Calibration of scintillation-light filters for neutron time-of-flight spectrometers at the National Ignition Facility.

Sixty-four neutral density filters constructed of metal plates with 88 apertures of varying diameter have been radiographed with a soft x-ray source and CCD camera at National Security Technologies, Livermore. An analysis of the radiographs fits the radial dependence of the apertures' image intensities to sigmoid functions, which can describe the rapidly decreasing intensity towards the apertures' edges. The fitted image intensities determine the relative attenuation value of each filter. Absolute attenuation values of several imaged filters, measured in situ during calibration experiments, normalize the relative quantities which are now used in analyses of neutron spectrometer data at the National Ignition Facility.

A multi-wavelength, high-contrast contact radiography system for the study of low-density aerogel foams.

A multi-wavelength, high contrast contact radiography system has been developed to characterize density variations in ultra-low density aerogel foams. These foams are used to generate a ramped pressure drive in materials strength experiments at the National Ignition Facility and require precision characterization in order to reduce errors in measurements. The system was used to characterize density variations in carbon and silicon based aerogels to ∼10.3% accuracy with ∼30 µm spatial resolution. The system description, performance, and measurement results collected using a 17.8 mg/cc carbon based JX-6 (C20H30) aerogel are discussed in this manuscript.

Helicobacteriose em leitões: imuno-histoquímica em amostras colhidas por meio de gastroscopia / Helicobacter infection in piglets: Immunohistochemical analysis in mucosal samples collected using gastroscopy

O diagnóstico da úlcera gastroesofágica (UGE) é fundamental para que se tente a recuperação dos afetados, entretanto há grande dificuldade na sua realização de forma precisa. Modernos endoscópios são ferramentas importantes nesse sentido e podem ser usados para determinar em que fase da criação a ulceração ocorre. A bactéria Helicobacter tem sido associada à UGE e gerado perdas econômicas. Tendo em vista que poucos trabalhos têm sido realizados para identificação do problema precocemente, este estudo teve como objetivo detectar as lesões relacionando-as, ou não, com a bactéria Helicobacter spp., mediante análises macroscópica e histopatológica de amostras colhidas por meio da gastroscopia. Foram utilizados 20 animais de ambos os sexos, pesando entre 22 e 26kg e com 65 dias de idade. O aparelho utilizado foi um gastrovideoscópio da marca Karl Storz, modelo 1380NKS. Foram colhidas amostras das regiões anatômicas aglandular (quadrilátero esofágico) e glandular (cárdica, fúndica e pilórica) para o teste ultrarrápido da urease e para as avaliações histopatológicas e imuno-histoquímicas. Onze animais apresentaram lesões na região aglandular à endoscopia, e microscopicamente 15 animais apresentaram paraqueratose. Em 18 animais, foram observadas alterações em pelo menos uma das três regiões glandulares. As lesões foram maiores na região cárdica, seguida da antral e da fúndica. Em relação ao teste ultrarrápido da urease, sete animais foram negativos nas quatro regiões, e 13 positivos em pelo menos uma delas. Em relação à imuno-histoquímica (IHQ), 10 animais foram negativos em todas as regiões e 10 foram positivos em pelo menos uma delas. Os achados pré-ulcerativos não demonstraram relação com o Helicobacter spp., que apresenta caráter saprofítico e oportunista confirmado pela sua imunomarcação em áreas sem lesão...

