Secondary Nodules Research Articles

Thermal Analysis of the Formation of Chunky Graphite during Solidification of Heavy-section Spheroidal Graphite Iron Parts

Analysis of cooling curves recorded at the centre of large blocks cast with near-eutectic spheroidal graphite cast irons prone to give chunky graphite has been checked against microstructure observations. It has been observed that solidification proceeds totally at temperatures lower than the stable eutectic temperature and the following solidification sequence could be proposed: 1) nucleation of primary graphite in the liquid; 2) initial eutectic reaction processing by growth of austenite-like dendrites encapsulating the primary nodules; 3) bulk eutectic reaction related to nucleation and then growth of CHG cells and of secondary nodules, these latter giving spheroidal graphite eutectic cells. It was found that the maximum recalescence during the eutectic reaction first increases with the volume of the block affected by chunky graphite, and then decreases when most of the material is affected. Interestingly enough, a relationship between the volume of the blocks affected by CHG and the recalescence measured on TA cups has been observed.

Self-organization of Copper Secondary Nodules by the Second Micro-MHD Effect

In copper electrodeposition under a magnetic field parallel to an electrode surface, at the initial stage, 3D nucleation is suppressed, yielding a flat surface (the first micro-MHD effect). However, after long-term deposition with proton adsorption, characteristic secondary nodules emerge from 2D nucleation, which is called the second micro-MHD effect. From the instability analysis of non-equilibrium fluctuations, at the initial stage, the 2D nuclei are self-organized at a negative overpotential of the double layer, whereas for the secondary nodule formation, a positive overpotential of the double layer is required. Therefore, it is concluded that the adsorption of proton changes the polarity of the double layer overpotential from negative to positive, the secondary nodules are self-organized.

Quantification of Lumpy Skin Disease Virus Following Experimental Infection in Cattle

Lumpy skin disease along with sheep pox and goatpox are the most serious poxvirus diseases of livestock, and are caused by viruses that belong to the genus Capripoxvirus within the subfamily Chordopoxvirinae, family Poxviridae. To facilitate the study of lumpy skin disease pathogenesis, we inoculated eight 4- to 6-month-old Holstein calves intravenously with lumpy skin disease virus (LSDV) and collected samples over a period of 42 days for analysis by virus isolation, real-time PCR and light microscopy. Following inoculation, cattle developed fever and skin nodules, with the extent of infection varying between animals. Skin nodules remained visible until the end of the experiment on day post-inoculation (DPI) 42. Viremia measured by real-time PCR and virus isolation was not observed in all animals but was detectable between 6 and 15 DPI. Low levels of viral shedding were observed in oral and nasal secretions between 12 and 18 DPI. Several tissues were assessed for the presence of virus at DPI 3, 6, 9, 12, 15, 18 and 42 by virus isolation and real-time PCR. Virus was consistently detected by real-time PCR and virus isolation at high levels in skin nodules indicating LSDV has a tropism for skin. In contrast, relatively few lesions were observed systemically. Viral DNA was detected by real-time PCR in skin lesions collected on DPI 42. Cattle developing anti-capripoxvirus antibodies starting at DPI 21 was detected by serum neutralization. The disease in this study varied from mild with few secondary skin nodules to generalized infection of varying severity, and was characterized by morbidity with no mortality.

Self-organization of Copper Secondary Nodules by Second Micro-MHD Effect

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Un syndrome paranéoplasique rare: la thrombose veineuse cérébrale

Cerebral venous thromboses are uncommon in cancer, and rarely presents as a paraneoplastic syndrome. A 42-year-old patient presented with headache and a bilateral papillar edema. Cerebral computed tomographic (CT) scan did not find a tumoral process. Biological tests disclosed increased acute phase reactants and liver cytolysis and cholestasis. Cerebral magnetic resonance angiogram showed superior longitudinal venous thrombosis. Thoracoabdominal CT scan was performed and disclosed multiple secondary liver nodules. CA 19-9 serum level was increased to 7648 UI/ml. Liver biopsy revealed a slightly differentiated mucinous adenocarcinoma compatible with a biliary tract or a pancreatic neoplasia. Chemotherapy with cisplatin and 5-fluorouracil was instituted but disease outcome was rapidly unfavourable.

