Evaluation of cytotoxic activity of Schisandra chinensis lignans

Using exhaustive chromatographic separation we have isolated (-)-tigloyl-deangeloyl-gomisin F as a novel dibenzocyclooctadiene lignan from schisandra chinensis. With the help of HPLC, we further isolated (+)-schisandrin, (+)-deoxyschisandrin, (+)-γ-schisandrin, (-)-gomisin J, (+)-gomisin A, (-)-gomisin N, (-)-tigloyl-gomisin P, (-)-wuweizisu C, (-)-gomisin D, rubrisandrin A, (-)-gomisin G, (+)-gomisin K (3) and (-)-schisantherin C. A full NMR description of (-)-schisantherin C was carried out with the aim to confirm previous reports of its structure. Compounds isolated were identified on the basis of UV, IR, (1)H- and (13)C-NMR and MS. The cytotoxicity of lignans was tested for the BY-2 cell line alone and as a synergistic effect with the cytotoxic agent camptothecin. Lignans showed various toxicity and synergistic and antagonistic effects on camptothecin-induced cytotoxicity. Cytotoxicity against colon cancer cell line LoVo was also tested.

Polymer gels for in-phantom dose imaging in radiotherapy

Normoxic polymer gel dosimeters are studied, with the aim of achieving a valid and advantageous method for in-phantom 3D dose determinations. Developments were carried out in the application of such dosimetric material to the method based on dosimeter gel layers that has shown good reliability for absorbed dose imaging in radiotherapy. The technique has been improved, in particular taking care of minimizing the oxygen infiltration into the gel matrix in order to suitably avoid its effect of inhibiting the polymerization process after exposure. A suitable choice of the material of dosimeter walls has brought to achieve good steadiness in time of dosimeter sensitivity and satisfactory results in dose imaging and depth-dose profiling.

Immune-modulating and anti-vascular activities of two xanthenone acetic acid analogues: A comparative study to DMXAA

In order to proliferate, solid tumours require the development and continuous expansion of an organised host-derived vascular network. The anti-vascular agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) emerged as derivative of the flavone-8-acetic acid (FAA) and xanthenone-4-acetic acid (XAA). Its anti-vascular activity is not based on direct cytotoxic effects, but is characterized by an immune-mediated component, through the activation of NF-kappaB pathway, and a direct anti-vascular action, involving the induction of endothelial cell apoptosis and changes in tumour vessel permeability. Despite promising pre-clinical results, DMXAA showed moderate anti-tumour activity in clinical trials. In this study, we compared to DMXAA the in vitro immune-modulating and the anti-vascular properties of two XAA analogues, AP/1649 and AP/1897. Their immune-stimulating activities were evaluated on a human monocyte cell line and their anti-vascular activities were studied by measuring the induction of HUVECs apoptosis and using DCE-MRI to determine tumour perfusion following drug treatment. Although the two molecules exerted an immune stimulation comparable to that produced by DMXAA, they showed reduced (AP/1649) or minimal (AP/1897) anti-vascular activity in vitro, and no anti-vascular effects in vivo. These results endorse the current theories concerning two independent actions exerted by DMXAA.

Diterpenoid Alkaloids and Phenol Glycosides from Aconitum Naviculare (Brühl) Stapf

Phytochemical investigation of the aerial parts of Aconitum naviculare, a medicinal plant used in traditional Nepalese medicine, led to the isolation and characterization of two new diterpenoid alkaloids, navirine B (1), and navirine C (2), along with (+) chellespontine (3), kaempferol-7-O-β-D-glucopyranosyl(1→3)α-L-rhamnopyranoside (4), kaempferol-7-O α-L-rhamnopyranoside,3-O-β-D-glucopyranoside (5), p-coumaric-4-O-β-D-glucopyranoside acid (6), and ferulic-4-O-β-D-glucopyranoside acid (7). The structures of the isolated compounds were elucidated on the basis of extensive analyses of 1D and 2D NMR spectra (HMQC, HMBC, COSY, ROESY) and HR-MS data. The antiproliferative activity of alkaloids 1–3 against human tumor cell lines (LoVo and 2008) was also evaluated.

Small intestine bacterial overgrowth in patients with irritable bowel syndrome

Recent investigations in patients with irritable bowel syndrome (IBS) undergoing a breath test (BT) with lactulose, have shown inconclusive results on a possible association between IBS and a small intestine bacterial overgrowth (SIBO), as well as on the effective prevalence of SIBO in IBS patients, because of different geographic areas involved and different criteria adopted for the BT positivity. The aim of this study was to estimate the prevalence of SIBO among IBS patients by means a lactulose BT. Between January 2005 and December 2006, all the patients who were sent to our Gastroenterology Unit by general practitioners (GPs) for "functional" gastrointestinal (GI) symptoms, underwent a lactulose BT for diagnosis of SIBO. The test was considered positive if the hydrogen concentrations in the expired air increased more than 20 ppm over basal values within 90 minutes. A total of 127 patients have been selected, 28 males and 99 females, aged between 17 and 76 (mean age: 41.4 years), with an IBS diagnosis based on the Roma II criteria. Fifty-five patients (43%) resulted positive to the lactulose BT. No significant difference was observed between IBS patients with (SIBO+) and without (SIBO-) an intestinal bacteria contamination. In conclusion, our results indicate that SIBO is relatively frequent in IBS patients and that execution of a lactulose BT should be encouraged in all these patients, being the only way to make correct diagnosis of SIBO and establish a valid therapeutic treatment.

