Microfilaruria of Dirofilaria immitis in a dog from Italy

Dirofilaria immitis is a mosquito-borne nematode-causing canine heartworm disease, with adult worms localized in the pulmonary arteries and right heart. In rare cases, ectopic migration might occur, and adults and blood circulating microfilariae can be found in unusual organs or fluids (e.g., eyes, abdominal cavity, bone marrow, and urine). A 17-year-old mixed-breed female dog was presented in a private veterinary clinic in Italy for hematuria and dysuria. Physical examination showed cardiac mitral murmur with marked respiratory distress and cyanotic mucous membranes after handling. Abdominal ultrasounds revealed a non-specific chronic cystopathy, while the echocardiography showed enlargement of the right heart associated with tricuspid insufficiency and mitral regurgitation, with the presence of an adult filariae in the right ventricular chamber. Circulating microfilariae were observed in the blood smear and molecularly identified as D. immitis. Unusual microfilaruria was detected in the urine sediment. Data presented raise awareness about the occurrence of microfilariae in unusual locations, such as the bladder, suggesting the need of a thorough clinical and laboratory assessment where D. immitis is endemic.

Low-molecular-weight heparin for the prevention of clinical worsening in severe non-critically ill COVID-19 patients: a joint analysis of two randomized controlled trials

Coronavirus disease 2019 (COVID-19) carries a high risk of vascular thrombosis. However, whether a specific anticoagulation intensity strategy may prevent clinical worsening in severe COVID-19 patients is still debated. We conducted a joint analysis of two randomized controlled trials, COVID-19 HD (NCT044082359) and EMOS-COVID (NCT04646655), to assess the efficacy and safety of two anticoagulant regimens in hospitalized severe COVID-19 patients. Subjects with COVID-19-associated respiratory compromise and/or coagulopathy were randomly assigned to low (4000 IU qd) or high (70 IU Kg-1 every 12 h) enoxaparin dose. The primary efficacy endpoint was clinical worsening within 30 days, defined as the occurrence of at least one of the following events, whichever came first: in-hospital death, evidence of arterial or venous thromboembolism, acute myocardial infarction, need for either continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) in patients receiving standard oxygen therapy or none at randomization, and need for mechanical ventilation in any patient. The safety endpoint was major bleeding. We estimated the relative risk (RR) and its 95% confidence interval (CI) for the outcomes. Among 283 patients included in the study (144 in the low-dose and 139 in the high-dose group), 118 (41.7%) were on NIV or CPAP at randomization. 23/139 (16.5%) patients in the high-dose group reached the primary endpoint compared to 33/144 (22.9%) in the low-dose group (RR 0.72, 95% CI 0.45-1.17). No major bleeding was observed. No significant differences were found in the clinical worsening of hospitalized COVID-19 patients treated with high versus low doses of enoxaparin.

Novel Insights into the Antagonistic Effects of Losartan against Angiotensin II/AGTR1 Signaling in Glioblastoma Cells

Simple Summary

Patients with high-grade glioma (HGG) such as glioblastoma (GBM) who undergo surgical resection with adjuvant therapy have a mean overall survival of 14.6 months and 100% of recurrence. Thus, these disappointing outcomes in terms of glioblastoma life expectancy require seeking novel pharmacological tools, including drug repurposing. In the present study, we identify a novel molecular mechanism through which Losartan antagonizes Angiotensin II (Ang II)/Angiotensin II type I receptor (AGTR1) signaling, overexpressed in GBM cells. For instance, we demonstrate how Losartan drastically inhibits the stimulatory effects of Ang II on aromatase activity and consequently reduces local estrogen production, sustaining cancer progression. Thus, it is reasonable to repurpose Losartan as an adjuvant pharmacological tool to be implemented prospectively in the novel therapeutic strategies adopted in GBM patients.

