Scattered Tubular Cells Markers in Macula Densa of Normal Human Adult Kidney

Background: The scattered tubular cells (STCs) are a population of resident progenitor tubular cells with expansion, self-renewal and epithelial differentiation abilities. Although these cells are localized within the proximal (PTs) and distal (DTs) tubules in a normal adult kidney, their presence has never been demonstrated in human macula densa (MD). The purpose of the present study is to describe the presence of STCs in MD using specific markers such as prominin-1 (CD133), cytokeratin 7 (KRT7) and vimentin (VIM). Methods: We analyzed two sets of three consecutive serial sections for each sample. The first sections of each set were immunostained for nNOS to identify MD, the second sections were immune-stained for CD133 (specific STCs marker) while the third sections were analyzed for KRT7 (another STCs specific marker) and VIM (that stains the basal pole of the STCs) in the first and second sets, respectively, in order to study the co-expression of KRT7 and VIM with the CD133 marker. Results: CD133 was localized in some MD cells and in the adjacent DT cells. Moreover, CD133 was detected in the parietal epithelial cells of Bowman’s capsule and in some proximal tubules (PT). KRT7-positive cells were identified in MD and adjacent DT cells, while KRT7 positivity was mostly confined in both DT and collecting ducts (CD) in the other areas of the renal parenchyma. CD133 and KRT7 were co-expressed in some MD and adjacent DT cells. Some of the latter cells were positive both for CD133 and VIM. CD133 was always localized in the apical part of the cells, whereas the VIM expression was evident only in the cellular basal pole. Although some cells of MD expressed VIM or CD133, none of them co-expressed VIM and CD133. Conclusions: The presence of STCs was demonstrated in human adult MD, suggesting that this structure has expansion, self-renewal and epithelial differentiation abilities, similar to all other parts of renal tubules.     

Passive protections against breakdowns between accelerating grids in SPIDER experiment

In the SPIDER experiment a ITER-like full size plasma source will be realized with the target to extract a Dˉ beam of 70 A and then to accelerate it to 100 keV energy. The reduction of the effects due to the frequent breakdowns between the accelerating grids is needed, because of grids damage due to energy deposition by arcing and strong electromagnetic noise (EMI) emission. The solution proposed is a comprehensive design of the circuit. Two passive components are installed: a Damping Resistor and an Output Filter in series to the Power Supplies. Then a doubled screened structure will be adopted for the 30 m long – 100 kV Transmission Line TL, which connects the Ion Source and Acceleration Power Supplies to their loads: the Inner Screen will be connected to the reference ground (the vessel) by a resistive link, the Outer Screen acting as a low-impedance ground. Finally, a Distributed Core Snubber DCS (magnetic snubber) will be installed onto the TL, aimed to increase the damping of the oscillations due to the stray inductances and capacitances. The DCS is composed of 10 magnetic alloy cores and is equipped by a biasing circuit to enhance the flux swing in unsaturated condition during the breakdown. A detailed model of the circuit is developed to evaluate the passive components parameters for protection against breakdown, in which all the magnetic and capacitive couplings between components are modeled as well as the magnetic core snubber saturation.     

Evaluation of beta-lactoglobulin as a stationary phase in high-performance liquid chromatography and as a buffer additive in capillary electrophoresis: observation of a surprising lack of stereoselectivity

Recently, cDNAs encoding brain-specific transmembrane-type protein tyrosine phosphatases (PTPs) with single catalytic domain have been cloned. These include PC12-PTP, PCPTP1, PTPBR7, and PTP-SL, whose cytoplasmic domains had high similarity to STEP, a brain-specific nontransmembrane-type PTP. Based on the high similarity and expression pattern, PCPTP1 seems to be identical with PC12-PTP1 and to be the rat homologue of murine PTPBR7. Here, we report the molecular cloning and expression profile of PCPTP1-Ce, a variant of PCPTP1. Both PCPTP1 mRNA and PCPTP1-Ce mRNA seem to be derived from a single common region gene. Nucleotide and deduced amino acid sequence comparison between PCPTP1-Ce and PCPTP1 revealed that the predicted protein product of PCPTP1-Ce is identical with that translated from the third initiation methionine of the longest ORF of PCPTP1, and that these two clones differ in the 5'-untranslated sequences. Northern blot analyses with specific probes for PCPTP1 and PCPTP1-Ce confirmed our previous observation that PCPTP1-Ce mRNA was almost exclusively expressed in the cerebellum, whereas PCPTP1 was widely expressed in various brain regions dissected including cerebellum. In situ hybridization study demonstrated that PCPTP1-Ce mRNA was exclusively expressed in Purkinje cells of the cerebellum. In contrast, PCPTP1 mRNA was predominantly expressed in granule cells and less in Purkinje cells. Moreover, immunohistochemical analysis using an affinity-purified polyclonal antibody raised against the cytoplasmic region of PCPTP1/PCPTP1-Ce demonstrated that Purkinje cells were strongly immunostained, whereas granule cells were stained only faintly in the cerebellum. These observations clearly demonstrated that PCPTP1-Ce mRNA and its protein products are expressed in Purkinje cells and suggest that PCPTP1-Ce may play an important role in Purkinje cell function in the rat cerebellum.     

