A search for multidrug resistance modulators: the effects of retinoids in human colon carcinoma cells

The development of multidrug resistance (MDR) is one of the major causes of failure in cancer therapy. The use of cell lines with acquired resistance to anticancer agents represents a very good tool for investigation into the possibility of reversal of MDR. In this study the ability of all-trans-retinoic acid (RA) and its derivative 6-OH-11-O-hydroxyphenanthrene (IIF; pat. WIPO W000 /117143) as antitumor agents was investigated in the human colon carcinoma cell line LoVo and in the counterpart resistant derivative LoVo/MDR cell line. Cell proliferation was measured by MTT assay, apoptosis was evaluated using DNA fragmentation and Annexin V detection assay. Retinoids suppressed cell proliferation in a time- and dose-dependent manner. Interestingly, IIF was significantly more effective than RA, particularly on LoVo/MDR cells. RA and IIF induced apoptosis in both cell lines, with IIF effect significantly higher than that of RA. Furthermore, on the basis that MDR phenotype is often caused by drug efflux due to overexpression of the membrane P-glycoprotein (P-gp), it was demonstrated that RA and IIF reduced P-gp synthesis in LoVo/MDR cells. Our results suggest that IIF could be a powerful tool in the development of colon carcinoma treatments, even when tumor cells present an MDR phenotype.

[Chronic gastrointestinal bleeding]

Chronic gastrointestinal bleeding can occur as recurrent overt blood loss (hematochezia, melena or hematemesis) or as occult gastrointestinal bleeding. Occult bleeding from the gastrointestinal tract is typically identified by either a positive stool test for occult blood or by the presence of iron deficiency anemia. The major cause of iron deficiency anemia is blood loss from the gastrointestinal tract. In women, menstrual blood loss must also be considered. Approximately 5% of all patients with gastrointestinal bleeding do not have lesions identified by upper or lower endoscopy. In most of these patients, the bleeding source responsible for the chronic blood loss is located in the small bowel. The most common cause for gastrointestinal bleeding of small bowel origin is angiodysplasia, tumors of the small intestine (primary benign or malignant tumors or metastatic lesions) and various other causes (such as ulcers caused by nonsteroidal antiinflammatory drugs, aortoenteric fistula, diverticula, endometriosis and hemobilia). After negative upper and lower endoscopy, examination of the small bowel is warranted. Methods to evaluate the small bowel include enteroscopy, capsule endoscopy, small bowel radiographic studies and angiography. The role of each examination depends upon the clinical setting and available expertise. Explorative surgery with intraoperative enteroscopy is generally reserved for patients with ongoing transfusion requirement and in those under the age of 5O years (to rule out a small bowel neoplasm). This article reviews the concepts of evaluation and care of patients with chronic gastrointestinal bleeding.

[Prevalence of risk factors for ischemic heart disease in a northern Italian adult population]

The aim of this study is to measure the prevalence of cardiovascular risk factors in Tavazzano (Lodi) inhabitants, in order to implement efficacious and preventive strategies at community level. In 1998 the target population consisted of 2055 adults (males and females) aged 35-64, living in Tavazzano (Lodi province). The examined population was made of 856 subjects (399 males and 457 females), with a participation rate equal to 41,6%. A questionnaire concerning medical history and life habits such as: smoking, alcohol consumption and physical activity was administered to each participant. Height, Weight, Systolic and Diastolic Blood Pressure, Fasting Blood Glucose, Total Cholesterol and triglycerides were collected. A 12-leads electrocardiogram, evaluated both with standard clinical criteria and Minnesota Code, was done for each subject. The results show a high prevalence of modifiable cardiovascular risk factors: hypertension (25,2%), smoking (26,1%), obesity (14,6%), hypercholesterolemia (27,5%), low physical activity (39,6%) mainly in males and with an increasing trend with age. These data indicate the need of preventive programmes addressed to the general population and to "subjects at risk", according to the National Health Plan 2003-2005.