THE INFLUENCE OF SYNTHETIC POLYSACCHARIDE ON BOTH EFFICIENCY OF SYMBIOSIS AND PEROXIDASE AND CATALASE ACTIVENESS OF PEA AND SOYA BEANS

The influence of synthetic polysaccharide MOD-19 on the effic¬iency of nitrogen fixation ofpea and soya plants as well as on ferment activity of the antioxidative defense system - peroxidase and catalase was investigated. It has been shown that the metabolic process intensifying is ob¬served in pea and soya plants grown from the seeds, wich had been tilled before sowing by nodule bacterium (pea - Rhizobium leguminosarum bv. viciae 263b and soya beans - Bradyrhizobium japonicum 634b) and by nonspecific for these bean cultures polysaccharide MOD-19. This has been proved by morphological and functional haracteristics of these systems, the increasing of plant biomass and nodules quantiity on the roots. The active functioning period of nodules is elongating at the expense of secondary nodules formation on the side roots and their nitrogen activity increased. Rising of the oxidative ferment activity level for peroxydase and catalase was found in these plants.

Multimodal Treatment of Osteosarcoma Lung Metastases

The diagnostic procedures, role of surgery and multimodal treatment for osteosarcoma pulmonary metastases are examined. From January 2000 to June 2005, we observed 35 patients with osteogenic repetitions. Patients were studied by total-body computerised tomography (CT) and by thoracic single-photon emission computerised tomography (SPECT). Preoperative histological diagnosis was obtained by CT-guided transthoracic needle biopsy (23 cases) and fibre-optic bronchoscopy (12 cases). Four lower, 6 upper and 2 middle lobectomies were carried out using a thoracotomy approach. Video-assisted thoracoscopy was used in the other 23 patients who underwent 36 wedge resections. CT showed a sensitivity of 86 % and a specificity of 66 %; SPECT had a sensitivity of 80 % and a specificity of 100 %. Twenty-five patients are still living 25 +/- 11 months after the intervention. SPECT was demonstrated to offer a better result in the individualisation of secondary pulmonary nodules after primary osteosarcoma. The excision of all resectable lung metastases, integrated in a multidisciplinary strategy, offers good results in terms of survival.

The Ovine Tonsilla Lingualis: Scattered Lymphocyte Aggregations Rather Than a Well‐defined Tonsillar Structure

Recently, it has been hypothesized that the BSE‐causing agent PrPSc can infect sheep, making these animals a possible source of infection for man. Furthermore, experimental studies in inoculated sheep have demonstrated that PrPSc is not only present in neuronal tissue, but also in lymphoid tissue. Therefore, ovine tonsils are considered as high‐risk material and consequently have to be removed after slaughter. The present study is part of an elaborate project in which anatomical, histological and immunological aspects of ovine tonsils are studied within the framework of BSE/TSE research. The tongues of two sheep of 9‐months‐old were collected immediately after slaughter. The lingual root between the base of the epiglottis and the torus linguae was dissected and the 4.5 cm wide and 8 cm long sample was cut into 24 pieces which were subsequently fixed in 3.5% formaldehyde and embedded in paraffin. From each tissue block, ten 8‐μm‐thick sections with 1000 μm interval were cut and stained with eosin–haematoxylin. Microscopic analysis revealed that lymphocytes are mainly present at the lateral side of the tongue forming numerous small aggregates, while in the more central part the amount of aggregates was lower. In both lateral and central parts, the aggregations were located in an area ranging from 1–2 cm till 6 cm rostral to the epiglottis. These lymphatic clusters were in general smaller than the lymphatic nodules seen in the other pharyngeal lymphoid tissue, and a differentiation into secondary nodules was never observed. The epithelium covering these lymphocyte aggregations was a stratified squamous epithelium without infiltration of lymphocytes. It was concluded that the tonsilla lingualis in sheep consists of scattered lymphocyte aggregations without forming a well‐defined tonsillar organization. Further studies are planned to examine the tongues of more sheep and to determine the presence of dendritic cells, follicular dendritic cells and different B‐ and T‐cell populations.This study was supported by the BOF project grant #011B4101 of Ghent University.

