New derivatives of xanthenone-4-acetic acid: synthesis, pharmacological profile and effect on TNF-alpha and NO production by human immune cells

New derivatives of xanthenone-4-acetic acid, bearing an alkoxy chain of variable length and a basic moiety, were synthesised in order to test the influence of this additional function on antitumour activity. The introduction of bulky substituents carrying a basic nitrogen seems to be somewhat tolerated, since for some of the compounds the enhancement of lytic potential of human monocytes was comparable to that of the reference molecule DMXAA. The induction of the release of TNF-alpha and nitric oxide by human monocytes, as well as the hypothesis of a potentiation of the activity of lipopolysaccharide in the induction of those cytotoxic factors, was also evaluated. In this respect, the most interesting compound (6a) exhibited the same spectrum of biological activity shown by DMXAA and seems therefore to be endowed with the same mechanism of action of the reference compound.

Dose imaging with gel-dosemeter layers: optical analysis and dedicated software

In radiotherapy involving thermal and epithermal neutrons, the knowledge of dose distributions, with separation of the contribution of each secondary radiation component, is of utmost importance. Layers of Fricke-Xylenol-Orange-infused gel dosemeters give the possibility of achieving such requirements because, owing to the layer-geometry, enriching or depleting the gel matrix of suitable isotopes does not sensibly alter neutron transport. The dosimetry method has been critically re-examined with the aim of improving its suitability to boron neutron capture therapy (BNCT) requirements, as it applies to the protocol of measurement and analysis, the sensitivity of the method and the range of the linearity of the dosemeters. Software has been developed and studied to obtain automatically the images of the various dose components with the established separation procedure.

One-year longitudinal study of young apprentices exposed to airway occupational sensitizers

BACKGROUND

The prevalence of diagnosed asthma and wheezing in young subjects is increasing; among environmental risk factors, occupational exposure can play a relevant role.

STUDY OBJECTIVES

The purpose of the study was to evaluate the effects of occupational exposure to a large variety of irritants and/or sensitizers on the incidence of respiratory symptoms and pulmonary function impairment in a group of young apprentices during the first year of work exposure, and to determine the prevalence of asthma-like symptoms and the role of different risk factors (gender, smoking habit, atopy and occupational exposure) in this young population.

DESIGN AND METHODS

We studied 448 young apprentices at the first pre-employment evaluation with a standardized questionnaire, spirometry and skin prick tests; in 244 of them clinical and functional evaluation was repeated after 1 year exposure to respiratory irritants or sensitizers.

RESULTS

At the first examination, males had higher prevalence of attacks of shortness of breath with wheeze, diagnosis of asthma, smoking habit and atopy than females. At the second examination there was no significant increase in the prevalence of respiratory symptoms. However, incident cases for cough, phlegm, wheezing, shortness of breath with wheeze (SOBWHZ) and asthma were all higher than remittent cases. Incidence of respiratory symptoms was associated with atopy and smoking habit.

CONCLUSIONS

Respiratory symptoms slightly increase over 1 year occupational exposure to sensitizers or irritants. The loss at the follow-up of subjects with higher smoking habit suggests a small "health worker effect" and could underestimate the effect of occupational exposure in apprentices.

How to identify and calculate glenoid bone deficit

In recent years, we have seen increased interest in bone lesions of the glenoid rim as acute fractures (Bony-Bankart) and as chronic bone defect in instability. This derives from three main clinical and statistical findings: a significant incidence of bony Bankart lesion after a first dislocation, a high percentage of glenoid bone defects in chronic instability, and, finally, a close relationship between bone defect and incidence of recurrence after arthroscopic stabilization. The authors agree on determining glenoid bone defect that exceeds 15-20% as the main contraindication to arthroscopic stabilization. It is thus necessary to accurately calculate bone defect in order to be able to plan the most suited type of surgery. The authors report their simple, accurate and reproducible CT method known as Pico to quantify and measure bone defect in terms of percentage bone area and in terms of square mm of defect.