Comparison of incidence of sepsis in cancer patients that underwent systemic or loco-regional chemotherapy

In this retrospective non controlled trial we evaluated the incidence of sepsis in cancer patients in two different periods (January-June 2003 versus January-June 2004). The main difference in these two periods was that in our oncology department we changed from systemic chemotherapy to loco-regional chemotherapy using less myelosuppressive drugs and developed the domiciliary assistance. The aim of the study was to assess the incidence of sepsis in order to demonstrate a reduction of the infection related to the change of chemotherapy. In addition, this study may be able to describe the epidemiology of sepsis in cancer patients afferent to our oncology department. The incidence of sepsis was reduced in the second period from 24.3% to 6.2%. The pathogens more frequently isolated in this study were coagulase-negative staphylococci (CNS) followed by Escherichia coli and Staphylococcus aureus. Less invasive therapy may reduce infective complication of chemotherapy. The epidemiology of sepsis may be very helpful to design empiric therapeutic protocol for febrile patients that have received chemotherapy.

Oxidation of milled wood lignin with laccase, tyrosinase and horseradish peroxidase

In this paper the oxidation of milled wood lignin (MWL), catalysed by three enzymes, i.e. laccase, tyrosinase and horseradish peroxidase (HRP) was studied. The oxidation was followed by measuring the consumption of O(2) during laccase and tyrosinase treatment and of H(2)O(2) during HRP treatment. Both laccase and HRP were found to oxidise lignin effectively, whereas the effect of tyrosinase was negligible. The changes in MWL molecular-weight distributions caused in the reactions were analysed by gel permeation chromatography. Both laccase and HRP treatments were found to polymerise MWL. Peroxidase treatment was found to decrease the amount of phenolic hydroxyls in MWL, whereas no such effect could be detected in the laccase-treated sample. Both laccase and HRP treatments were, however, found to increase the amount of conjugated structures in MWL. The formation of phenoxy radicals during the treatments was studied by electron paramagnetic resonance spectroscopy. Phenoxy radicals were detected in both laccase and HRP-treated samples. The amount of the formed phenoxy radicals was found to be essentially constant during the detected time (i.e. 20-120 min after the addition of enzyme).

Retinoids and cancer: antitumor effect of ATRA and of a new derivative of retinoic acid, IIF, on colon carcinoma cell lines CaCo-2 and HT-29

Vitamin A and its metabolic forms, like all-trans retinoic acid (ATRA), are used with promising results in the treatment of many tumors. Two major problems in the clinical use of retinoids are that the doses needed for successful treatment are often toxic, leading to "hypervitaminosis A syndrome" and that patients often develop drug resistance. In order to find compounds that can overcome these problems, many new derivatives of retinoids have been synthesized and tested. Here we present a study on the effect of a new derivative of retinoic acid, IIF (pat. WIPO W0 00/17143), on growth and differentiation of two colon carcinomna cell lines, CaCo-2 and HT-29, with different degrees of tumorigenicity, the second one being more undifferentiated. The effect of IIF was compared with that of ATRA, whose antitumoral action on colon cancer cells and other tumoral cells is widely described in the literature. Besides exerting a strong antiproliferative effect, even higher than that of ATRA, IIF induced cellular differentiation, as demonstrated by the appearance of morphological (domes and microvilli formation) and biochemical (alkaline phosphatase induction) markers. Therefore, these findings indicate the new retinoid IIF as a possible candidate in the treatment of colon cancer.

Retinoids and cancer: antitumoral effects of ATRA, 9-cis RA and the new retinoid IIF on the HL-60 leukemic cell line

OBJECTIVE

To compare the antitumoral effects of all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA) with those of 5-OH,11-O-hydrophenanthrene (IIF), a new derivative of retinoic acid.

MATERIALS AND METHODS

The effect of retinoids was tested on cell line HL-60. Cell differentiation and apoptosis were evaluated by morphological and biochemical analysis as BCL-2 protein and by DNA fragmentation assay. The ability to activate retinoic acid receptors (RAR) and/or retinoid X receptors (RXR) and to modulate gene expression was determined by transactivation assay.

RESULTS

With cell line HL-60, the antiproliferative effect of IIF was stronger than that of ATRA and 9-cis RA. Following retinoid treatment, cells appeared to differentiate and apoptotic cells were observed. The appearance of DNA laddering and a decrease in the amount of BCL-2 protein confirmed apoptosis. IIF transcriptionally activated RXR-gamma more than RAR-alpha.