Self-Organization Process of Secondary Crystal Nodules from Individual Nuclei in Electrodeposition

Using nonequilibrium fluctuations in electrodeposition, the self-organization process of secondary crystal nodules from individual nuclei was examined. As a result, it was concluded that electrodeposition can be described by two types of fluctuation, i.e., symmetrical and asymmetrical fluctuations; the former yields three-dimensional (3D) nuclei, whereas the latter yields two-dimensional (2D) nuclei that determine the spatial distribution of the 3D nuclei. The complex self-organization of these two types of nuclei leads to the aggregation of each 3D nucleus. In the present paper, first, the instability of these fluctuations was discussed. Then, it was shown that asymmetrical fluctuations control the total reaction rate, and lead to nucleation currents in silver nucleation. Finally, the crystal morphology yielded by the symmetrical and asymmetrical fluctuations was visualized by computer calculation, and the aggregation process of 3D nuclei to secondary nodules was examined.

Anatomical localisation and histology of the ovine tonsils

The topography and histologic structure of the various tonsils were studied anatomically and microscopically in 15 sheep aged between 9 and 15 months. The palatine, pharyngeal and paraepiglottic tonsils were readily visible macroscopically. They consisted mainly of secondary lymph nodules and were encapsulated in dense connective tissues. The epithelium covering the tonsils and their crypts was frequently infiltrated heavily by lymphocytes. The tubal tonsil and the tonsil of the soft palate were macroscopically visible after fixation in 2% acetic acid. These tonsils consisted of scattered lymph nodules, aggregations of lymphocytes and diffuse lymphoid tissue. They were not encapsulated, and therefore the borders of these tonsils could not be clearly delineated. The lingual tonsil was not macroscopically visible in sheep and consisted of scattered small aggregations of lymphocytes.

Occult lung infarction may induce false interpretation of 18F-FDG PET in primary staging of pulmonary malignancies

The aim of the present report is to describe abnormal (18)F-fluorodeoxyglucose (FDG) accumulation patterns in the pleura and lung parenchyma in a group of lung cancer patients in whom lung infarction was present at the time of positron emission tomography (PET). Between November 2002 and December 2003, a total of 145 patients (102 males, 43 females; age range 38-85 years) were subjected to whole-body FDG PET for initial staging (n=117) or restaging (n=11) of lung cancer or for evaluation of solitary pulmonary nodules (n=17). Of these patients, 24 displayed abnormal FDG accumulation in the lung parenchyma that was not consistent with the primary lesion under investigation (ipsilateral n=12, contralateral n=9 or bilateral n=3). Without correlative imaging, this additional FDG uptake would have been considered indeterminate in differential diagnosis. Of the 24 patients who were identified as having such lesions, six harboured secondary tumour nodules diagnosed as metastases, while in three the diagnosis of a synchronous second primary lung tumour was established. Additionally, nine patients were identified as having post-stenotic pneumonia and/or atelectasis (n=6) or granulomatous lung disease (n=3). In the remaining six (4% of all patients), a diagnosis of recent pulmonary embolism that topographically matched the additional FDG accumulation (SUV(max) range 1.4-8.6, mean 3.9) was made. Four of these six patients were known to have pulmonary embolism, and hence false positive interpretation was avoided by correlating the PET findings with those of the pre-existing diagnostic work-up. The remaining two patients were harbouring small occult infarctions that mimicked satellite nodules in the lung periphery. Based on histopathological results, the abnormal FDG accumulation in these two patients was attributed to the inflammatory reaction and tissue repair associated with the pathological cascade of pulmonary embolism. In patients with pulmonary malignancies, synchronous lung infarction may induce pathological FDG accumulation that can mimic active tumour manifestations. Identifying this potential pitfall may allow avoidance of false positive FDG PET interpretation.