Abstract

New avenues for glioblastoma therapy are required due to the limited mortality benefit of the current treatments. The renin-angiotensin system (RAS) exhibits local actions and works as a paracrine system in different tissues and tumors, including glioma. The glioblastoma cell lines U-87 MG and T98G overexpresses Angiotensin II (Ang II)/Angiotensin II type I receptor (AGTR1) signaling, which enhances in vitro and in vivo local estrogen production through a direct up-regulation of the aromatase gene promoters p I.f and p I.4. In addition, Ang II/AGTR1 signaling transactivates estrogen receptor-α in a ligand-independent manner through mitogen-activated protein kinase (MAPK) activation. The higher aromatase mRNA expression in patients with glioblastoma was associated with the worst survival prognostic, according to The Cancer Genome Atlas (TCGA). An intrinsic immunosuppressive glioblastoma tumor milieu has been previously documented. We demonstrate how Ang II treatment in glioblastoma cells increases programmed death-ligand 1 (PD-L1) expression reversed by combined exposure to Losartan (LOS) in vitro and in vivo. Our findings highlight how LOS, in addition, antagonizes the previously documented neoangiogenetic, profibrotic, and immunosuppressive effects of Ang II and drastically inhibits its stimulatory effects on local estrogen production, sustaining glioblastoma cell growth. Thus, Losartan may represent an adjuvant pharmacological tool to be repurposed prospectively for glioblastoma treatment.

Leptin and Notch Signaling Cooperate in Sustaining Glioblastoma Multiforme Progression

Glioblastoma multiforme (GBM) is the most malignant form of glioma, which represents one of the commonly occurring tumors of the central nervous system. Despite the continuous development of new clinical therapies against this malignancy, it still remains a deadly disease with very poor prognosis. Here, we demonstrated the existence of a biologically active interaction between leptin and Notch signaling pathways that sustains GBM development and progression. We found that the expression of leptin and its receptors was significantly higher in human glioblastoma cells, U-87 MG and T98G, than in a normal human glial cell line, SVG p12, and that activation of leptin signaling induced growth and motility in GBM cells. Interestingly, flow cytometry and real-time RT-PCR assays revealed that GBM cells, grown as neurospheres, displayed stem cell-like properties (CD133+) along with an enhanced expression of leptin receptors. Leptin treatment significantly increased the neurosphere forming efficiency, self-renewal capacity, and mRNA expression levels of the stemness markers CD133, Nestin, SOX2, and GFAP. Mechanistically, we evidenced a leptin-mediated upregulation of Notch 1 receptor and the activation of its downstream effectors and target molecules. Leptin-induced effects on U-87 MG and T98G cells were abrogated by the selective leptin antagonist, the peptide LDFI (Leu-Asp-Phe-Ile), as well as by the specific Notch signaling inhibitor, GSI (Gamma Secretase Inhibitor) and in the presence of a dominant-negative of mastermind-like-1. Overall, these findings demonstrate, for the first time, a functional interaction between leptin and Notch signaling in GBM, highlighting leptin/Notch crosstalk as a potential novel therapeutic target for GBM treatment.

Pneumothorax and pulmonary hemorrhage after CT-guided lung biopsy: incidence, clinical significance and correlation

OBJECTIVES

To evaluate the incidence and clinical significance of pneumothorax (PTX) and pulmonary hemorrhage (PH) after CT-guided lung biopsy (CT-LB). To test correlations of PTX and chest tube insertion (CTI) with PH and other imaging and procedural parameters.

METHODS

Pre-procedural CT and CT-LB scans of 904 patients were examined. Incidence of PTX and PH and PH location (type-1 along needle track; type-2 perilesional) and severity according to its thickness (low grade < 6 mm; high grade > 6 mm) were recorded. PTX was considered clinically significant if treated with CTI, PH if treated with endoscopic/endovascular procedure. Binary logistic regression analyses were used to determine the effects of different imaging and procedural parameters on the likelihood to develop PTX, CTI and PH and to define their correlation.