Gastroesophageal ulcer (GEU) diagnosis is fundamental for the treatment and recovery of the affected animal stock. GEU is a condition affecting animals, resulting in depletion of animal stock and subsequent economic losses. Helicobacter spp. have been associated with GEU. Modern endoscopes are important for detecting the stage of the breeding process at which the ulceration occurs. However, few studies regarding early detection of GEU have been conducted. Therefore, we aimed to identify whether GEU lesions were related to Helicobacter spp. infection, using gastroscopy as a diagnostic technique for macroscopic and histopathological analyses. Twenty piglets (both male and female) with a mean age of 65 days were included (weight, 22-26 kg). We used a Karl Storz Gastrovideoscope (model 1380NKS). Samples from nonglandular and glandular (cardia, fundus, and pylorus) regions were collected for the ultra-rapid urease test and for histopathological and immunohistochemical (IHC) evaluations. Eleven animals showed macroscopic lesions in the nonglandular region during endoscopy, and 15 animals showed parakeratosis on histological analysis. Lesions in at least 1 glandular region were observed in 18 animals. The lesions were bigger in the cardiac region, followed by those in the antrum and the fundus. Regarding the ultra-rapid urease test, 7 animals were negative in all 4 regions and 13 were positive in at least 1 region. On IHC, 10 animals were negative in all 4 regions and 10 were positive in at least 1 region. However, pre-ulcerative findings were not correlated with Helicobacter spp. infection in the present study. The positive IHC findings for Helicobacter spp in regions without ulcerative lesions suggest its saprophytic and opportunistic nature...

Hedgehog Signaling Pathway Database: a repository of current annotation efforts and resources for the Hh research community.

The Hedgehog Signaling Pathway Database is a curated repository of information pertaining to the Hedgehog developmental pathway. It was designed to provide centralized access to a wide range of relevant information in an organism-agnostic manner. Data are provided for all genes and gene targets known to be involved in the Hh pathway across various organisms. The data provided include DNA and protein sequences as well as domain structure motifs. All known human diseases associated with the Hh pathway are indexed including experimental data on therapeutic agents and their molecular targets. Hh researchers will find useful information on relevant protocols, tissue cell lines and reagents used in current Hh research projects. Curated content is also provided for publications, grants and patents relating to the Hh pathway. The database can be accessed at http://www.hedgehog.sfsu.edu.

Radiation-driven hydrodynamics of high- hohlraums on the national ignition facility.

The first hohlraum experiments on the National Ignition Facility (NIF) using the initial four laser beams tested radiation temperature limits imposed by plasma filling. For a variety of hohlraum sizes and pulse lengths, the measured x-ray flux shows signatures of filling that coincide with hard x-ray emission from plasma streaming out of the hohlraum. These observations agree with hydrodynamic simulations and with an analytical model that includes hydrodynamic and coronal radiative losses. The modeling predicts radiation temperature limits with full NIF (1.8 MJ), greater, and of longer duration than required for ignition hohlraums.

Measurement of the absolute hohlraum-wall albedo under ignition foot drive conditions.

We present measurements of the absolute albedos of hohlraums made from gold or from high-Z mixtures. The measurements are performed over the range of radiation temperatures (70-100 eV) expected during the foot of an indirect-drive temporally shaped ignition laser pulse, where accurate knowledge of the wall albedo (i.e., soft x-ray wall reemission) is most critical for determining capsule radiation symmetry. We find that the gold albedo agrees well with calculations using the supertransition array opacity model, potentially providing additional margin for inertial confinement fusion ignition.

Avaliação de lesões gástricas induzidas por antiinflamatóriosa não esteróides (AINEs) através da gastroscopia em cães (Canis familiaris) / Evalution of gastric lesions caused by nonsteroidal anti-inflammatory (NSAIDs) in dogs (Canis familiaris)7