Inhibition of the development of pulmonary tumour nodules and stimulation of the activity of NK cells and macrophages in mice by single low doses of low-LET radiation

As indicated by a few recent reports, exposures to low doses of ionising radiation can trigger the activity of natural anti-tumour defence mechanisms and impede the development of transplantable tumours in rodents. In our experimental system, BALB/c mice were irradiated with a single dose of 0.1, 0.2, 0.5, or 1.0 Gy X-rays and then i.v. injected with L1 sarcoma cells. As shown by the results of the lung-colony assay the number of tumour nodules was significantly reduced in the animals exposed to 0.2 Gy in comparison to those irradiated with 0.5 and 1.0 Gy X-rays. This effect was accompanied by the significant stimulation of the activity of NK cells obtained from the spleens of mice exposed to 0.2 and 1.0 Gy as compared to the control, non-irradiated counterparts. However, since the spleen cellularity was substantially reduced by irradiation with 1.0 but not 0.1 or 0.2 Gy and in view of the relatively low radiosensitvity of NK cells compared to B and T lymphocytes, it is possible that the stimulatory effect of 1.0 Gy X-rays resulted from the enrichment of the spleen cell population in natural killer effectors by this dose of X-rays. Moreover, i.p. injection of the anti-asialoGM1 antibody abrogated the differences between the number of tumour cell colonies in the lungs of mice exposed to 0.2 and 1.0 Gy of X-rays. Finally, peritoneal macrophages obtained from mice exposed to 0.1 or 0.2 Gy X-rays and incubated with IFNγ-synthesised significantly greater amounts of nitric oxide than macrophages collected from either the non-irradiated or the 1.0 Gy-exposed mice. However, neither the unstimulated nor the IFNγ-treated macrophages lysed the L1 sarcoma cells in the in vitro assay. The results collectively indicate that the inhibitory effect of 0.2 Gy of X-rays on the development of secondary tumour nodules in mice is associated with the stimulation by this small dose of radiation of the NK cell- and/or macrophage-mediated functions.

Geological and pedological aspects of an Early-Paleolithic site: Revadim, Central Coastal Plain, Israel

An Early Paleolithic site was recently discovered within a sequence of paleosols in the Revadim Quarry, central coastal plain of Israel. The section is composed of three superimposed soils in a continuous sequence, but separated by two unconformity surfaces. The uppermost paleosol is a modern Dark Brown Grumusol (Vertisol), the middle is a Quartzic Gray Brown Soil (Haploxeralf), and the lower is a Red Hamra (Rhodoxeralf). Normal magnetic polarity was detected in the two lower soils, indicating that they are younger than the Brunhes–Matuyama boundary (<780 ka). A human occupation bed, enriched in secondary carbonate nodules, forms the lower part of the Quartzic Gray Brown Soil and overlies the Red Hamra. The living floor is located on top of the unconformity surface, separating the Red Hamra from the overlying Quartzic Gray Brown Soil. Middle to Late Acheulian handaxes, choppers, cores, and flake tools, including tools made by the Levallois technique, and man-laid flint pebbles were excavated in the human occupation bed. In addition, two elephant tusks, an elephant pelvis, an elephant tooth (Palaeoloxodon antiquus), tusk splinters, and bones of equid, suid, cervid, bovid, felid, and rodents were also collected. Based on well-documented nearby boreholes and on regional correlation, it appears that the underlying dune sands, the parent materials from which the Red Hamra developed, were deposited probably during a phase of high-stand sea level of Isotope Stage 9. The Red Hamra developed simultaneously with the human occupation of the site, probably during a phase of low-stand sea-level of Isotope Stage 8, before some 300–245 ka. The overlying dune sands, the parent materials from which the Quartzic Gray Brown Soil developed, were deposited probably during a phase of high-stand sea level of Isotope Stage 7. The climate prevailing in the area during Stage 8, as well as during the human habitation, was moist, with a dense vegetation cover of grassland and probably scattered trees. A small lake of trapped fresh water at a junction of two small tributaries of the Soreq River drainage system near the area occupied was available to hominids and animals. © 1999 John Wiley & Sons, Inc.

Circumscribed lesion of the medial forebrain bundle area causes structural impairment of lymphoid organs and severe depression of immune function in rats.