RESULTS

PTX occurred in 306/904 cases (33.8%); CTI was required in 18/306 (5.9%). PH occurred in 296/904 cases (32.7%), and no case required treatment. Nodule-to-pleura distance (OR_PTX = 1.052; OR_CTI = 1.046; OR_PH 1.077), emphysema (OR_PTX = 1.287; OR_PH = 0.573), procedure time (OR_PTX = 1.019; OR_CTI = 1.039; OR_PH = 1.019), target size (OR_PTX = 0.982; OR_PH = 0.968) and needle gauge (OR_PTX = 0.487; OR_CTI = 4.311; OR_PH = 2.070) showed statistically significant correlation to PTX, CTI and PH. Type-1 PH showed a protective effect against PTX and CTI (OR_PTX = 0.503; OR_CTI = 0.416).

CONCLUSION

PTX and PH have similar incidence after CT-guided lung biopsy. PH along needle track may represent a protective factor against development of PTX and against PTX requiring CTI.

Radiofrequency ablation (RFA) of T1a renal cancer with externally cooled multitined expandable electrodes

INTRODUCTION

To retrospectively evaluate the mid-term outcomes of percutaneous radiofrequency ablation (RFA) with multitined expandable electrodes externally cooled with saline solution in patients with T1a renal cell carcinoma (RCC).

MATERIALS AND METHODS

In this retrospective study, we evaluated 39 RCC in 35 patients treated with CT-guided RFA in 41 procedures (2011-2017). All patients were staged T1a, N0, M0 prior to RFA. Mean tumor size was 24.48 mm. A 4-tined expandable RFA electrode cooled with pump-circulating saline was used. Efficacy was evaluated verifying complete tumor necrosis (no contrast enhancement on imaging) at the end of the procedure and on subsequent controls. Follow-up observation period was 5 years. Minor/major complications, hospitalization days, serum creatinine and GFR pre- and post-RFA (compared using paired t test) and post-operative pain (evaluated with NRS after treatment) were considered as safety indicators. Overall survival was also calculated (Kaplan-Meier method).

RESULTS

Of 35 patients, 30/35 had 1 treatment (primary effectiveness rate 86%), 4/35 had 2 treatments and 1/35 had 3 treatments for residual disease. There were no relapses and no mid-long-term complications; 3 minor (8%) and 1 major (2.7%) complications during perioperative period were reported. Mean before and after RFA serum creatinine rates were, respectively, 1.08 mg/dl and 1.11 mg/dl (p value: 0.4117). NRS median value is 0.8. Hospitalization days median value is [2.8 ± 1.9] days. 91.4% of all patients survived, with a median overall survival time of 65 months.

CONCLUSIONS

Mid-term results show that CT-guided RFA with multitined expandable electrodes externally cooled with saline solution is an effective and safe treatment in patients with RCC-staged T1aN0M0. Data reported in our study are in line with data reported in the literature from patients treated with other devices.

Magnetic resonance imaging of adrenal gland: state of the art

Detection of adrenal lesions, because of the widespread use of imaging and especially high-resolution imaging procedures, is increased. Because of the importance to characterize those findings, magnetic resonance imaging (MRI), in particular chemical shift imaging (CSI), is useful to distinguish whether a lesion is benignant or malignant and to avoid further diagnostic or surgical procedures. It represents the first choice of imaging in patient like children or pregnant women, and a valid complement to other imaging techniques like CT or PET/CT. In this review we analyze the role and characteristic of MRI and the imaging features of most common benignant (adenoma, hyperplasia, pheochromocytoma, hemorrhage, cyst, myelolipoma, teratoma, ganglioneuroma, cystic lymphangioma, hemangioma) and malignant [neuroblastoma, adrenocortical carcinoma (ACC), metastases, lymphoma] adrenal lesions.

