Feasibility study of colorectal cancer screening by immunochemical faecal occult blood testing: results in a northern Italian community.

AIM: Screening by means of faecal occult blood testing (FOBT) has proved to be effective in reducing colorectal cancer incidence and mortality. We performed a pilot screening for colorectal cancer by latex immunological FOBT in two municipalities of the region Valle d'Aosta, Italy, focusing on problems and obtaining indications for the feasibility and extension of the screening programme on a regional basis. METHODS: A total of 2961 subjects aged 50-74 years were invited by mail to perform a one-day immunochemical FOBT without any dietary restrictions and with a positive threshold put at 100 ng/ml. Patients with positive tests were then invited to undergo colonoscopy and double-contrast barium enema if colonoscopy was incomplete. RESULTS: A total of 1631 subjects performed the screening test with an overall compliance of 55.1%. Seventy-two subjects had a positive FOBT. Detection rates for cancer and adenomas were 1.8 per thousand and 16.6 per thousand, respectively. Positive predictive values (PPVs) for cancer and adenomas were 4.5% and 40.3%, respectively. CONCLUSIONS: Screening had an adequate attendance rate and the majority of the indicators were satisfactory. The use of a one-day quantitative latex FOBT with no dietary restrictions, automation of the analytical procedure, and a positive threshold of 100 ng/ml has shown that a programme based on this test is feasible in both organizational and attendance terms. On the basis of this experience, the extension of the screening on a regional basis is suggested.

[Microbial growth and cold. Study of the particular case of Listeria monocytogenes]. / Croissance microbienne et froid. Etude du cas particulier de Listeria monocytogènes.

Some of micro-organisms are able to adapt themselves to hardest environmental conditions. So, about cold conditions, most of them can still grow at very low temperatures under 0 degree Celsius (nitrogen liquefied at -169 degrees C is the best way for preserving microbes). By another way some germs, qualified psychrotophic bacteria, grow quite easily between 0 degree C and +10 degrees C. Among these bacteria the author draw the attention to Listeria monocytogenes, a germ contaminating often foodstuffs and being responsible of deep diseases by eating food preserved in bad conditions (breaking off of refrigeration chain, bad use of domestic refrigerators). Recommendations are laid down to avoid these diseases, more particularly for frail consumers as immuno compromised adults.

corto genetically interacts with Pc-G and trx-G genes and maintains the anterior boundary of Ultrabithorax expression in Drosophila larvae.

In Drosophila melanogaster, segment identity is determined by specific expression of homeotic genes (Hox). The Hox expression pattern is first initiated by gap and pair-rule genes and then maintained by genes of the Polycomb-group (Pc-G) and the trithorax-group (trx-G). The corto gene is a putative regulator of the Hox genes since mutants exhibit homeotic transformations. We show here that, in addition to previously reported genetic interactions with the Pc-G genes Enhancer of zeste, Polycomb and polyhomeotic, mutations in corto enhance the extra-sex-comb phenotype of multi sex combs, Polycomb-like and Sex combs on midleg. corto also genetically interacts with a number of trx-G genes (ash1, kismet, kohtalo, moira, osa, Trithorax-like and Vha55). The interactions with genes of the trx-G lead to phenotypes displayed in the wing, in the postpronotum or in the thoracic mechanosensory bristles. In addition, we analyzed the regulation of the Hox gene Ultrabithorax (Ubx) in corto mutants. Our results provide evidence that corto maintains the anterior border of Ubx expression in third-instar larvae. We suggest that this regulation is accomplished through an interaction with the products of the Pc-G and trx-G genes.

Mutations in ccf, a novel Drosophila gene encoding a chromosomal factor, affect progression through mitosis and interact with Pc-G mutations.

We report herein the isolation of ccf, a new gene located in region 82E and essential for Drosophila development. This gene, expressed throughout development, encodes a novel product of 68 kDa which is found in the nucleus during interphase and labels, in a novel pattern, centrosomes and chromosome arms during mitosis. Mutations in ccf give rise to late larvae with small imaginal discs and to adults showing appendages of reduced size, consistent with CCF involvement in cell proliferation. Neuroblast squash analyses show that CCF is required for proper condensation of mitotic chromosomes and, therefore, for progression through mitosis. Furthermore, we observe that adult ccf mutants as well as animals overexpressing CCF during larval stages exhibit homeotic transformations. We also find that mutations in the Pc-G genes Polycomb, polyhomeotic and Enhancer of zeste are enhanced by ccf mutations. Finally, we show that the CCF protein binds to specific sites on polytene chromosomes, many of which are shared with the Posterior sex combs Pc-G protein. Together, these results suggest a role for the CCF protein in the maintenance of chromosome structure during mitosis and interphase.

