171 research outputs found
CyPLOS: a new family of synthetic ionophores
The ion transport properties of a new family of synthetic ionophores based on cyclic phosphate-linked oligosaccharide (CyPLOS) macrocycles are described
Cholate Conjugated Polymeric Amphiphiles as Efficient Artificial Ionophores
A family of amphiphilic copolymers containing hydrophobic cholate pendants has been prepared by copolymerization of cholic acid-based monomer 2-(methacryloxy)-ethyl cholate (MAECA) with polyethylene glycol methyl ether methacrylate (PEGMA). The polymers differ for the content of MAECA that increases from 0 to 35%. The copolymers partition within liposomes and display potent ionophoric activity forming large pores in the membrane and allowing the leakage of small inorganic ions (H+, Na+) and of large polar organic molecules (calcein). Their activity is strictly correlated to the content of cholic acid subunits, increasing as the fraction of cholate moiety increases
Evaluation of cytological diagnostic accuracy for canine splenic neoplasms : an investigation in 78 cases using STARD guidelines
Cytology represents a useful diagnostic tool in the preliminary clinical approach to canine splenic lesions, and may prevent unnecessary splenectomy. However, few studies have evaluated diagnostic accuracy of cytology in the diagnosis of canine splenic neoplasms. The aim of this study was to determine overall accuracy, sensitivity, specificity, positive and negative predictive values (i.e. diagnostic accuracy indexes) of cytology for canine splenic neoplasms following Standards for the Reporting of Diagnostic Accuracy Studies (STARD) guidelines. A consecutive series of canine splenic cytological samples was retrospectively retrieved from the database of the Diagnostic Pathology Service of the Department of Veterinary Medicine (DIMEVET\u2014University of Milan). Histopathology was set as the diagnostic reference standard. Cytological cases were enrolled when slides were available for review and when the same lesion was submitted for histopathology. Seventy-eight (78) lesions were included in the study. By histopathology, 56 were neoplastic and 22 were non-neoplastic. Cytology had an overall accuracy of 73.08% (95% C.I. 61.84%-82.50%), sensitivity of 64.29% (95% C.I. 50.36%-76.64%), specificity of 95.45% (95% C.I. 77.16%-99.88%), and positive and negative predictive values of 97.3% (95% C.I. 84.01%-99.60%) and 51.22% (95% C.I. 42.21%-60.15%), respectively. Low sensitivity and negative predictive value were balanced by very high specificity and positive predictive value. When positive for neoplasia, cytology represents a useful diagnostic tool to rule in splenic neoplasia, prompting surgery independently from other diagnostic tests. Conversely, a negative cytological result requires additional investigations to confirm the dog to be disease free
Multifunctional Alternating “Bitter-Sweet” Macromolecular Architecture
The design and synthesis of a multifunctional macromolecular architecture featuring alternating cholic acid and glucose pendants in a polymer side-chain is reported. The target architecture was prepared by reversible addition-fragmentation chain transfer (RAFT) copolymerization of styrene conjugated cholic acid (St-CA: the bitter monomer) and acetyl protected glucose appended maleimide (MI-GLU: the sweet monomer) using polyethylene glycol (PEG) conjugated chain transfer agent (CTA). Removal of the acetates resulted in amphiphilic “bitter-sweet” alternating copolymers that were self-assembled in aqueous media having CA containing bitter core and sugar-coated sweet shell. Dynamic light scattering (DLS) measurements in water, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) confirmed the formation of 40 to 75 nm sized micellar nanoscaffolds, depending on the chain-length of the copolymers. The nanoparticles successfully encapsulated hydrophobic molecules as witnessed via fluorescence spectroscopy using Nile red (NR) as an exemplary guest. Interestingly, the alternating copolymer recognized β-cyclodextrin (β-CD) through the formation of inclusion complexes with lateral cholate moieties in the polymer as evident from 2D NMR and nuclear overhauser effect (NOE) experiments. It is worth noting that the polymer and its inclusion complex were found to be capable of recognizing Concanavalin A (Con A), as shown by turbidimetric assay and isothermal titration calorimetry (ITC). Interestingly, the inclusion complex of the alternating copolymer showed significantly higher autofluorescence in the presence of Con A with respect to that of un-complexed one. Thus, the present study offers a simple way to prepare a multifunctional alternating copolymer having hydrophobic molecule encapsulation, inherent fluorescence, inclusion complex formation with β-CD and lectin recognition capabilities
Chromogenic in situ hybridization for the detection of lambda and kappa immunoglobulin light chains as a potential auxiliary diagnostic technique in canine plasmacytomas
The heterogeneous morphologic features of canine plasmacytomas (PCTs) can make their differentiation from other round cell tumors challenging. Immunohistochemistry (IHC) for lambda (\u3bb) and kappa (\u43a) immunoglobulin (Ig) light chains is often equivocal because of high background staining. The chromogenic in situ hybridization (CISH) technique for light chains has shown higher sensitivity compared to IHC in human plasma cell tumors. Therefore, we aimed to validate automated CISH for light chains in canine tissues and to evaluate its diagnostic potential in canine PCTs, in conjunction with routinely used IHC markers. CISH for light chains demonstrated a clear signal in plasma cell populations of canine control tissues (lymph nodes, lymphoplasmacytic inflammation) showing a polyclonal pattern with a prevalence of \u3bb-producing cells. CISH detected monotypic light chain expression in 33 of 53 (62%) PCTs, 31 expressing \u3bb and 2 expressing \u43a. CISH was more sensitive than IHC for \u3bb light chain (58% vs. 47%, respectively) and more easily interpretable given the absence of confounding background staining. The absence of CISH staining for both \u3bb and \u43a in a considerable subset of tumors may be the result of lower light chain production by neoplastic cells. Multiple myeloma oncogene 1 (MUM1) was expressed by all but 2 PCTs (96%), which showed \u3bb expression by CISH and IHC. The identification of poorly differentiated canine PCTs requires the assessment of a panel of IHC markers, with the potential support of CISH for Ig light chains