Ultrasound-guided percutaneous irrigation of calcific tendinopathy: technical developments

Rotator cuff calcific tendinopathy (RCCT) is a common and painful shoulder disease characterised by deposition of calcium into the rotator cuff’s tendond. Different therapeutic options have been proposed, but the ultrasound-guided percutaneous irrigation (US-PICT) is been proved as an effective and safe first-line treatment. It can be performed with a single- of a double-needle tecnique, using warm saline solution to improve the dissolution of the calcific deposit. The procedure is ended with an intrabursal injection of local anaesthetics and slow-release steroids to improve the pain relief and to prevent complications. US-PICT leads to significative improvement in the shoulder funtion and pain relief in the short and long term, with a low complications rate. (www.actabiomedica.it)

Percutaneous needle biopsy of retroperitoneal lesions: technical developments

Percutaneous Needle Biopsy (PNB) is the insertion of a needle into a suspected lesion or an organ with the aim to obtain cells or tissue for diagnosis. It’s a relatively non-invasive procedure and is performed by radiologist under guidance of imaging techniques such as ultrasound (US), computed tomography (CT), fluoroscopy, magnetic resonance imaging (MRI), and positron emission tomography CT (PET-CT). The choice of imaging technique depends on the evaluation of the target lesion and patient compliance. PNB includes two categories: fine-needle aspiration biopsy (FNAB) that is the use of a thin needle (18-25 gauge) to extract cells for cytological evaluation; and core needle biopsy (CNB) that is the use of a larger needle (9-20 gauge) to extract a piece of tissue for histological evaluation. The indications for biopsy are the characterization of nature (benign or malignant) of a lesion, diagnosis and staging of tumor, and biological or immunohistochemical/genetic analisys on tissue. Success of PNB is the procurement of sufficient material to characterize lesions and to guide the patient outcome. Major complications are rare. PNB became a useful technique in diagnosis and study of retroperitoneal lesions, because of a more suitable access to specific intra-abdominal structures, lowering the risk of injury of interposed structures (such as bowel, great vessels). (www.actabiomedica.it)

Transthoracic computed tomography-guided lung biopsy in the new era of personalized medicine

Computed tomography-guided lung biopsy is a valid and safe procedure for characterizing pulmonary nodules. In the past years, this technique has been mainly used to confirm the malignant nature of undetermined pulmonary lesions; however, today its role has been completely renewed. With the advent of target therapy and immunotherapy, it has arisen for lung cancer, in inoperable patients, the necessity to obtain adequate bioptical material to perform a correct molecular characterization of the lesion. Moreover, the possibility of acquired drug-resistance mechanisms makes it necessary in some cases to rebiopsy these lesions over time. For these reasons, it is likely that the request of computed tomography-guided lung biopsy will increase in the future, therefore every radiologist should be confident with its most important aspects.

Imaging after radiofrequency ablation of renal tumors

The number of percutaneous radiofrequency ablation procedures performed for renal tumors is progressively increasing worldwide. Periodic imaging follow-up has the double role to guarantee the treatment efficacy over time and to early detect any possible complication. Tumor size reductions, as well as the appearance of the characteristic ‘halo sign’, are normal findings that represent good ablative outcomes. However the most reliable factor of ablation efficacy remains the total absence of contrast enhancing zones within the ablated area. The aim of this article is to illustrate the typical aspect of an effective radiofrequency ablation treatment, which are the imaging findings that may suggest the presence of residual tumoral tissue and which are the main early and late procedural complications.

β-TG and Plasma Catecholamines Levels after Sympathetic Stimuli in Hypertensives and Patients with Peripheral Vascular Disease

The influence of the sympathetic nervous system on platelet functions in vivo is still controversial. The aims of our study were to compare the response to various sympathetic stimuli in normal subjects and in patients with essential hypertension (HT) or peripheral vascular disease (PVD) and to evaluate any correlations among plasma levels of catecholamines, beta-thrombo-globulin (β-TG) and platelet factor 4 (PF4). In basal conditions β-TG and PF4 values in the HT patients were higher than those observed in the controls of the same age but lower than those of the PVD patients. Although the different sympathetic stimuli (90° tilting, handgrip, treadmill test, bicycle test) caused a significant increase of the plasma epinephrine (E) and norepinephrine (NE) levels, they did not modify the β-TG and PF4 levels in any of the groups studied. The platelet activation indices, therefore, regardless of the basal values, do not seem to be influenced by sympathetic stimulation.