Mono- or di-fluorinated analogues of flavone-8-acetic acid: synthesis and in vitro biological activity

BACKGROUND

Previously, the antitumour activity of some flavone-8-acetic acid (FAA) derivatives substituted with an acid function in position 2 of the benzene ring was evaluated. The most active compound resulted the one bearing a fluorine atom in position 7 of the flavone nucleus. In this paper, we evaluated new mono- or di-fluorinated FAA derivatives.

MATERIALS AND METHODS

The cytotoxicity towards two human ovarian adenocarcinoma cell lines, the capability to stimulate human mononuclear cells and murine macrophages' lytic properties were evaluated by MTT. Moreover, the potentiation of lipopolysaccharide (LPS) activity was studied by ELISA analysis of TNF-alpha release.

RESULTS

The analogues showed a direct cytotoxicity comparable to that of 5,6-dimethyl-xanthen-9-one-4-acetic acid (DMXAA), at present in clinical trials. None of the tested compounds was able to stimulate human mononuclear cells' lytic properties after either 4- or 24-h treatment, while after 4-h treatment, the derivative 5a was more able to stimulate murine macrophages with respect to DMXAA. Moreover, a significant increase of 5c and 5d activation was obtained with LPS association, reflected by TNF-alpha production as well.

CONCLUSION

Like FAA, the new fluorinated derivatives 5a, 5c and 5d showed remarkable activity in murine cells, but this was not confirmed in human models.

Homopterocarpanes as bridged triarylethylene analogues: synthesis and antagonistic effects in human MCF-7 breast cancer cells

A series of new compounds structurally derived from 6a,12a-dihydro-6H,7H-[1]-benzopyran-[4,3-b]-benzopyran (homopterocarpane) was efficiently synthesized by reduction of the corresponding pyrilium salts obtained by treatment of selected flavanones and aldehydes with anhydrous HClO4. Cytotoxic effects on the human breast cancer cell line MCF-7 and antiestrogenic activity (only for compounds which resulted more active than tamoxifen (TAM)) on MCF-7 cells stimulated by 17beta-estradiol were evaluated. In vivo antiestrogenic activity and the relative binding affinity were also assessed. Some of the new compounds (4c, 4h, 4i and 4l) showed a biological activity in the micromolar range, and were more potent than TAM taken as the reference.

Anti-inflammatory effect of mud-bath applications on adjuvant arthritis in rats

OBJECTIVE

The real effects of mud-bath applications on the inflammatory process are still not clarified. We studied these effects on rat adjuvant-induced arthritis.

METHODS

Arthritis was induced in 30 rats by subplantar injection of Freund's complete adjuvant (FCA) into the right hind paw. Ten days after FCA injection, the rats were randomized in 3 groups of 10 each: the first one was submitted to a cycle of mud-bath applications, the second one was treated with indomethacin, the third one received only saline per os (control group). The paw volume, measured by plethysmometry, and the serum levels of TNFalpha and IL-1beta were considered as evaluation parameters.

RESULTS

FCA injection caused a progressive enhancement of paw volume and a rapid increase of TNFalpha and IL-1beta serum levels. After the randomization, mud-bath applications reduced inflammation and at the end of the treatment the paw volume and the TNFa and IL-1beta serum levels were significantly tapered in comparison to the controls (p < 0.01).

CONCLUSION

The results of the study suggest an anti-inflammatory effect of mud-bath applications on adjuvant arthritis in rats. These results could explain the beneficial effects of thermal treatments observed in some inflammatory rheumatic diseases.