CONCLUSION

The findings indicate that IIF transcriptionally activates RXR-gamma preferentially, induces apoptosis and has a more antiproliferative activity than ATRA and 9-cis RA on cell line HL-60.

Effect of a new derivative of retinoic acid on proliferation and differentiation in human neuroblastoma cells

Neuroblastoma, a tumor originating from the sympathetic nervous system, is the most common extracranial malignant solid tumor of childhood. Human neuroblastoma cells may differentiate in vitro under treatment with a variety of biological agents and drugs. Among these, retinoic acid (RA) is quite potent and its effectiveness as a therapeutic agent is now being evaluated in clinical trials. As its pleiotropic biological activities may produce side-effects limiting clinical use, it is important to find new compounds that present the same effectiveness together with few side-effects. In this study we have explored the action of IIF, (pat. WIPO W0 00/17143) a new derivative of RA, as a differentiation inducer in the human neuroblastoma cell line TS12. In the same cell line, we have also compared the effect of IIF with that of all trans RA (ATRA) and of 9 cis RA (9cRA), with respect to morphological and biochemical differentiation and growth inhibition. Treatment with IIF resulted in a strong inhibition of proliferation and in a marked induction of neuronal differentiation as revealed by neurite extension, increase of actylcholinesterase (AchE) specific activity and tyrosine hydroxylase (TH) expression. The results demonstrate the effectiveness of this new retinoid as a differentiation inducer on neuroblastoma cells TS12. Furthermore, the differentiation-promoter and antimitotic activities of IIF were on the whole more pronounced than those of ATRA and 9cRA. Therefore our study suggests the evaluation of the new retinoid IIF as a therapeutic approach in the treatment of neuroblastoma.

Anaerobic removal of linear alcohol ethoxylates

The present paper deals with a laboratory-scale study of anaerobic treatment of two commercial mixtures (LS2, LT7) of alcohol ethoxylates with 8-14 carbon atoms and 2 and 7 ethoxy groups. Tests were carried out in batch, with a 2 g l(-1) single dose, and in semibatch, with daily 0.2 g l(-1) doses. The behaviour of the tested mixtures was different: anaerobic sludge adsorption was the main removal process for LS2, while adsorption was less significant and biodegradation was more important for LT7. These differences appeared to be mainly related to the ethoxy portion length determining the extent of biodegradability and adsorption.

Gas-phase reaction of phenol with NO3

The fast gas-phase reaction of NO3 radicals with phenol was found to yield 2-nitrophenol as the only relevant nitration product. The yield of this product was high and independent of the concentration of NO2 at the concentrations applied. In the presence of ozone, also significant amounts of 4-nitrophenol and p-benzoquinone were formed. The rate constant of the reaction between NO3 radicals and phenol was determined to be 5.8 x 10(-12) cm3 molecule-1 s-1. The selective formation of 2-nitrophenol (2) is suggested to derive from either the concerted keto-enol tautomerism in the reaction of a phenoxy radical with NO2 or the concerted elimination of nitric acid from a cyclohexa-3,5-diene intermediate.

Allergenicity of mare's milk in children with cow's milk allergy

BACKGROUND

Cow's milk allergy is a common disease of infancy and early childhood. If the baby is not breast-fed, a substitute for cow's milk formula is necessary.

OBJECTIVE

The aim of this study was to investigate, in vitro and in vivo, the allergenicity of mare's milk in a population of selected children with severe IgE-mediated cow's milk allergy.

METHODS

Twenty-five children (17 male and 8 female) aged 19 to 72 months (median age 34 months) with IgE-mediated cow's milk allergy were selected for this study. All the children underwent skin prick tests with cow's milk and mare's milk and double-blind placebo-controlled oral food challenge (DBPCOFC) with fresh cow's milk, fresh mare's milk, and, as placebo, a soy formula (Isomil, Abbott, Campoverde, Italy). We performed immunoblotting of cow's and mare's milk developed with IgE from allergic children.