Genetic and molecular analysis of terminal deletions of chromosome 3R of Drosophila melanogaster.

Terminal deletions of chromosome 3R are induced at a high frequency (3.2 x 10(-3)) by irradiating 45-4 Drosophila melanogaster females with a low dose of X-rays. The 45-4 line carries a white transgene inserted at 16 kb from the terminus and is homozygous for the mu-2 mutation, a gene involved in the repair of double-strand DNA breaks. Four of the 51 recovered deleted strains have lost modulo, the distalmost essential gene on chromosome 3R. Breakpoints of 22 deletions have been localised in a single hybridisation step, using pulsed-field gel electrophoresis to separate genomic DNA fragments obtained from digestion with a rare-cutter restriction enzyme. Breaks do not occur at random, but are rather clustered in three susceptible chromosomal domains. Backcross experiments resulting in transheterozygous (deleted chromosome/45-4) animals indicate that the activity of the white transgene is enhanced when the DNA break has occurred proximal to a critical position. This suggests that homologous chromosomal pairing distal to the critical position results in the definition of a more compact chromatin structure and, due to position effect, in the silencing of white.

Supragenic loop organization: mapping in Drosophila embryos, of scaffold-associated regions on a 800 kilobase DNA continuum cloned from the 14B-15B first chromosome region.

The supragenic loop organization of the Drosophila genome was investigated on a 800 kilobase (kb) DNA continuum from the 14B-15B first chromosome region. Nuclear scaffolds from 0-18 hr embryos were prepared with Laemmli's low-salt, detergent procedure and digested with restriction enzymes. Scaffold-associated regions (SARs) were mapped by probing Southern transfers of total, scaffold-associated and free DNA with a set of 70 recombinant phages overlapping the investigated genomic region. In all, 85 restriction fragments showed association to scaffolds. 12 of them were present in the majority of scaffolds. They bore strong SARs organizing the DNA molecule as consecutive loops with sizes ranging from 15 to 115 kb. 44 were present in only a fraction of scaffolds. They contained weak SARs subdividing the basic loops into smaller ones. 29 additional restriction fragments were present in a very small fraction of scaffolds. The position of SARs with respect to transcribed regions was investigated. Strong SARs appeared to be located on untranscribed DNA and to frame transcription units. In contrast, at least some weak SARs were shown to comap with transcribed regions or to reside within characterized transcription units. Statistical analyses established that strong and weak SARs were periodically positioned on the DNA continuum and that there was a potential contact point between scaffolds and the DNA continuum every 11 kb, or multiples thereof. Implications for SAR role(s) are discussed.

Extraction of major alkaloids from poppy straw with near-critical mixtures of carbon dioxide and polar modifiers.

Near-critical extraction of major alkaloids from poppy straw was performed successfully with a simple device consisting mainly of two chromatographic pumps and a pressure regulator. The optimum extractant, consisting of carbon dioxide, methanol and water, gave a quantitative extraction of thebaine, codeine and morphine in 20 min. The method was compared with a classical liquid-solid extraction procedure and carbon dioxide was shown to act as a transporting agent of the extraction solvent (methanol-water) into the vegetable matrix.

Direct separation of albendazole sulfoxide enantiomers by liquid chromatography on a chiral column deriving from (S)-N-(3,5-dinitrobenzoyl) tyrosine: application to enantiomeric assays on plasma samples.

The direct enantiomeric resolution of albendazole sulfoxide (SOABZ), an anthelmintic drug belonging to the benzimidazole class, is reported on a chiral stationary phase (CSP) synthesized by covalent binding of (S)-N-(3,5-dinitrobenzoyl)tyrosine-O-(2-propen-1-yl) methyl ester on a gamma-mercaptopropyl-silanized silica gel. A comparison with the resolution achieved on commercially available Pirkle-type CSPs obtained from N-(3,5-dinitrobenzoyl) derivatives of (R)-phenyglycine or (S)-phenylalanine is described. Some structurally related chiral sulfoxides including oxfendazole (SOFBZ) are also studied. Optimization of the mobile phase nature and composition is investigated showing that a hexane-dioxane-ethanol ternary mixture affords an almost baseline resolution (Rs = 1.25); however, in this case, albendazole sulfone (SO2ABZ) is eluted between the two sulfoxide enantiomers; accordingly, a hexane-ethanol mobile phase would be preferred for biological samples containing both metabolites. The influence of temperature on the resolution is depicted with a hexane-ethanol mobile phase. Finally, application to the enantiomeric assays of SOABZ in plasmatic extracts of rat, sheep, bovin, and man after oral administration of albendazole (sulfoxidized to SOABZ and SO2ABZ) is reported. Some distortions in the enantiomeric ratios are evidenced depending on the species.

