sclerad to the other neurotransmitter receptors that have been localized there. In addition, HR1 histamine receptors were localized to large puncta in the inner plexiform layer, a subset of ganglion cells and retinal blood vessels. In rats, a nocturnal species, the localization of histamine receptors in the retina was markedly different. Most HR1 receptors were localized to dopaminergic amacrine cells and on elements in the rod spherule. To determine how histaminergic retinopetal axons contribute to retinal information processing, responses of retinal ganglion cells to histamine were analyzed. The effects of histamine on the maintained and light-evoked activity of retinal ganglion cells were analyzed. In monkeys, histamine and the HR3 agonist, methylhistamine, increased or decreased the maintained activity of most ganglion cells, but a few did not respond. The responses of a subset of ganglion cells to light stimuli were decreased by histamine, a finding suggesting that histaminergic retinopetal axons contribute to light adaptation during the day. In rats, histamine nearly always increased the maintained activity and produced both increases and decreases in the light responses. The effects of histamine on maintained activity of ganglion cells in the rat can be partially attributed to HR1-mediated changes in the activity of dopaminergic amacrine cells, at night. Together, these experiments provide the first indication of the function of retinopetal axons in mammalian retinas. ^

Morfología y anatomía floral de Schinopsis balansae (Anacardiaceae)

Se realizó el análisis morfo-anatómico de Schinopsis balansae Engl. con microscopía óptica y electrónica de barrido a fin de obtener datos de las flores de esta especie, definida como polígamo-dioica. Los resultados muestran que las flores estructuralmente perfectas son funcionalmente pistiladas, si bien presentan cinco estaminodios, los mismos carecen de tejido esporógeno; mientras que en las flores estaminadas la estructura denominada pistilo vestigial no es más que la excrecencia del ápice del receptáculo, cubierta por tejido nectarífero. De este modo, lo correcto es describir S. balansae como especie dioica. El estudio de la vascularización de las flores estaminadas muestra que el proceso de reducción es completo, ya que ni siquiera persisten los haces vasculares del pistilo. El gineceo de las flores pistiladas es pseudomonómero, con un carpelo funcional, un estilo/estigma dorsal y un óvulo; además posee dos carpelos vestigiales representados por sendos estilo/estigma laterales. Ambos tipos de flores presentan un disco nectarífero intraestaminal, con nectarostomatas para la salida del néctar. El análisis de la estructura anatómica de S. balansae brinda datos que concuerdan con los encontrados en otros géneros estudiados de la subfamila Anacardioideae de la familia Anacardiaceae.