Interactions between the immune system and the brain are a key element in the pathophysiology of diseases such as multiple sclerosis, neuroAIDS, and Alzheimer's, which affect large numbers of individuals and are associated with a high social cost. However, the neuroanatomical basis of brain-immune interactions has not been elucidated. We report that in Wistar rats of either sex bilateral electrolytic lesion of the medial forebrain bundle reduces body weight by 28% 7 days after lesioning, and causes widespread infections, aphagia, adypsia, structural damage to the lymphoid organs and heavy depression of T lymphocytes cytotoxicity. The following alterations occur in the immune system after those lesions: the weight of the thymus, spleen and lymphonodes is reduced by 77.9%, 49.1% and 48.4%, respectively. The thymus is atrophied and contains fewer lymphoid cells in the cortex than in the medulla. In the spleen the white pulp is reduced and lymphoid cells from periarteriolar zones and at the chords are almost absent. In lymph nodes cortical small lymphocytes are depleted and primary and secondary nodules and germinal centers all but disappear. Cytotoxicity of lymphocytes is reduced by 86.2% in the thymus, 77.6% in the spleen and 70.2% in lymph nodes. The critical area of lesion is at the medialmost portion of the medial forebrain bundle, at the preoptic area and rostral part of the anterior hypothalamus. We suggest that this area contains neural circuits that are crucial for keeping the structure of lymphoid organs and the functional integrity of the immune system.

Dietary fat and breast cancer metastasis by human tumor xenografts

Human breast cancer cell lines growing as xenografts in athymic nude mice have been used to examine the effects of dietary fat and fatty acids on tumor progression. The estrogen independent MDA-MB-435 cell line has the advantage that it metastasizes consistently to the lungs and forms quantifiable secondary nodules when injected into the mammary fat pads. With these breast cancer cells, the stimulating effects of polyunsaturated omega-6 fatty acids on both primary tumor growth and metastasis were demonstrated; in contrast, the long-chain omega-3 fatty acids were inhibitory. The model can also be adapted to examine dietary fatty acids, and inhibitors of their metabolism, as experimental adjuvant therapy after surgical excision of the primary tumors. Unfortunately, estrogen dependent human breast cancer cells do not metastasize, or do so rarely, in nude mice; in consequence, it is not possible to use the model to study estrogen-fatty acid interactions on the metastatic process. In addition to metastasis from a primary location, intravenous injection of MDA-MB-435 cells into the nude mouse host, particularly when combined with studies using Matrigel-based in vitro invasion assays, permits further dissection of the steps in the metastatic cascade which are influenced by dietary fatty acids. The results obtained by these several approaches have demonstrated distinct roles for the cyclooxygenase and lipoxygenase-mediated products of omega-6 fatty acid metabolism, and suggest new approaches to experimental breast cancer therapy.

Cell cycle-dependent expression of the mouse Rad51 gene in proliferating cells.

The mouse Rad51 gene is a mammalian homologue of the Escherichia coli recA and yeast RAD51 genes, both of which are involved in homologous recombination and DNA repair in mitosis and meiosis. The expression of mouse Rad51 mRNA was examined in synchronized mouse m5S cells. The Rad51 transcript was observed from late G1 phase through to M phase. During the period of late G1-S-G2, the RAD51 proteins were observed exclusively in nuclei. Activation by mitogens of T cell and B cell proliferation in spleen induced the expression of Rad51 mRNA. By immunohistochemical analyses, in mouse RAD51 protein was detected in proliferating cells: spermatogonia in testis, immature T cells in thymus, germinal center cells of the secondary lymphatic nodules of spleen and intestine, follicle cells in ovary and epithelial cells in uterus and intestine. It was also expressed in spermatocytes during early and mid-prophase of meiosis and in resting oocytes before maturation. Thus, mouse Rad51 expression is closely related to the state of cell proliferation and is presumably involved in DNA repair coupled with DNA replication, as well as in meiotic DNA recombination in spermatocytes.

Expansion of C4 grasses in the Late Miocene of Northern Pakistan: evidence from stable isotopes in paleosols