Radiofrequency ablation of osteoid osteoma

Osteoid osteoma is a benign bone neoplasm with a reported incidence of 2-3% among all bone primary tumors. Although it is a small and benign lesion, it is often cause of patient complaint and discomfort. It is generally characterized by a long lasting, unremitting pain that typically exacerbates at night, often leading to sleep deprivation and functional limitation of the skeletal segment involved, with a significant reduction of patient daily life activities and consequent worsening of the overall quality of life. Over decades, complete surgical resection has represented the only curative treatment for symptomatic patients. In the last years, new percutaneous ablation techniques, especially radiofrequency ablation, have been reported to be a safe and effective alternative to classical surgery, with a low complication and recurrence rate, and a significant reduction in hospitalization cost and duration. The aim of this article is to provide an overview about the radiofrequency thermal ablation procedure in the treatment of osteoid osteoma. (www.actabiomedica.it)

Developments in the management of bone metastases with interventional radiology

Interventional radiology has known an exponential growth in the last years. Technological advances of the last decades, have made it possible to use new treatments on a larger scale, with safe and effective results. They could be considered as palliative treatments for painful lesions but also curative procedures, as single treatment or specially in combination with other techniques (surgery, radiation and oncology therapies, etc.). The main diffuse techniques are those of thermal ablation that destroy the target lesion through the heat; however there are also endovascular therapies that destroy the target tissue thanks to devascularization. Finally the is also the possibility to stabilize pathological fractures or impending fractures. In this paper all the most diffuse and effective techniques are reviewed and also a discussion of the main indications is done, with an analisys of the success and complications rates. (www.actabiomedica.it)

Imaging of pediatric foot disorders

Infants and children undergo imaging studies to evaluate a wide variety of congenital and acquired disorders. Imaging protocols have to consider the patient’s comfort, level of anxiety, and smaller size. The first imaging study is usually made with plain radiographs. The routine radiographic examination of the foot includes the anteroposterior (AP), lateral, and oblique projections. Magnetic Resonance Imaging (RMI) provides excellent anatomic detail of cartilage, vasculature and soft tissue thanks to superior soft tissue contrast and spatial resolution, so is valuable in many cases. According to the clinical and objective signs, guided by the radiographs images, we can be oriented to perform Computed Tomography (CT), CT imaging or MRI imaging. CT imaging is useful to observe the bones but it has the disadvantage of using radiation and doesn’t adequately define the bone’s non-ossified portions. On the contrary, MRI imaging is very useful in identifying the cartilaginous parts and vascular and soft tissues, thanks to its superior contrast and spatial resolution. Finally, it is important to orientate the diagnostic process keeping in mind the clinical sign of the patient and to use the most appropriate diagnostic technique. (www.actabiomedica.it)

Synthesis, Spectroscopic Characterization and Crystal and Molecular Structures of {Ph4P[(Se04 )(SnPh3 )(SnPh3X)]}n (X = Cl, Br)

The reactions of bis[triphenyltin(IV)] selenate monohydrate [(Ph3Sn)2O4Se · H2O ] with tetraphenylphosphonium halides Ph4PX (X = Cl, Br) led to the formation of 1:1 complexes of formula {Ph4P[(SeO4)(SnPh3 (SnPh3X)]k [X = Br (I) or Cl (II)], which were characterized by infrared, Mössbauer and H, 13C and Sn 119Sn NMR techniques and by X-ray diffractometry. The complexes have polymeric structures in which the [SnPh3]+ units alternate with bridging [SeO4]2- units, each of which also bears an SnPh3X side chain. In both the [SnPh3]+ and the [SnPh3X] units the coordination polyhedron of the tin atom is a distorted trigonal bipyramid.