The ability of coumarin-, flavanon- and flavonol-analogues of flavone acetic acid to stimulate human monocytes

Flavone acetic acid (FAA) is a semi-synthetic flavonoid characterised by potent immune-modulatory and antivascular activity on mice but not in humans. Previously, the synthesis and cytotoxic activity on a human adenocarcinoma cell line of coumarin-, flavanon- and flavonol-derivatives of FAA were described. These analogues were able to induce the reduction of lysosomal neutral red uptake at 5 x 10(-5) M concentration and some of them were more effective than FAA. Some of these derivatives were selected to investigate their ability to exert immune-modulation on a human model, by using the most potent analogue that has emerged thus far, 5,6-dimethylxanthenone-4-acetic acid (DMXAA), as a reference compound. We investigated the cytotoxicity of the selected derivatives on two human ovarian adenocarcinoma cell lines and their ability to activate the immune system by inducing lytic properties, TNF-alpha and nitric oxide in human monocytes. The immune-modulating activity was assessed by treating a cell line of human monocytes (Mono Mac 6, MM6) with FAA-derivatives alone or in association with lipopolysaccharide (LPS). None of the tested molecules showed any significant ability to directly affect tumor cell proliferation, whereas they were able to induce the lytic properties of MM6 cells. In particular, two coumarin derivatives, a and d, and the flavonol acetic acid, l, showed comparable results to DMXAA. The combination with LPS did not lead to synergistic interactions in the induction of the lytic properties of MM6, but it significantly increased the release of TNF-alpha, especially after 4 h of treatment. Instead, the maximum release of nitric oxide (NO) was detected after 24 h of treatment and after exposure to the FAA derivatives alone. Derivative a combined with LPS and analogue d alone were able to induce a higher TNF-alpha and NO release, respectively, whereas flavonol acetic acid was characterised by a strictly similar activity to DMXAA.

Overview of clinical trials in the treatment of iron deficiency with iron-acetyl-aspartylated casein

Iron therapy is necessary in a wide variety of clinical situations, and new formulations with improved tolerability and efficacy would be a welcome alternative to ferrous sulfate. A trivalent iron protein complex has been developed using an N-acetyl-aspartylated derivative of casein (Fe-ASP) for oral iron therapy. This paper provides an overview of the pharmacokinetic and clinical data on Fe-ASP use. To date, 704 paediatric and adult patients affected by iron deficiency anaemia with a wide variety of clinical histories (dietary, iron absorption defects, pregnancy, chronic or acute gastrointestinal haemorrhage) have been treated with Fe-ASP in 16 clinical trials including nine open and seven controlled trials. In healthy volunteers, Fe-ASP proved to be an efficient vehicle for providing iron with high bioavailability and more rapid and persistent increases in serum iron levels than ferritin. In open clinical trials, highly significant improvements in clinical and haematological parameters were observed after treatment with Fe-ASP in all categories of patients with iron deficiency anaemia. In controlled clinical trials, the changes in clinical and haematological profiles observed with Fe-ASP were virtually identical to those seen with iron protein succinylate (IPS), and Fe-ASP also compared well with parenteral iron gluconate. No safety considerations were raised.Fe-ASP shows high efficacy in iron-deficient anaemia treatment, and it is an extremely well tolerated iron vehicle. Fe-ASP represents a valid alternative to IPS and shows promise as a substitute for parenteral iron therapy in selected clinical situations.

Skin and cutaneous melanocytic lesion simulation in biomedical optics with multilayered phantoms

The complex inner layered structure of skin influences the photon diffusion inside the cutaneous tissues and determines the reflectance spectra formation. Phantoms are very useful tools to understand the biophysical meaning of parameters involved in light propagation through the skin. To simulate the skin reflectance spectrum, we realized a multilayered skin-like phantom and a multilayered skin phantom with a melanoma-like phantom embedded inside. Materials used were Al(2)O(3) particles, melanin of sepia officinalis and a calibrator for haematology systems dispersed in transparent silicon. Components were optically characterized with indirect techniques. Reflectance phantom spectra were compared with average values of in vivo spectra acquired on a sample of 573 voluntary subjects and 132 pigmented lesions. The phantoms' reflectance spectra agreed with those measured in vivo, mimicking the optical behaviour of the human skin. Further, the phantoms were optically stable and easily manageable, and represented a valid resource in spectra formation comprehension, in diagnostic laser applications and simulation model implementation, such as the Monte Carlo code for non-homogeneous media.

