197 research outputs found

    Optical Characterization of Benign and Malignant Breast Lesions by Perturbative Model

    Get PDF
    The characterization of benign and malignant breast lesions was performed by the use of a perturbative model. Concentrations of blood, lipid, water and collagen were obtained. Differences between lesions and healthy tissue were observed

    Optical response with threefold symmetry axis on oriented microdomains of opal photonic crystals

    Get PDF
    The paper deals with three-dimensional photonic crystals known as artificial opals, namely, fcc lattices of dielectric spheres: such systems have been the subject of numerous investigations. Opal photonic crystals viewed along the [111] direction of the fcc structure have a threefold symmetry axis; however this microscopic symmetry is difficult to observe in optical measurements performed on macroscopic areas containing microdomains with different orientations. In this work polarized transmittance measurements on [111]-stacked silica opals with single oriented microdomains, identified by field-emission scanning electron microscopy and laser-scanning confocal microscopy, demonstrate different optical response of twin structures with the two possible vertical stacking sequences. A detailed comparison with theory shows that microtransmittance experiments probe the photonic band structure along the Gamma-L-K and Gamma-L-U orientations of the Brillouin zone, respectively, thus giving conclusive evidence for macroscopic optical response related to the presence of a threefold (instead of a sixfold) symmetry axis in the photonic microstructure. The paper arises from a collaboration between the University of Pavia and the Politecnico di Torino

    Brain oxygen tension, oxygen supply, and oxygen consumption during arterial hyperoxia in a model of progressive cerebral ischemia

    Get PDF
    We investigated the changes in brain oxygen tension (ptiO(2)) after ventilation with pure O-2 in order to (1) clarify the pathophysiology of O-2 exchange in the cerebral microcirculation; and (2) investigate the relationship between brain O-2 tension, O-2 delivery, and consumption in steady-state conditions during stepwise cerebral blood flow (CBF) reductions. A swine model was developed to reduce CBF in three stable steps: (1) baseline (CBF 100%), (2) CBF of 50-60% of baseline, and (3) CBF of (30% of baseline. CBF was reduced by infusing saline into the left lateral ventricle through a catheter connected with an infusion pump. At each step, hyperoxia was tested by increasing the inspired oxygen fraction up to 100%, PtiO(2) reflected the CBF reductions, since it was respectively 27.95 ( +/-10.15), 14.77 (+/-3.58), and 3.45 (+/-2.89) mm Hg during the three CBF steps. Hyperoxia was followed by an increase in ptiO(2), although the increase was significantly lower when hyperoxia was applied during progressive ischemia. O-2 supply to the brain did not change during hyperoxia. Arteriovenous oxygen difference (AVDO(2)) decreased during the phases of intact CBF and moderate impairment, but not during the phase of severe CBF reduction. In conclusion, ptiO(2) reductions closely reflect the imbalance between oxygen delivery and demand; this implies a link between low ptiO(2) and defective O-2 supply due to impaired CBF. However, this relation is not necessarily reciprocal, since manipulating brain oxygen tension does not always influence brain oxygen delivery, as in the case of ventilation with pure oxygen

    Vascular Dementia Italian Sulodexide Study (VA.D.I.S.S.) Clinical and biological results

    Get PDF
    In order to evaluate the biological effects on some haemostasis factors of antithrombotic-hemorheological treatments on patients with vascular dementia, a multicenter, randomized, double-blind, double-dummy, study comparing sulodexide (Sdx, 50 mg bid orally for 6 months) and pentoxifylline (Ptx, 400 mg tid orally for six months) was carried out. Eighty-six patients, 46 in Sdx group, 40 in Ptx group, fulfilling the NINDS-AIREN criteria for probable vascular dementia were evaluated. Plasma fibrinogen levels showed a significant reduction in both groups, in patients with high basal levels (≤350 mg/dl), the reduction being earlier in Sdx group (2nd month of therapy) than in Ptx group (4th month of therapy). In Sdx group a significant reduction in factor VII-Ag (baseline 102.8 U/dl; 6th month 90.1 U/dl) was also observed. Both drags induced a slight reduction in activated factor VII levels as well. A parallel improvement of G.B.S. Rating Scale for dementia scores was observed in Sdx group. These results seem to indicate that sulodexide treatment can have positive effects in vascular dementia