Stable-isotopic, clay-mineralogic, and bulk-chemical analyses were conducted on paleosols of the Neogene Siwalik sections in northern Pakistan in order to reconstruct floodplain environments over the past ∼ 17 Ma. The stable carbon isotopic composition of soil carbonate (mean δ13C (PDB) = -10.2%) and associated organic matter (mean δ13C (PDB) = −24.1%) in paleosols representing 17− ∼ 7.3 Ma reveal that floodplain vegetation was dominated by C3 plants. At 7.3 Ma, a shift toward more positive carbon isotopic values began, signaling the gradual expansion of C4 grasses onto the floodplain. From 6 Ma to present, carbon isotopic values for paleosol carbonate (mean δ13C (PDB) = +0.6%) and organic matter (mean δ13C (PDB) = −14.4%) are uniformly enriched in 13C, indicating the presence of nearly pure C4 grassland. The scarcity of kaolinite and abundance of smectite and pedogenic carbonate in most paleosols suggest that rainfall in the region remained 1.0–1.25 m/yr or less for the entire 17 Ma of record. Paleosols in the lower portion of the section lack organic A horizons but have reddish B horizons often containing secondary iron-oxide nodules. Leaching depths of soil carbonate in these older paleosols are typically greater than those in the Plio-Pleistocene part of the section, where organic A horizons are common, and B horizons are markedly more yellow. The combined evidence suggests that the mature paleosols in the pre-7.3 Ma part of the record are dominantly calcareous Alfisols or Mollisols that once underlay nearly pure C3 vegetation, perhaps trees and shrubs, while calcareous Mollisols underlying C4 grassland dominate the upper part of the record. The carbon- and oxygen-isotopic trends in the paleosol record in Pakistan are also evident in the diet of fossil mammals, and in paleosols from Nepal, thus demonstrating that these paleoenvironmental changes in floodplain vegetation may be continent-wide. Local effects, such as the development or intensification of the Asian Monsoon driven by uplift of the Tibetan Plateau, may have led to the expansion of C4 grasses. If, however, the expansion of C4 grasses proves globally synchronous, then a larger scale cause, such as a marked decrease in ϱCO2, may be the driving mechanism.

Interstitial pneumonia in simian immunodeficiency virus infection

Interstitial pneumonia unrelated to Pneumocystis carinii or other infections was observed histopathologically in 5 of 25 rhesus monkeys infected with simian immunodeficiency virus (SIV). The predominant lesion was lymphocytic infiltration of interalveolar septa and hyperplasia of peribronchial and perivascular lymphoid tissue. Immunohistochemical staining using a panel of antibodies against human T and B lymphocytes, macrophages, and immunoglobulins showed that peribronchial aggregates and interstitial infiltrates were predominantly B cells, whereas perivascular masses consisted mainly of T cells. One animal with a primary B-cell lymphoma of the spinal cord had secondary plasmacytoid lymphomatous nodules throughout the lung which were accompanied locally by reactive B-cell lymphoid follicles. Another animal also had large areas of diffuse alveolar fibrosis and epithelial metaplasia to a bronchiolar type. In two monkeys, branches of the pulmonary arteries showed intimal proliferation and organizing occlusive thrombi, some of which were mineralized.

Conditions d'apparition d'une embryogénèse somatique sur des cals issus de la culture de tissus foliaires du chêne vert (Quercus ilex)

The proliferation of parenchymatous foliar tissue of Quercus ilex was obtained from current year leaves taken from old trees and cultivated in vitro on modified Murashige and Skoog's medium supplemented with benzylaminopurine (4 mg ∙ L−1) and naphthyl acetic acid (0.5 mg ∙ L−1). Only the fragments cultured in October reacted. The neoformations only appeared on calluses that had not been subcultured for 7 months. Primary nodules arising on these calluses were removed and subcultured on the same medium either in the dark or in the light. In the dark only, they produced secondary nodules, which were the source of somatic embryos both in light and dark. Presently, they seem to regulate their structure in the dark but they do not develop in a way that leads to germination.

Davis Creek silt, an Early Pleistocene or Late Pliocene deposit in the Cypress Hills of Saskatchewan

Davis Creek silt is the informal name for a previously unreported loess and its reworked detritus encountered at several locations to the south of the east and centre blocks of the Cypress Hills. This unit intervenes between a pediment with an estimated age of 10 Ma and Late Wisconsinan glacial deposits. Because the unit has reversed magnetization, it is older than 788 ka, the astronomical age of the Matuyama–Brunhes magnetic polarity reversal. The unit also contains an undated volcanic ash from the Pearlette ash family that could represent the Mesa Falls (1.27 Ma) or the Huckleberry Ridge (2.02 Ma) ash bed. Davis Creek silt overlies an oxidized weathering zone and contains large secondary carbonate nodules near its truncated top that were, in places, reworked into a lag deposit or stone line before accumulation of the glacial overburden. At one location Davis Creek silt is separated from this overburden by a unit of cryoturbated gravelly loam with remnants of a reddish-yellow paleosolic B horizon.