Multispectral imaging and artificial neural network: mimicking the management decision of the clinician facing pigmented skin lesions

Various instruments based on acquisition and elaboration of images of pigmented skin lesions have been developed in an attempt to in vivo establish whether a lesion is a melanoma or not. Although encouraging, the response of these instruments, e.g. epiluminescence microscopy, reflectance spectrophotometry and fluorescence imaging, cannot currently replace the well-established diagnostic procedures. However, in place of the approach to instrumentally assess the diagnosis of the lesion, recent studies suggest that instruments should rather reproduce the assessment by an expert clinician of whether a lesion has to be excised or not. The aim of this study was to evaluate the performance of a spectrophotometric system to mimic such a decision. The study involved 1794 consecutively recruited patients with 1966 doubtful cutaneous pigmented lesions excised for histopathological diagnosis and 348 patients with 1940 non-excised lesions because clinically reassuring. Images of all these lesions were acquired in vivo with a multispectral imaging system. The data set was randomly divided into a train (802 reassuring and 1003 excision-needing lesions, including 139 melanomas), a verify (464 reassuring and 439 excision-needing lesions, including 72 melanomas) and a test set (674 reassuring and 524 excision-needing lesions, including 76 melanomas). An artificial neural network (ANN(1)) was set up to perform the classification of the lesions as excision-needing or reassuring, according to the expert clinicians' decision on how to manage each examined lesion. In the independent test set, the system was able to emulate the clinicians with a sensitivity of 88% and a specificity of 80%. Of the 462 correctly classified as excision-needing lesions, 72 (95%) were melanomas. No major variations in receiver operating characteristic curves were found between the test and the train/verify sets. On the same data set, a further artificial neural network (ANN(2)) was then architected to perform classification of the lesions as melanoma or non-melanoma, according to the histological diagnosis. Having set the sensitivity in recognizing melanoma to 95%, ANN(1) resulted to be significantly better in the classification of reassuring lesions than ANN(2). This study suggests that multispectral image analysis and artificial neural networks could be used to support primary care physicians or general practitioners in identifying pigmented skin lesions that require further investigations.

Dose distributions in phantoms irradiated in thermal columns of two different nuclear reactors

In-phantom dosimetry studies have been carried out at the thermal columns of a thermal- and a fast-nuclear reactor for investigating: (a) the spatial distribution of the gamma dose and the thermal neutron fluence and (b) the accuracy at which the boron concentration should be estimated in an explanted organ of a boron neutron capture therapy patient. The phantom was a cylinder (11 cm in diameter and 12 cm in height) of tissue-equivalent gel. Dose images were acquired with gel dosemeters across the axial section of the phantom. The thermal neutron fluence rate was measured with activation foils in a few positions of this phantom. Dose and fluence rate profiles were also calculated with Monte Carlo simulations. The trend of these profiles do not show significant differences for the thermal columns considered in this work.

Gel dosimetry in the BNCT facility for extra-corporeal treatment of liver cancer at the HFR Petten

A thorough evaluation of the dose inside a specially designed and built facility for extra-corporeal treatment of liver cancer by boron neutron capture therapy (BNCT) at the High Flux Reactor (HFR) Petten (The Netherlands) is the necessary step before animal studies can start. The absorbed doses are measured by means of gel dosemeters, which help to validate the Monte Carlo simulations of the spheroidal liver holder that will contain the human liver for irradiation with an epithermal neutron beam. These dosemeters allow imaging of the dose due to gammas and to the charged particles produced by the (10)B reaction. The thermal neutron flux is extrapolated from the boron dose images and compared to that obtained by the calculations. As an additional reference, Au, Cu and Mn foil measurements are performed. All results appear consistent with the calculations and confirm that the BNCT liver facility is able to provide an almost homogeneous thermal neutron distribution in the liver, which is a requirement for a successful treatment of liver metastases.

Optical devices used for image analysis of pigmented skin lesions: a proposal for quality assurance protocol using tissue-like phantoms

Different technological tools have been developed to aid in the diagnosis of pigmented skin lesions, including cameras working with conventional RGB colour systems, epiluminescence microscopy and spectrophotometric methods using visible and near infrared wavelengths. All the different procedures should provide in an objective and reproducible fashion quantitative measurements of the colour and shape features of a given skin mole. At present, many devices have been introduced in experimental stages for clinical diagnosis, mainly used to provide to the clinicians an objective, computer-assisted second opinion. As for any diagnostic instruments, optical devices should also be subjected to a dedicated quality assurance protocol in order to evaluate the response repeatability of each device (intra-instrument agreement) and to check the accordance among the responses of different devices (inter-instrument agreement). The aim of this study was to design a quality assurance protocol for optical devices dedicated to image analysis of pigmented skin lesions and, in case, to detect cutaneous melanoma by using suitable tissue-like phantoms as standard references that enable testing of both hardware and software components. As an example, we report the results of intra-instrument and inter-instrument agreement when the protocol was applied on a series of 30 SpectroShade instruments, a novel optical device based on multi-spectral image analysis of colour and shape features of pigmented skin lesion.