RESULTS

All the children showed strong positive skin test responses to cow's milk (4+); 2 children had positive skin test responses to mare's milk (2+). All children had positive DBPCOFCs to cow's milk; one child had a positive DBPCOFC to mare's milk. No children reacted to the placebo (Isomil). In the cow's milk, some proteins are able to strongly react with human IgE; when the sera are tested with mare's milk, the bands corresponding to the same proteins are recognized by a lower percentage of sera.

CONCLUSION

These data suggest that mare's milk can be regarded as a good substitute of cow's milk in most children with severe IgE-mediated cow's milk allergy. It would be prudent, however, to confirm its tolerability by a supervised titrated oral challenge test.

A 38 kDa nuclear protein is involved in the retention of an antisense oligonucleotide directed against cytosolic phospholipase A2

Recent studies suggest that antisense phosphorothioate oligonucleotides (APO) are useful tools not only to impair gene expression, but also to modify the splicing of pre-mRNA, as the classical view that they act by suppressing the translation of mature mRNA has been challenged by several examples showing their nuclear site of action. In this work we show that an APO directed against cytosolic phospholipase A2 (cPLA2) mRNA localises in the nucleus and interacts with a specific nuclear protein.

Toward an in vitro test for the diagnosis of allergy to penicillins. Synthesis, characterization, and use of beta-lactam and beta-lactam metabolite poly-L-lysines which recognize human IgE antibodies

Conjugates of poly-L-lysine (PLL) containing a penicillin or a penicilloyl residue were prepared and characterized by 1H NMR and by size-exclusion (SE) HPLC. These conjugates were used in a radio allergo sorbent tests (RAST) test for the determination of allergy toward beta-lactams. The chemiometric evaluation of the data indicates that allergy to amoxycillin is different from allergy to the other beta-lactams tested. Furthermore, careful chemical characterization of the conjugates appears to be crucial to obtain meaningful information from the RAST data.

Retroconduction selective recognition in wide-dipole floating atrial sensing. The Multicenter Study Group

Effective discrimination of retrogradely conducted P waves would allow distinguishing sinus tachycardia from supraventricular tachycardias due to AV or nodal reentry, and would prevent pacemaker-mediated tachycardia in AV sequential pacing. This might be especially relevant in VDD implants, where retroconduction could be induced by escape ventricular stimulation. In order to analyze the respective waveform properties, anterograde and retrograde atrial signals were recorded by a wide floating electrode dipole, on the implantation of a permanent single-pass lead for VDD pacing. Generally, bipolar recording did not allow reliable discrimination, while the signal nature could be readily diagnosed from the main features of the unipolar atrial electrograms. The unipolar waveform recorded under sinus rhythm in high right atrium, close to the superior vena cava opening (proximal EGM), started with a negative deflection in 88% of the patients. In 7% of the patients, the first deflection of the signal was positive in some cardiac cycles only, and, on the average, the amplitude of the positive phase was not higher than 5% of the signal peak-to-peak amplitude. Conversely, under retroconduction, the starting deflection attained higher positive values in 98% of the patients, being stably over 15% of the peak-to-peak amplitude in 86% of the Furthermore, in 69% of the cases, the lag time between the onset of the negative deflection of proximal and distal (mid-low atrium) unipolar EGM changed unambiguously when retroconduction occurred, exceeding the range of variation observed in each patient during sinus activity. The combined evaluation of unipolar EGM shape and lag time allowed specific retroconduction recognition in 95% of the patients. We suggest that this approach may yield useful information for the discrimination of retrograde atrial signals, provided that the recording dipole is sufficiently long and the proximal electrode is properly positioned in the high right atrium.

Comparison of recent trends in adolescent and adult cigarette smoking behaviour and brand preferences

OBJECTIVE

To compare trends in smoking behaviour and use of cigarette brands by adults and adolescents.

DESIGN

Data analysed in this paper come from tobacco use surveys of adults and teenagers conducted in 18 communities in the United States, as part of the National Cancer Institute's Community Intervention Trial for Smoking Cessation. Data on adult smoking behaviour were obtained from two cross-sectional telephone surveys, one conducted from January to May 1988 (n = 99348), and the second conducted between August 1993 and January 1994 (n = 79890). Data on adolescent smoking behaviour were obtained from two school-based surveys of ninth-grade students (aged 13-16 years), one conducted in autumn 1990 (n = 7097), and the second conducted in autumn 1992 (n = 7277).