Early postoperative nutrition after laparoscopic and open colorectal resection

OBJECTIVE: In the United Kingdom in 1994-95 about 16,500 women aged 50 to 64 were asked to come back earlier than the usual three yearly screening interval for further mammography (early rescreen (ES)) or for a range of further investigations at an assessment centre (early recall (ER)). This study aimed at providing epidemiological data on ES/ER, in particular, how often and why it is used, and what the outcome is of using it. SETTING: National Health Service breast screening programme in the United Kingdom. METHODS: All breast screening units were invited to complete a postal questionnaire. Two reminders were sent. The units were asked retrospectively to provide breast screening data about women aged 50 to 64 from their local computer systems. Women placed on ES/ER were followed up for at least one year. RESULTS: The response rate was 71% (69/97), of which 14% (10/69) were unable to provide the required data, leaving 59 completed questionnaires (61%). The rate of placing women on ES/ER was above 1.0% for 26/54 (48%) responding breast screening units and above 2.0% for 13/54 (24%) units. Women were placed on ES/ER because of (a) previous breast cancer (21% of cases; cancer detection rate 2.4%), (b) diagnostic uncertainty (51%; cancer detection rate 3.0%), or (c) family history (27%; cancer detection rate 0.6%). Breast screening units with a high rate of placing women on ER were significantly more likely to have a high recall rate (rs = 0.63; n = 53; p < 0.0005) or a high benign surgical biopsy rate (rs = 0.33; n = 49; p < 0.05), or both. The cancer detection rate of ES/ER tended to decrease with increasing ES/ER rates (rs = -0.37; n = 51; p < 0.01). CONCLUSIONS: A relatively large number of women were placed on ES or ER for a range of reasons. If the recommendations given are followed, the number of women placed on ER may be reduced while maintaining the cancer detection rate at the required level. The option of ES should not be used.     

Double blind study of the effect of alveolar air distribution influenced by RG 033 in chronic bronchitis

RG 033 is a compound consisting of betametasone in resinic microcapsules which allow a slow and continuous dialysis of the active drug through the membrane in the digestive tract. The drug was studied with regard to its effects on the distribution of alveolar air and its gastric tolerance. In a preliminary study the drug release from the capsules in the pH-conditions of the digestive tract was studied by means of a physico-chemical model. Two groups of 15 patients with broncho-obstruction reversed by salbutamol, a potent beta 2-sympathomimetic, were included in the trial. One group received 1 mg and the other 2 mg of the drug. An alternate scheme was used for the treatments. The functional methods used to assess the ventilatory results were chosen according to the conclusions of a previous comprehensive study by one of the authors [7] [8]. The ventilatory results of both dosages were quite similar. This observation suggests that a maximum effect on alveolar air distribution was obtained with 1 mg. No unfavourable side-effect on the gastric mucosa was observed.     

Social information use and the evolution of unresponsiveness in collective systems

Animal groups in nature often display an enhanced collective information-processing capacity. It has been speculated that natural selection will tune this response to be optimal, ensuring that the group is reactive while also being robust to noise. Here, we show that this is unlikely to be the case. By using a simple model of decision-making in a dynamic environment, we find that when individuals behave rationally and are subject to selection based on their accuracy, optimality of collective decision-making is not attained. Instead, individuals overly rely on social information and evolve to be too readily influenced by their neighbours. This is due to a classic evolutionary conflict between individual and collective interest. The result is a sub-optimal system that is poised on the cusp of total unresponsiveness. Individuals in the evolved group exhibit delayed reactions to changes in the environment, before responding with rapid, socially reinforced transitions, reminiscent of familiar human and animal social systems (markets, stampedes, fashions, etc.). Our results demonstrate that behaviour of this type may not be pathological, but instead could represent an evolutionary attractor for such collective systems.     

Structural rearrangement at the yttrium-depleted surface of HCl-processed yttrium aluminosilicate glass for Y-microsphere brachytherapy

The design of a process to create yttrium aluminosilicate microspheres with a core–shell structure is of interest in the field of cancer brachytherapy. Glass microspheres with yttrium-depleted shell may indeed reduce the risk of ⁹⁰Y release into the organism. Here we show – by means of confocal micro-Raman scattering, microfluorescence, X-ray-fluorescence analysis, and IR spectroscopy – that yttrium depletion may be achieved by etching in HCl solution (pH 2) at a rate of 1 μm day⁻¹ in bulk glass and 3 μm day⁻¹ in glass microsphere (35 μm of diameter). Importantly, the spectroscopic results – collected in confocal configuration along the processed layer – indicate a high degree of structural reconstruction of the glass network, with the formation of an interconnected silicate-rich glass that surrounds a core of unmodified yttrium aluminosilicate. We also demonstrate that the process is driven by non-bridging oxygen sites, which regulate the hydroxylation and structural reconstruction of the glass within the Y-depleted layer. The analysis gives also some insight into open fundamental questions about the short-range structure and the chemical stability of this kind of glass, which is also important in photonics and nuclear waste disposal.     

Study of large gap 200 kV breakdowns in vacuum with high stored energy for ITER neutral beam accelerator

In the context of the ITER contract “ITER/CT/07/219–200 kV Stored Energy Tests”, electrical breakdown tests have been performed in vacuum with a stored energy of up to 425 J. The experiments have been conceived and performed with the collaboration of Consorzio RFX. The tests are being performed in the 1 MV test facility at IRFM, CEA-Cadarache. They should simulate the conditions that will be found in the ITER Neutral Beam accelerator, at 200 kV. This paper presents the set-up of the test bed, the choice of critical components, the diagnostic equipments and the results obtained with 200 kV applied on the anode electrode.