Levocloperastine in the treatment of chronic nonproductive cough: comparative efficacy versus standard antitussive agents

The medical and social impact of cough is substantial. Current antitussive agents at effective doses have adverse events such as drowsiness, nausea and constipation that limit their use. There is also recent evidence that standard antitussive agents, such as codeine, may not reduce cough during upper respiratory infections. Therefore, there is a need for more effective and better-tolerated agents. The efficacy of levocloperastine, a novel antitussive, which acts both centrally on the cough center and on peripheral receptors in the tracheobronchial tree in treating chronic cough, was compared with that of other standard antitussive agents (codeine, levodropropizine and DL-cloperastine) in six open clinical trials. The studies enrolled patients of all ages with cough associated with various respiratory disorders including bronchitis, asthma, pneumonia and chronic obstructive pulmonary disease. Levocloperastine significantly improved cough symptoms (intensity and frequency of cough) in all trials, and improvements were observed after the first day of treatment. In children, levocloperastine reduced nighttime awakenings and irritability, and in adults it was effective in treating cough induced by angiotensin-converting enzyme inhibitors. When compared with other antitussive agents, levocloperastine had improved or comparable efficacy, with a more rapid onset of action. Importantly, no evidence of central adverse events was recorded with levocloperastine, whereas drowsiness was reported by a significant number of patients receiving codeine. Levocloperastine is an effective antitussive agent for the treatment of cough in patients of all ages. It has a more rapid onset of action than standard agents with an improved tolerability profile.

Synthesis and biological evaluation of 3-alkoxy analogues of flavone-8-acetic acid

New analogues of flavone-8-acetic acid were synthesized, bearing an alkoxy group in position 3 and different substituents on the benzene ring in position 2 of the flavone nucleus. The compounds were tested for direct cytotoxicity against four human tumor cell lines and for indirect antitumor effects by measuring their ability to enhance lytic properties of murine macrophages and human monocytes. Though direct toxicity was very low, the compounds were able to induce significant indirect toxicity. Notably, most of them (4c, 4d, 4e, 4f, 4h, 4i, 4m,4n, and 4o) showed important activity on human monocytes and could be regarded as the first flavone derivatives endowed with such activity. Particularly interesting seem to be compounds 4m and 4n, which showed IC(50) values up to 7 times higher than DMXAA, which has now completed phase I clinical trials.

Risk factors for chronic respiratory disorders in a sample of farmers in middle Italy

OBJECTIVE

To evaluate the prevalence of respiratory symptoms in agricultural workers in a rural area of Tuscany and to relate them to some occupational risk factors.

SUBJECTS AND METHODS

A cross sectional study was performed on a sample of 461 agricultural workers from two rural area of Tuscany. All subjects underwent to respiratory questionnaire, pulmonary function test and skin prick tests. Occupational risk factors were evaluated as response to questions related to 11 specific jobs, most of them related to cow-shed works.

RESULTS

Subjects had high mean age and a long work duration. Smoking habit was significantly associated with symptoms of chronic bronchitis, while atopy was significantly associated with chronic cough, phlegm and dyspnea. In comparison with a control group of workers which did not report any occupational risk factors (reference group), logistic analysis showed that most symptoms were significantly associated with some specific jobs related to animal breeding, taking into account differences due to age, smoking habit, atopy and district. Mean pulmonary function tests were in the normal range, without any significant relationship with different risk factors, except smoking habit. Increased work duration was associated with significant decrease of pulmonary function.

CONCLUSION

Symptoms of chronic bronchitis were frequent in this population of farmers of Middle Italy. The analysis of risk factors confirms a relevant role for some specific occupational risk factors, related to jobs in the cow-shed, in the development of respiratory disorders.