Os AINEs são drogas amplamente utilizadas para o alívio da dor de origem musculoesquelética e em procedimentos cirúrgicos, principalmente ortopédicos,, no pré, trans e pós-operatório. Os efeitos colaterais dos AINEs resultam de sua ação inibitória sobre a cicloxigenase, destacando sua atuação sobre o aparelho digestório, tornando o exame gastroscópico de grande valia para uma avaliação intraluminal direta. Foram utilizados seis cães, sendo um mantido como controle, sem raça definida, três machos e três fêmeas e idades variadas onde se dividiu o experimento em três módulos: Módulo 1: flunixim meglumine na dosagem de 1,0 mg/kg a cada 24 horas por 5 dias; Módulo 2: piroxican na dosagem de 0,3 mg/kg a cada 48 horas, perfazendo um total de 3 aplicações; e, Módulo 3: cetoprofeno na dosagem de 1,0 mg/kg com intervalo de 24 horas durante 5 dias. Os pacientes foram submetidos a exame endoscópico no 1º, 4º, 6º, 8º, 10º dia. Nas três drogas testadas foram observadas lesões gástricas que variaram de gastrite leve até ulceração, sendo o piroxican o que demonstrou maior potencial ulcerogênico. Clinicamente não foi observada qualquer alteração. O exame endoscópico se mostrou eficaz, preciso e com grande acuidade para o diagnóstico das alterações gástricas provocadas pelas drogas testadas.

Signaling reaches to new dimensions in Drosophila imaginal discs.

Finding that peripodial cells in wing and eye imaginal discs are essential for the growth and patterning of the separate layer of disc cells now opens the study of interacting cell layers to the powerful developmental genetic techniques with which the Drosophila system is blessed. We can anticipate that future work will identify how such interactions contribute to patterning and how the mechanisms and processes that are involved are conserved in vertebrates. We can also look forward to contributions that this work will make to understand-ing the role of interconnecting cell extensions in such signaling processes. In this minireview, we have noted numerous types of signaling cells in which cellular extensions have been observed. At present, neither the functional nor structural relationship of these related structures is known. It is certainly tempting to suggest that these structures are conduits for signals or that they function as sensors. There is, as yet, no direct experimental evidence for such roles.

Hedgehog signal transduction in the posterior compartment of the Drosophila wing imaginal disc.

Drosophila Hedgehog (Hh) is secreted by Posterior (P) compartment cells and induces Anterior (A) cells to create a developmental organizer at the AP compartment border. Hh signaling converts Fused (Fu) to a hyperphosphorylated form, Fu*. We show that A border cells of wing imaginal discs contain Fu*. Unexpectedly, P cells also produce Fu*, in a Hh-dependent and Ptc-independent manner. Increasing Ptc, the putative Hh receptor expressed specifically by A cells, reduced Fu*. These results are consistent with proposals that Ptc downregulates Hh signaling and suggest that a receptor other than Ptc mediates Hh signaling in P cells of imaginal discs. We conclude that Hh signals in these P cells and that the outputs of the pathway are blocked by transcriptional repression.

GFP-tagged balancer chromosomes for Drosophila melanogaster.

We constructed green fluorescent protein (GFP)-expressing balancer chromosomes for each of the three major chromosomes of Drosophila melanogaster. Expression of GFP in these chromosomes is driven indirectly by a Kruppel (Kr) promoter, via the yeast GAL4-UAS regulatory system. GFP fluorescence can be seen in embryos as early as the germ band extension stage, and can also be seen in larvae, pupae, and adults. We show the patterns of GFP expression of these balancers and demonstrate the use of the balancers to identify homozygous progeny.

Cytonemes: cellular processes that project to the principal signaling center in Drosophila imaginal discs.

Wing imaginal disc cells in Drosophila develop by using information received from a signaling center associated with the anterior/posterior compartment border. We show here that disc cells have thin, actin-based extensions (cytonemes) that project to this signaling center. Cytonemes can be induced when cells from the lateral flanks of a wing disc are cultured next to cells from the A/P border or next to a source of fibroblast growth factor. Mouse limb bud cells also grow projections during a brief culture period, indicating that cytonemes are an attribute of both vertebrate and invertebrate cells. We suggest that cytonemes may be responsible for some forms of long-range cell-cell communication.

Gangliogenesis in leech: morphogenetic processes leading to segmentation in the central nervous system.