Evaluation of penile cavernosal artery intima-media thickness in patients with erectile dysfunction. A new parameter in the diagnosis of vascular erectile dysfunction. Our experience on 59 cases

OBJECTIVE

A precise characterization of erectile dysfunction (ED) of vascular origin has not yet been achieved, although cavernous peak systolic velocity (PSV) is generally considered a major parameter. Nevertheless the penile dynamic color Doppler is invasive and linked to several complications. The intima-media thicknesses (IMT) of cavernosal artery would add to the predictive value of vasculogenic ED risk and outcomes. We also hypothesized the existence of a correlation between IMT cavernosal artery and IMT carotid arteries. This study seeks to evaluate these hypotheses with our experience, investigating the predictive accuracy of carotid and cavernosal Doppler ultrasound findings for discriminating patients with vasculogenic ED.

MATERIAL AND METHODS

A total of 59 subjects (32 vasculogenic ED patients - group A - and 27 no vasculogenic ED patients - group B) were evaluated in our andrological center from September 2012 to June 2013 and enrolled in the study. All subjects underwent medical history, erectile function domain of the International Index of Erectile Function, physical examination, routine and sex hormone blood tests, and high resolution dynamic color Doppler ultrasound evaluation of carotid and penile districts and valuation of IMT in both districts.

RESULTS

The values of cavernosal artery IMT in group A were higher than in group B (0,28 ± 0,06 mm vs 0,17 ± 0,07 mm). Even the values of carotid artery IMT in vasculogenic ED group were higher than in no vasculogenic ED group (0,74 ± 0,14 mm vs 0,59 ± 0,11 mm). The cavernosal IMT showed a moderate (r = 0.61) positive linear correlation (p < 0.001) with the carotid artery IMT.

CONCLUSIONS

An increased cavernous IMT might predict ED of vascular origin with more accuracy than PSV and could be a sensitive predictor also for systemic atherosclerosis at an earlier phase.

Portal vein thrombosis in inflammatory bowel diseases: a single-center case series

BACKGROUND AND METHODS

Portal vein thrombosis (PVT) has been reported as a complication of IBD in some case reports. We describe the presentation, diagnostic approaches, underlying risks factors and clinical outcome of 8 IBD patients with PVT. CASE-SERIES: The patients presented with partial PVT (4 patients) or portal cavernoma. Five patients had undergone surgery. In 2 patients portal biliopathy was diagnosed after detection of PVT. In 4 patients, the diagnosis of PVT was made while IBD was in remission. Five patients showed at least one risk factor for hypercoagulability: lupus anti-coagulant (one patient), increased von Willebrand factor (2 patients) or homocysteine levels (4 patients). Four patients received anticoagulant therapy for 6 months. None experienced other thrombotic events during a median of 5 years (range 2-8 years).

CONCLUSION

PVT is a potential complication of IBD, usually associated with acquired or inherited risks factors for hypercoagulability and with a benign outcome.

Organotin meclofenamic complexes: Synthesis, crystal structures and antiproliferative activity of the first complexes of meclofenamic acid - novel anti-tuberculosis agents

The complexes [Me(2)(Meclo)SnOSn(Meclo)Me(2)](2) (2) and [Ph(3)Sn(Meclo)] (3) where HMeclo is meclofenamic acid, N-(2,6-dichloro-m-tolylanthranilic acid)], have been prepared and structurally characterized by means of vibrational, (1)H and (13)C NMR spectroscopies. The crystal structure of complexes (2) and (3) have been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement of (2). The structure is centro symmetric and features a central rhombus Sn(2)O(2) unit two additional tin atoms linked at the oxygen atoms. Five- and six-coordinated tin centers are present in the dimer distannoxane. X-ray analysis of (3) revealed a penta-coordinated structure containing Ph(3)Sn coordinated to the chelated carboxylato group. The polar imino hydrogen atom participates in intra-molecular hydrogen bonds. Complexes (2) and (3) are self-assembled via pi-->pi, C-H-pi, stacking interactions and intra-molecular hydrogen bonds. Meclofenamic acid and [Ph(3)Sn(Meclo)] have been evaluated for antiproliferative activity in vitro against three human cancer cell lines: MCF-7 (human breast cancer cell line), T24 (bladder cancer cell line), A-549 (non-small cell lung carcinoma) and a mouse L-929 (a fibroblast-like cell line cloned from strain L). The [Ph(3)Sn(Meclo)] complex exhibited high cytotoxic activity against all the cancer cell lines. Meclofenamic and [Ph(3)Sn(Meclo)] were tested for anti-mycobacterial activity against Mycobacterium tuberculosis H37Rv. The [Ph(3)Sn(Meclo)] complex was found to be a promising anti-mycobacterial lead compound, displaying high activity against M. tuberculosis H37Rv.