OUTCOME MEASURES

Adult cigarette smoking prevalence was estimated as the percentage of adults (18+ years) who were identified either by interview or by proxy as a current smoker. Among adolescents, current smokers were defined as those who reported having smoked on one or more of the 30 days preceding the interview. Cigarette brand use by adults was measured by asking current smokers to report the six digit UPC code on the side of the pack of their current cigarettes. A master list of UPC code numbers was developed so that reported codes could be associated with specific brand names. Among adolescents, cigarette brand use was measured by asking current smokers who reported that they usually buy their own cigarettes: "What brand do you usually buy?"

RESULTS

In ninth-grade students, smoking prevalence rates increased between 1990 and 1992 in 13 of the 18 communities. Among adults, smoking rates declined between 1988 and 1993 in 17 out of 18 communities. Within the same communities, cigarette brand use was found to be much more tightly concentrated in adolescent smokers compared with adults, with teenage smokers more likely to report using the most heavily advertised cigarette brands--Marlboro, Newport, and Camel.

CONCLUSIONS

Smoking prevalence rates have increased among teenagers, but have dropped among adults in the same communities. Among adolescents who smoke, and buy their own cigarettes, the three most heavily advertised brands--Marlboro, Camel, and Newport--have a substantially higher market concentration than among adult smokers.

Tilt test results in young and elderly patients with syncope of unknown origin

The effects of aging on the results of prolonged drug-free tilt testing were studied in 175 consecutive patients with unexplained syncope divided into 3 groups: 59 patients < 40 years old; 57 patients between 40 and 60 years; and 59 patients > 60 years old. Tilt-induced vaso-vagal syncope occurred respectively in 17 (29%), 20 (35%), and 18 patients (31%) in the 3 age groups. Vasodepressor, mixed, and cardioinhibitory vaso-vagal syncope occurred similarly in the 3 groups; organic heart disease and systemic hypertension were more frequent in elderly patients without affecting the incidence of tilt-induced syncope. Blood pressure and heart rate variations during syncope were similar in the 3 age groups; in the first 20 minutes of tilt testing, before the appearance of the vaso-vagal reflex, elderly patients showed greater reduction in blood pressure and smaller increase in heart rate than younger patients. Our data indicate that increasing age determines a different blood pressure and heart rate behavior during tilt testing, but apparently does not influence the incidence of vaso-vagal syncope in patients with syncope of undetermined etiology. As the proportion of patients with a positive isoproterenol tilt test was reported to decline with age, our results suggest that the reduced incidence of syncope during isoproterenol tilt testing could be the expression of impaired autonomic response among elderly syncope patients.

Daily fluctuations of haematology and blood biochemistry in horses fed varying levels of protein

Changes in the plasma biochemistry of 12 stallions were studied over seven 24 h periods. Twelve healthy male horses of 4 different breeds (Thoroughbred [TB], Anglo-Arabo-Sardo [AAS], Avelignese [Av] and Maremmano [M]) were divided into 3 experimental groups and fed with an isoenergetic maintenance ration with different protein levels. The same amount of food was given daily at 0730 and 1930 h. After 20 days of pretrial, a series of 6 blood samples were collected daily from the jugular vein every 4 h for 7 days. The samples were analysed for packed cell volume (PCV), haemoglobin, plasma glucose, free fatty acids, cholesterol, total plasma protein, urea, creatinine, calcium, phosphorus and enzymatic activities: aspartate aminotransferase (AST), alanine aminotrasferase (ALT), creatine kinase (CK) and lactate dehydrogenase (LDH). The data were analysed following the armonic analysis (Fourier) in order to define the pattern of biorhythm. Many parameters showed a biorhythmical pattern. Protein levels of the diet failed to influence haematology, blood biochemistry and biorhythm. Thoroughbreds showed the highest values of PCV, haemoglobin and creatinine and the lowest total protein, phosphorus and enzymatic activities.