Canine smooth muscle tumors: A clinicopathological study
Canine smooth muscle tumors (SMTs) commonly develop in the alimentary and female genital tracts and less frequently in soft tissue. The definition of histological criteria of malignancy is less detailed for SMTs in dogs than in humans. This study evaluated the clinicopathologic features of canine SMTs and compared the veterinary and human medical criteria of malignancy. A total of 105 canine SMTs were evaluated histologically and classified according to both veterinary and human criteria. The Ki67 labeling index was assessed in all SMTs. Estrogen receptor (ER) and progesterone receptor (PR) expression was evaluated for soft tissue SMTs. Follow-up data were available in 25 cases. SMTs were diagnosed in the female genital tract (42%), alimentary tract (22%), and soft tissue (20%). Soft tissue SMTs frequently arose in the perigenital area, pelvic cavity, and retroperitoneum. A subset of soft tissue SMTs expressed ER and/or PR, resembling the gynecologic type of soft tissue SMT in humans. SMTs were less frequently malignant when assessed with human criteria than with veterinary criteria, better reflecting their benign behavior, especially in the genital tract where human criteria tolerate a higher mitotic count for leiomyoma. Decreased differentiation was correlated with increased proliferation, necrosis, and reduced desmin expression. Mitotic count, Ki67 labeling index, and necrosis were correlated with metastases and tumor-related death. Further prognostic studies are warranted to confirm the better performance of the human criteria when assessing SMT malignancy, especially genital cases, to confirm their usefulness in ER/PR-expressing soft tissue SMTs, and to better define the most useful prognostic parameters for canine SMTs
Synthesis and complexing properties of cyclic benzylopeptoids-a new family of extended macrocyclic peptoids
An efficient protocol for the solid-phase synthesis of six members of a new class of extended macrocyclic
peptoids (based on ortho-, meta- and para-N-(methoxyethyl)aminomethyl phenylacetyl units) is
described. Theoretical (DFT) and experimental (NMR) studies on the free and Na+-complexed cyclic
trimers (3\u20135) and tetramers (6\u20138) demonstrate that annulation of the rigidified peptoids can generate
new hosts with the ability to sequestrate one or two sodium cations with the affinities and stoichiometries
defined by the macrocycle morphology. Ion transport studies have been also performed in order to better
appreciate the factors promoting transmembrane cation translocation
Role of Lipophilicity in the Activity of Hexameric Cyclic Peptoid Ion Carriers
Two families of hexameric cyclic peptoids decorated with linear N-alkyl and alternated N-alkyl/N-benzyl side chains (2 a\u2013d and 3 a\u2013c, respectively) were designed and synthesized in order to correlate their logP values (from 2.55 to 6.83) to their ionophoric activities. The present contribution confirms the general ability of hexameric cyclic peptoids to behave as efficient cation carriers, corroborates their preference for Na+ ion, among the tested alkali metals, and suggests a Na+/H+ antiport transport mechanism (rate limited by the transport of the proton) for these new ionophores. Our observations indicate that in order to attain an efficient ionophoric activity, a narrow range of liphophilicity is required (4<5). Moreover, to gain information on the solid state stucture of ionophoric cyclic peptoids with linear N-side chains, X-ray crystallographic studies were performed on exemplar compound 2 a. Crystal structure of compound 2 a confirms the tendency of ionophoric cyclopeptoids with linear N-side chains to form layered assemblies
Neoplastic diseases in the domestic ferret (Mustela putorius furo) in Italy : classification and tissue distribution of 856 cases (2000-2010)
Background: The aim of this study was to describe the prevalence and tissue distribution of neoplasms in Italian ferrets, compared to the epidemiological data previously reported in USA and Japan. Methods: Signalment and diagnoses of pathological submissions received between 2000 and 2010 were searched; cases with the diagnosis of neoplasm were selected and original sections reviewed to confirm the diagnosis. Results: Nine-hundred and ten samples were retrieved, 690 of which included at least one tumour for a total of 856 tumours. Ferrets with multiple neoplasms were 134 (19.4%). Median age was 5years, and F/M ratio was 0.99. Endocrine neoplasms were the most common. Other frequent tumours were cutaneous mast cell tumours, sebaceous tumours, and lymphomas. Cutaneous squamous cell carcinomas (SCC) were consistently associated with sebaceous tumours. Twenty-four abdominal spindle cell tumours with an undefined origin were observed. Lymphomas and islet cell tumours had a lower incidence compared with previous extra-European studies. Discussion: Epidemiological information on ferret tumours derives from extra-European countries, mostly USA and Japan. In these countries similar distributions with minor discrepancies have been reported. Compared to previous reports, adrenal tumours were more frequent than pancreatic islet cell neoplasms, and a higher number of mesenchymal neoplasms arising from the adrenal capsule was noted. An unusual association between SCC and sebaceous gland neoplasms and a high number of intrabdominal spindle cell neoplasms with unclear primary origin were noted and grants further investigation. Conclusions: The tissue distribution of tumours recorded in this study paralleled previous findings in ferrets from USA and Japan. Some differences have been noted in the frequency of lymphoma, adrenal mesenchymal tumours and cutaneous tumours. Some tumours that are among the most common in other species seem to be uncommon in ferrets and are characterized by distinctive predilection sites
Diagnosis and surgical management of malignant ovarian teratoma in a green iguana (Iguana iguana)
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