Separation of opium alkaloids by carbon dioxide sub- and supercritical fluid chromatography with packed columns. Application to the quantitative analysis of poppy straw extracts.

The optimization of the separation of seven opium alkaloids by sub- and supercritical fluid chromatography (SFC) using packed columns and carbon dioxide as the primary mobile phase was studied. The influence of aminated polar modifiers on bare and aminopropyl-bonded silica was investigated. It was found that the presence of an amine in the mobile phase could enhance the retention of alkaloids on aminopropylsilica. Various separation schemes were possible depending on the type of analysis needed. An aminopropyl-bonded silica used with a carbon dioxide-methanol-triethylamine-water mixture (82.95:16.25:0.50:0.30, w/w) gave a very rapid separation (2 min). A bare silica with a carbon dioxide-methanol-methylamine-water mixture (83.37:16.25:0.15:0.23, w/w) gave longer analysis (10 min) but a higher resolution. This last procedure was applied to a poppy straw extract and to the determination of three alkaloids of interest after a peak purity study using a diode-array UV detector. For these alkaloids, SFC appears to be a promising technique for the routine analysis of opium alkaloids.

Automatic determination of urinary 4-hydroxy-3-methoxymandelic (vanillylmandelic) acid by liquid chromatography with electrochemical detection.

An automated liquid chromatographic method for the determination of urinary concentrations of 4-hydroxy-3-methoxymandelic acid (VMA) is described. Urine samples are purified by solid-phase extraction on an anion-exchange cartridge and automated on-line chromatographic elution is carried out using a Varian AASP (advanced automated sample processor) system. The column effluent is monitored with an electrochemical detector using a glassy carbon working electrode. The method allows the determination of VMA in 0.05 ml of normal urine with a relative standard deviation of less than 3%. The analysis time can be shortened by use of back-flushing technique, and the correlation with a classical (but non-automated) VMA analysis method is excellent.

Isolation and characterization of a region of the Drosophila genome which contains a cluster of differentially expressed maternal genes (yema gene region).

We have characterized a genomic clone of Drosophila melanogaster which codes for four transcripts that are synthesized during oogenesis, remain abundant in the preblastoderm embryo, and then vanish during gastrulation. One of the transcripts varies in concentration along the anterior-posterior axis of the oocyte. This cluster of maternally acting genes (yema) maps to 98 F3-10 on chromosome arm 3 R.

Retention of polycyclic aromatic hydrocarbons on an improved tetrachlorophthalimidopropyl silica.

An improved synthesis of a chemically bonded electron acceptor, namely tetrachlorophthalimidopropyl silica, is described. Factors governing the silane preparation and its bonding to silica have been studied, namely reaction temperature and duration, pretreatment of silica, specific area, pore diameter, washing of the bonded silica, influence of solvent drying. A ligand density of 2.7 mumol/m2 is obtained with reduced plate heights in the range 5-20 which demonstrate the absence of polymerization. The retention of six polycyclic aromatic hydrocarbons has been studied. The minimum capacity factors allow high recovery rates in non-polar media.

Resolution of enantiomeric amides on a Pirkle-type chiral stationary phase. A comparison of subcritical fluid and liquid chromatographic approaches.