Synthesis and antitumor activity of new derivatives of xanthen-9-one-4-acetic acid

Xanthen-9-one-4-acetic acid (XAA) analogues in which the substituents in positions 5 and 6 are included in cyclic structures are described. Direct in vitro toxicity of the synthesized compounds against four tumor cell lines was evaluated, and their ability to stimulate mouse peritoneal macrophages and human monocytes in culture to become tumoricidal (indirect toxicity) was also studied. Despite low direct toxicity, almost all the compounds proved to be able to significantly enhance the lytic properties of both murine macrophages and human monocytes as well as the parent compound XAA and its most active derivative DMXAA taken as reference. In particular, compounds 4a, 5a, 7a, 13a,b, and 16a,b showed higher activity than the lead compound on human monocytes, compound 7a being 2.5 times more active than DMXAA, which is the most potent compound synthesized so far. Moreover, compounds 4a, 5a, 7a, 13a, 16a, and 16b proved to be able to induce TNF production in human immune cells.

Cytotoxicity of paclitaxel in combination with cisplatin and a new Pt-mercaptopyridine complex

In vitro synergy has been reported for exposure to paclitaxel prior to cis-platin (cis-DDP), whereas the reverse sequence resulted in antagonism. There is no clear evidence for an intracellular origin of the schedule-dependent interaction, but several hypotheses have been proposed, such as effects at the level of DNA crosslinks, or binding to tubulin sites. The purpose of this study was to evaluate the cytotoxicity of these two drugs as single agents, in combination and in sequence, against a human colon adenocarcinoma cell line (LoVo). Moreover, we considered the new Pt-mercaptopyridine complex C/2, was like cis-platin in being able to alter DNA conformation. We have therefore studied the cytotoxic effects after single agent exposure, concomitant exposure (paclitaxel + cis-platin and paclitaxel + C/2) and sequential drugs exposure (paclitaxel-->cis-platin and cis-platin-->paclitaxel or paclitaxel-->C/2 and C/2-->paclitaxel). Our results demonstrate that the most cytotoxic effect is induced by paclitaxel and C/2 exposure both in the case of concomitant cell treatment and sequential exposure paclitaxel-->C/2.

High-fiber diet supplementation in patients with irritable bowel syndrome (IBS): a multicenter, randomized, open trial comparison between wheat bran diet and partially hydrolyzed guar gum (PHGG)

High-fiber diet supplementation is commonly used in IBS, although it poses several management problems. Partially hydrolyzed guar gum (PHGG) has shown beneficial effects in animal and human studies, but its potential role in IBS symptom relief has not been evaluated yet. We investigated PHGG in IBS patients and compared it to a wheat bran diet. Abdominal pain, bowel habits, and subjective overall rating were longitudinally evaluated in 188 adult IBS patients (139 women and 49 men) for 12 weeks. Patients were classified as having diarrhea-predominant, constipation-predominant, or changeable bowel habits and were randomly assigned to groups receiving fiber (30 g/day of wheat bran) or PHGG (5 g/day). After four weeks, patients were allowed to switch group, depending on their subjective evaluation of their symptoms. Significantly more patients switched from fiber to PHGG (49.9%) than from PHGG to fiber (10.9%) at four weeks. Per protocol analysis showed that both fiber and PHGG were effective in improving pain and bowel habits, but no difference was found between the two groups. Conversely, intention-to-treat analysis showed a significantly greater success in the PHGG group (60%) than in the fiber group (40%). Moreover, significantly more patients in the PHGG group reported a greater subjective improvement than those in the Fiber group. In conclusion, improvements in core IBS symptoms (abdominal pain and bowel habits) were observed with both bran and PHGG, but the latter was better tolerated and preferred by patients, revealing a higher probability of success than bran and a lower probability of patients abandoning the prescribed regimen, suggesting that it can increase the benefits deriving from fiber intake in IBS, making it a valid option to consider for high-fiber diet supplementation.