Interaction of NO with nanosized Ru-, Pd-, and Pt-Doped SnO2: electron paramagnetic resonance, Mössbauer, and electrical investigation

The mechanism of NO interaction with nanosized Ru(Pd,Pt)-doped SnO(2) was studied by electron paramagnetic resonance, Mössbauer, and electric resistance measurements. Three steps were proposed for the reaction between the semiconductor oxide and the gaseous component: (i) the formation of bielectronic oxygen vacancies (V(o)) in SnO(2); (ii) their single-ionization (V(o)(*)) with injection of electrons into the SnO(2) conduction band; (iii) the subsequent transfer of electrons from V(o)(*) to [Ru(Pd,Pt)](4+). The last process induces the formation of further oxygen vacancies which reduce the transition metal centers to lower oxidation states; the redox processes is enhanced and the electrical resistance in transition metal-doped SnO(2) is stronger modified with respect to the undoped material.

Interaction of NO with Nanosized Ru-, Pd-, and Pt-Doped SnO2: Electron Paramagnetic Resonance, Mössbauer, and Electrical Investigation

The mechanism of NO interaction with nanosized Ru(Pd,Pt)-doped SnO(2) was studied by electron paramagnetic resonance, Mössbauer, and electric resistance measurements. Three steps were proposed for the reaction between the semiconductor oxide and the gaseous component: (i) the formation of bielectronic oxygen vacancies (V(o)) in SnO(2); (ii) their single-ionization (V(o)(*)) with injection of electrons into the SnO(2) conduction band; (iii) the subsequent transfer of electrons from V(o)(*) to [Ru(Pd,Pt)](4+). The last process induces the formation of further oxygen vacancies which reduce the transition metal centers to lower oxidation states; the redox processes is enhanced and the electrical resistance in transition metal-doped SnO(2) is stronger modified with respect to the undoped material.

Crystal structure of chlorodimethyl(2-aminoethanethiolato)tin(IV), (NH2CH2CH2S)SnCl(CH3)2

C4H12ClNSSn, orthorhombic, Pbca (no. 61), a = 11.422(2) Å, b = 11.475(2) Å, c = 13.582(2) Å, V = 1780.2 Å3, Z = 8, Rgt(F) = 0.057, wRref(F2) = 0.147, T = 293 K.

Synthesis, characterization and in vitro cytotoxicity of new organotin(IV) derivatives of N-methylglycine

The synthesis and characterization of new coordination compounds of some diorganotins(IV) with N-methylglycine (sarcosine) are reported; all these derivatives mainly tend to assume a chelate structure. As single crystals were not obtained, a large number of experimental techniques were used to accomplish a definitive characterization and determination of their structure. Results obtained by (1)H/(119)Sn NMR, FT-IR and (119)mSn-Mössbauer spectroscopy and thermogravimetric analysis allow us to deduce the pentacoordination for 1:1 (Sn/sarcosine) derivatives [R(2)SnCl(2)(Sar)](+)Cl(-) (R=Me, n-Bu) in a trigonal-bipyramidal structure, and the hexacoordination for 1:2 complexes [R'(2)Sn(Sar)(2)](2+)2Cl(-) (R'=Me, n-Bu, Ph) in an octahedral structure; however, the probability of partially or totally non-chelate structures for some adducts increases with the steric hindrance of the R/R' groups and the number of the sarcosine molecules bound to the tin atom, so that they give rise to fluxional equilibria in solution. Finally, the synthesized compounds have been tested for in vitro cytotoxic activity against human adenocarcinoma HeLa cells showing, in some cases, strong activity even at low concentration.