Subcritical and supercritical fluid chromatography (SubFC and SFC) have been evaluated for the resolution of an homologous series of enantiomeric amides. The solutes were the 2-naphthoyl amides of an homologous series of amines, ranging from 2-aminobutane to 2-aminoctane, and the p-methyl-, p-methoxy- and p-chlorophenylamides of 2-aminoheptane. The chiral stationary phase (CSP) used was the covalent form of (R)-N-(3,5-dinitrobenzoyl)phenylglycine. In liquid chromatography (LC) the mobile phase comprised hexane-2-propanol--acetonitrile (97:3:0.5) at a flow-rate of 2 ml/min and temperatures of 20-35 degrees C. In SFC, the mobile were various mixtures of carbon dioxide and polar modifiers, such as alcohols, chloroform and water. For the best conditions in LC, the chiral resolution, alpha, increased through the homologous series from alpha = 1.03 for the amide derived from 2-aminobutane to alpha = 1.11 for the 2-aminooctane amide. The values of alpha observed for the pi-basic amides of 2-aminoheptane (p-methyl and p-methoxy) were greater than that observed for the pi-acidic amide (p-chloro), i.e., alpha = 1.08 versus 1.04. The selectivities, resolutions and efficiencies obtained by LC and SubFC were similar. These results indicate that the mechanism of chiral recognition is the same in LC and SubFC and that the methods should be interchangeable. The actual analysis time for SubFC was significantly shorter than that required for LC: as short as 2 min for the 2-aminooctane amide, whereas LC takes over 10 min under the best conditions.

Overproduction of the first three enzymes of pyrimidine nucleotide biosynthesis in Drosophila cells resistant to N-phosphonacetyl-L-aspartate.

Drosophila cells were treated in vitro with N-phosphonacetyl-L-aspartate (PALA) which is a specific inhibitor of aspartate transcarbamylase, the second enzyme of the pyrimidine biosynthetic pathway. By stepwise selection using increasing amounts of this inhibitor, PALA-resistant (PALAr) stable clones have been isolated. Enzymatic activities of aspartate transcarbamylase, carbamyl phosphate synthetase and dihydro-orotase, borne by the same multifunctional protein, CAD, are increased 6-12-fold in these resistant clones compared with parental cells. The aspartate transcarbamylase in PALAr cells is shown by physical, kinetic and immunological criteria to be normal. The data from immunotitration and immunoblotting experiments indicate that the increased enzyme activities result from the overproduction of CAD.

Studies on chromatin organization in a nucleolus without fibrillar centres. Presence of a sub-nucleolar structure in KCo cells of Drosophila.

In embryonic cell-line derivative KCo of Drosophila melanogaster, the nucleolus, like most nucleoli, contains a small proportion of ribosomal DNA (1-2% of the total nucleolar DNA). The ribosomal DNA is virtually the only active gene set in the nucleolus and is found among long stretches of inactive supercoiled heterochromatic segments. We have demonstrated by use of a Feulgen-like ammine-osmium staining procedure that, depending on the state of growth, more or less fibres of decondensed DNA emanating from the intra-nucleolar chromatin (which is in continuity with the nucleolus-associated chromatin) ramify and unravel within the central nucleolar core to be transcribed. The nucleolus expands or contracts with the variation of activity and could belong to a supramolecular matricial structure such as is shown after extraction of the nuclei. After a long period of exposure to high doses of actinomycin D, the central nucleolar core became an homogeneous fibrous structure that could be interpreted as an aggregate of protein skeletal elements. The mechanism of repression and derepression of the nucleolar chromatin could thus be explained by a mechanism involving in part a sub-nucleolar structure. We propose a schematic organization of the nucleolar chromatin in KCo cells of Drosophila and discuss it in relation with other nucleolar organizations.

Nucleolar organizer structure and activity in a nucleolus without fibrillar centres: the nucleolus in an established Drosophila cell line.

Classical electron-microscopic techniques (enzymic digestion, EDTA regressive staining) allied with autoradiographic studies after [3H]uridine incorporation or after RNA synthesis initiated by an exogeneous RNA polymerase in the presence of tritiated GTP, enabled us to describe the fine structure and activity of the nucleolus in an established Drosophila cell line. This nucleolus is composed of a large central multilobed core containing proteins, RNA molecules and a DNA-containing component. This core is surrounded by and connected to large clumps of dense fibrillar nucleolus-associated chromatin, which are intermingled with fibrillogranular ramifications extending from the core towards the nuclear envelope. These ramifications are covered by granules of ribosomal ribonucleoprotein. As shown by EDTA regressive staining the nucleolar core contains a ribonucleoprotein network, which unravels and ramifies within a fibrous matrix. RNA synthesis takes place at the level of this network in the internal part of the core. The molecules synthesized are associated with proteins and are exported out of the core in the form of granules. Although it is composed of the same constituents as other nucleoli, the nucleolus of Drosophila cells seems to be less organized, in that it never displays fibrillar centres, which have been referred to as the nucleolar counterparts of the nucleolus-organizers in a wide variety of organisms.