Diagnosis of flour-induced occupational asthma in a cross-sectional study

The diagnosis of occupational asthma is usually performed in epidemiology using a combination of symptoms and bronchial hyperresponsiveness, while in a clinical setting the 'gold standard' for the diagnosis of occupational asthma is the specific bronchial challenge test in the laboratory The aim of this study was to detect new cases of flour-induced occupational asthma (OA) in a group of workers exposed to grain and/or flour dust, by means of a step-by-step approach, as used in a clinical setting. In an epidemiological study, III millers and 186 bakers were examined by means of questionnaire, pulmonary function tests and skin-prick tests (SPT) to common allergens and to wheat flour dust extracts. From the whole sample, 82 subjects who showed asthma-like symptoms in the questionnaire and/or low forced expiratory volume in 1 sec (FEV1) were selected. Selected subjects underwent methacholine challenge test, and hyperreactive subjects underwent specific bronchial challenge with flour dust in the laboratory. Sixty-two of the selected subjects performed the methacholine challenge test, and 22 (33 8%) were hyperreactive (PD20 FEV1 <1 mg of methacholine). Fifteen of 22 hyperreactive subjects underwent specific bronchial challenge test (s BCT) with flour dust; a positive response was elicited in six subjects. These subjects can be diagnosed as having flour-induced occupational asthma. Atopy and skin sensitivity to flour was partially related to the response to flour bronchial challenge. Bronchial hyperreactivity can be observed in a small percentage of subjects with asthma-like symptoms and/or low FEV1, and a positive response to s BCTwas observed in a subgroup of hyperreactive subjects.Therefore, using these selection criteria, a diagnosis of flour-induced OA, as commonly performed in a clinical setting, can be performed in few previously undiagnosed subjects.This approach could be relevant for an early diagnosis ofoccupational asthma.

Molecular structure and cytotoxicity of 3D-transition metal complexes capable to form a stable metal-nitrogen bond

The cytotoxicity of several Co(II), Ni(II), Cu(II) and Zn(II) complexes with various molecular structures and geometries, has been tested on LoVo and 2008 cells at 1-100 microM concentration for 24 h exposure. On the basis of 24 h results, the exposure time was prolonged to 48 and to 72 hours. The most potent complexes result [Cu(tren)(H2O)]2+ 2Cl-, E, [CoCl3(H2Meppz)], G, and [CoCl3(HMe2ppz)], H, (tren=tris(2-aminoethyl)amine, H2Meppz=1-methylpiperazin-1-ium, HMe2ppz=1,4-dimethylpiperazin-1-ium cations). Nevertheless, these complexes are able to induce cell growth reduction of about 50% at highest doses tested (1-100 microM ) and after 72 h exposure.

Synthesis and biological activity of some rigid analogues of flavone-8-acetic acid

Some rigid analogues of flavone-8-acetic acid are described. Direct in vitro toxicity of the synthesised compounds was evaluated towards four tumoral cell lines and the ability of these compounds to stimulate mouse peritoneal macrophages in culture to become tumoricidal (indirect toxicity) was also studied. All compounds were able to induce direct cytotoxicity only at very high concentrations but showed a remarkable indirect activity. In particular compound 4d was able to significantly increase macrophage lytic properties and has been selected for further investigations.

Cholesterylphosphoserine as inhibitor of cell adhesion and actin polymerization in human T cells

To further investigate the immunosuppressive activity of cholesterylphosphoserine (CPHS), we examined a variety of human T cell responses including proliferation, adhesion and cytoskeletal organization. The CPHS-induced inhibition of T cell response is greater in the integrin-dependent mixed lymphocyte reaction than in the integrin-independent proliferation elicited by anti-TCR-CD3 or anti-CD28 antibodies in the presence of tetradecanoylphorbol acetate. Consistently, CPHS inhibits the homotypic T cell adhesion involving the integrin alphaLbeta2 (LFA-1) and the cell adhesion to fibronectin and rVCAM-1 involving the integrins of the beta1 family. Since CPHS does not change integrin expression but inhibits post-receptor events such as cell spreading and pseudopodal projections, it seems likely that the site of CPHS influence is distal to the adhesion receptors. In agreement, the steroid prevents the reorganization of actin cytoskeleton occurring when T cells are allowed to spread on immobilized anti-CD3 in the absence of integrin activation. We suggest that CPHS acts on the metabolic pathway in which signals from integrin and growth factor receptors converge to induce the reorganization of the actin cytoskeleton. Selectivity in the action of CPHS is indicated by its ineffectiveness in the integrin-mediated adhesion of the monocytic cell line U-937 to fibronectin.