Using intracellular lineage tracers to study the main neurogenic lineage (N lineage) of the glossiphoniid leech embryo, we have characterized events leading from continuous columns of segmental founder cells (nf and ns primary blast cells) to discrete, segmentally iterated ganglia. The separation between prospective ganglia was first evident as a fissure between the posterior boundary of nf- and the anterior boundary of ns-derived progeny. We also identified the sublineages of nf-derived cells that contribute parallel stripes of cells to each segment. These stripes of cells project ventrolaterally from the dorsolateral margin of each nascent ganglion to the ventral body wall. The position and orientation of the stripes suggests that they play a role in forming the posterior segmental nerve; they are not coincident with the ganglionic boundary, and they form well after the separation of ganglionic primordia. Previous work has shown that cells in the anterior stripe express the leech engrailed-class gene. Thus, in contrast to the role of cells expressing engrailed in Drosophila, the stripes of N-derived cells expressing an engrailed-class gene in leech do not seem to play a direct role in segmentation or segment polarity.

Proteolysis that is inhibited by hedgehog targets Cubitus interruptus protein to the nucleus and converts it to a repressor.

Cell-cell communication at anterior/posterior compartment borders in Drosophila involves Hedgehog (Hh), a protein secreted by posterior cells, and Cubitus interruptus (Ci), a protein in the Hh response pathway in anterior cells. Although Ci is thought to have roles as a transcription factor repressing hh expression and activating target genes, it localizes in the cytoplasm of anterior cells. We report here the identification of a domain that tethers Ci in the cytoplasm and show that in some anterior cells, Ci is cleaved to generate a form that lacks the tethering domain. This form translocates to the nucleus where it represses hh and other target genes. Hh inhibits proteolysis of Ci, and we suggest that this inhibition leads to the observed patterns of expression of key target genes at the compartment border.

Long-term results of revision total hip arthroplasty.

A total of 138 revision hip arthroplasties in 134 patients, all operated upon by one surgeon, were followed for an average of 7.4 years. The overall results were reasonable, with good to excellent Mayo hip scores in 62% and little or no pain in 86%. These results were independent of body weight, age, primary diagnosis and type of arthroplasty used. The incidence of radiological loosening was alarming, though comparable to that found in other series. Our findings indicate that it may be wise to replace both components even when, after careful assessment before and during operation, one of them seems to be securely fixed.

Revision of infected total hip arthroplasty.

Extension of infection down the medulla of the femur to the supracondylar region may occur in cases of chronic infected total hip arthroplasty. Because this cannot always be identified before operation, the femur should be reamed and flushed proximally from the lateral condyle in all cases where there is suspicion of infection around the femoral component. Where infection is unequivocal and extensive, a period of irrigation and suction drainage is advisable before final total hip arthroplasty. After the prosthesis has been inserted in either one or two stages, it is wise not to rely on antibiotic cement mixtures alone but to monitor the bacterial flora and prescribe local antibiotic therapy accordingly.

A radiological study of fractures of acrylic cement in relation to the stem of a femoral head prosthesis.

The incidence and prognostic significance of fractures of acrylic cement related to the stem of a femoral head prosthesis in total hip replacement are examined. These fractures are demonstrated when the cement has been rendered radio-opaque by the addition of barium sulphate. One and a half percent of the radiographs of 6,649 patients showed these fractures, which were sometimes associated with subsidence of the prosthesis. Fracture of the cement was usually evident at the six-month post-operative review, if it occurred at all. This radiological complication was devoid of symptoms in the majority of cases and tended to occur in patients with excellent functional recovery. In a minority of patients pain in the thigh during the first six months seemed likely to be explained by this fracture. Slight subsidence of the prosthesis in the cement bed appeared to result in a new and final position of stability. The prognosis was very good; only when separation of the fracture exceeded about 4 millimetres was the prognosis doubtful, in which case a chronic deep infection might be suspected. Possible mechanical and structural causes of fracture of the cement are discussed.

Radiological assessment of the Charnley total hip arthroplasty.

A description is given of the normal radiological appearances of the Charnley total hip arthroplasty. This is followed by a description of the radiological assessment of the complications that may be associated with this operation.