    Diagnostic precision of image-guided multisampling core needle biopsy of suspected lymphomas in a primary care hospital

    Get PDF
    We evaluated the diagnostic quality of image-guided multisampling core needle biopsy (CNB) in patients investigated for suspected lymphoma in a primary care hospital. A total of 112 patients were consecutively assessed during a 3-year period. There were 80 lymphoid site biopsies and 32 non-lymphoid site biopsies. Eight to nine cores were obtained from different parts of the biopsy site. Two cores were systematically frozen, allowing for further morphological, immunochemistry and molecular studies. The diagnostic yield of CNB for malignancy was 100%. Only 47% (41/87) of patients with initial suspicion of lymphoma were finally diagnosed with Lymphoma. The diagnostic yield of CNB for lymphoma typing was 98% (62/63), according to the WHO classification. The diagnostic yield of CNB for complete lymphoma subtyping/grading was 86% (54/63). The diagnostic yield of CNB for a definite diagnosis of benignity was only 47% (8/17). In a primary care setting, multisampling CNB is a minimally invasive, and very accurate procedure for confirming malignancy in patients with suspected lymphoma, presenting with superficial/deep-seated, lymphoid/non-lymphoid site targets. With a very high diagnostic yield for lymphoma typing and a high diagnostic yield for complete lymphoma subtyping/grading a therapeutic decision can be taken in most patients

    Vascular Dementia Italian Sulodexide Study (VA.D.I.S.S.) Clinical and biological results

    Get PDF
    In order to evaluate the biological effects on some haemostasis factors of antithrombotic-hemorheological treatments on patients with vascular dementia, a multicenter, randomized, double-blind, double-dummy, study comparing sulodexide (Sdx, 50 mg bid orally for 6 months) and pentoxifylline (Ptx, 400 mg tid orally for six months) was carried out. Eighty-six patients, 46 in Sdx group, 40 in Ptx group, fulfilling the NINDS-AIREN criteria for probable vascular dementia were evaluated. Plasma fibrinogen levels showed a significant reduction in both groups, in patients with high basal levels ( 64350 mg/dl), the reduction being earlier in Sdx group (2nd month of therapy) than in Ptx group (4th month of therapy). In Sdx group a significant reduction in factor VII-Ag (baseline 102.8 U/dl; 6th month 90.1 U/dl) was also observed. Both drags induced a slight reduction in activated factor VII levels as well. A parallel improvement of G.B.S. Rating Scale for dementia scores was observed in Sdx group. These results seem to indicate that sulodexide treatment can have positive effects in vascular dementia

    Thick calcification from a GIST of the stomach penetrating into pericolic soft tissue - report of a case

    Get PDF
    Thick calcification is a rare presentation of gastrointestinal stromal tumor (GIST). Penetration into gastric mucosa and pericolic soft tissue has never been reported. We report a case of gastric GIST with cystic degeneration and thick calcification in an 81-year old female, who presented with hematemesis and severe abdominal pain. Thick calcification of this tumor penetrating into pericolic soft tissue was noted and successfully treated by distal gastrectomy and partial colectomy. For gastrointestinal tumors with thick calcification, even with benign behavior, surgical intervention should be considered for both oncological considerations and prevention of catastrophes like perforation or penetration into surrounding soft tissue

    Genetic tool development in marine protists: emerging model organisms for experimental cell biology

    Get PDF
    Diverse microbial ecosystems underpin life in the sea. Among these microbes are many unicellular eukaryotes that span the diversity of the eukaryotic tree of life. However, genetic tractability has been limited to a few species, which do not represent eukaryotic diversity or environmentally relevant taxa. Here, we report on the development of genetic tools in a range of protists primarily from marine environments. We present evidence for foreign DNA delivery and expression in 13 species never before transformed and for advancement of tools for eight other species, as well as potential reasons for why transformation of yet another 17 species tested was not achieved. Our resource in genetic manipulation will provide insights into the ancestral eukaryotic lifeforms, general eukaryote cell biology, protein diversification and the evolution of cellular pathways. This article has 113 total authors; only 32 are listed here
    • …
    corecore