A comparison of the modulation of antiblastics cytotoxicity by verapamil and dipyridamole in a human colon carcinoma cell line

This study was designed to compare the activity of two MDR modulators, verapamil and dipyridamole, on the in vitro growth of a human colon carcinoma cell line. The aims were: a) to investigate the different sensitivity of the parental cell line (LoVo S) and the doxorubicin-resistant one (LoVo R) towards the treatment with several antiblastics and their associations with verapamil or dipyridamole; b) to evaluate if the combined use of these drugs with verapamil or dipyridamole increases their cytotoxicity; c) to understand whether the mechanism of action of each modulator is the same. Idarubicin and vinblastine were the most active drugs on both cell lines. LoVo R cells showed cross-resistance to vinblastine, teniposide and mitoxantrone, while chemosensitivity towards cisplatin and cyclophosphamide was almost the same in both cell lines. The inhibitory effect on cell growth was enhanced when the drugs were associated with verapamil, but no difference was detected with cisplatin and cyclophosphamide. Verapamil is thus an effective MDR modulator when used with drugs actively pumped out of tumour cells by P-glycoprotein, while it is ineffective with drugs that induce resistance by different mechanisms. When combined with dipyridamole, a significant result was observed in the case of cisplatin, where a marked increase of cytotoxicity was detected.

Ion-binding and pharmacological properties of Tyr6 and Tyr9 antamanide analogs

In order to investigate the antiproliferative properties of antamanide, we have synthesized and studied two antamanide analogs where the phenylalanine residue in positions 6 or 9 is substituted by tyrosine, their corresponding linear forms and the cyclic and linear des Phe5,Phe6-Tyr9-analogs. Antamanide and its biologically active synthetic analogs are able to form highly stable complexes with metal ions, particularly Na+, K+ and Ca2+. We studied the ion-binding properties of the Tyr-antamanide analogs by CD and Tb3+ -mediated fluorescence in acetonitrile. In this medium the far-and near-UV CD spectra of the neat Tyr6-antamanide analog are very similar to that of the parent cyclic decapeptide. Substantial differences occur on the contrary in the CD spectra of the neat Tyr9-antamanide, particularly in the regions at 220 nm and 270-290 nm. In acetonitrile, as already found for antamanide, the interaction with the above-mentioned metal ions always produces evident changes in the far- and near-UV CD spectra of both analogs. On the contrary, the CD spectra of the linear deca- and octa- and of the cyclic octa-analogs are affected by the presence of metal ions only in the near-UV region. In the same solvent the Tb3+ -mediated fluorescence spectra of all the synthetic peptides are remarkably affected by the addition of ions. On the basis of the spectral total changes, by using either or both the spectroscopic techniques, it has been possible to determine the ion binding constants for all the linear and cyclic Tyr-antamanide analogs and to compare them with that of the parent peptide. The antitoxic and antiproliferative activities of these antamanide analogs have been tentatively correlated to their ion-binding properties. A preliminary account of this work was given in (1).

Synthesis of flavone-2'-carboxylic acid analogues as potential antitumor agents

Some flavone-2'-carboxylic acid analogues are described. Direct in vitro toxicity of the synthesized compounds was evaluated towards four tumoral cell lines, and the ability of these compounds to stimulate mouse peritoneal macrophages in culture to become tumoricidal (indirect toxicity) was also studied. Direct cytotoxic activity was very low for all derivatives. However, almost all compounds showed a remarkable increase of indirect cytotoxicity. In particular, compound 3i, which has an F atom in the 7 position of the flavone ring, was able to increase significantly the macrophage's lytic properties, and has been selected for further investigations.