Chemoprevention of colorectal cancer: role of antioxidant vitamins.
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Antioxidants↗
Biomedical subjects
R Santucci
Publications and source records attributed to R Santucci.
Failure of intrauterine insemination in male immunological infertility in cases in which all spermatozoa are antibody-coated.
OBJECTIVE: To determine if the overcoming of the cervical mucus barrier removes the interference of sperm-bound antibodies with fertility. DESIGN: Prospective case series. SETTINGS: University-based intrauterine insemination (IUI) homologous program. PATIENTS: Nineteen patients with all spermatozoa in the ejaculate coated by antisperm antibodies. As control group, 86 consecutive patients without antisperm antibodies, treated for oligoasthenozoospermia or mucus hostility. INTERVENTIONS: Intrauterine inseminations (at least 3 attempts per couple). MAIN OUTCOME MEASURES: The outcome of IUIs, demographic, and seminal parameters were compared between the two groups. RESULTS: No pregnancy occurred in the couples with male immunological infertility, treated by 110 IUIs. Twenty-three pregnancies occurred in 22 (25.6%) of the control group couples who were treated by 411 IUIs. In the group of patients without antisperm antibodies, we demonstrated that the pregnancy rate (PR)/couple in oligoasthenozoospermia without teratozoospermia was similar to that achieved in normozoospermia (35% versus 38.9%), whereas it was significantly affected by teratozoospermia (3.6%). Only three patients with antisperm antibodies had teratozoospermia. Comparing the PR per couple and per cycle between the two groups of patients (with and without antisperm antibodies), excluding the patients with teratozoospermia, significant differences resulted (P less than 0.005 and P less than 0.005, respectively). The motile sperm count was not significantly different between the two groups, which also resulted to be homogeneous for demographic data. Moreover, the motile sperm count was not different between the patients with and without antisperm antibodies, who had successful IUI. CONCLUSIONS: The analysis of this trial suggests that the failure of IUI in the treatment of male immunological infertility is imputable to antisperm antibodies when they involve all spermatozoa, regardless of semen quality.
Autoantibodies↗
Rectal cell proliferation and colorectal cancer risk level in patients with nonfamilial adenomatous polyps of the large bowel.
The authors evaluated cell kinetics of apparently normal rectal mucosa in the following subjects: 25 with single small adenoma (smaller than 10 mm) of the large bowel, 12 with multiple small adenomas, 28 with a single large adenoma (larger than 10 mm), 22 bearing multiple adenomas among which at least one was larger than 10 mm, 32 with cancer of the large intestine, and 32 controls without colorectal diseases. The study was performed by means of incubation of biopsy specimens with tritiated thymidine and autoradiography. The labeling index was similar in all of the groups. However, patients with one or more large adenomas showed a shift of the proliferative compartment toward the top of the crypts similar to that observed in patients with cancer. This abnormal proliferative pattern was not noticed in patients with one or more small adenomas and was not related to the number of adenomas of each subject. The presence of defects of cell growth in the normal rectal mucosa of patients with large adenomas may indicate that subjects with this abnormality are at high risk of adenoma growth and progression to cancer.
Adult↗
Influence of allosteric effectors on the heme conformation of dromedary ferrous nitrosylhemoglobin detected by XANES spectroscopy.
The changes of the Fe heme-active site conformation of dromedary (Camelus dromedarius) nitrosylhemoglobin (HbNO) induced by inositol hexakisphosphate (IHP) and chlofibric acid (CFA) have been studied by using X-ray absorption near-edge structure (XANES) spectroscopy. Structural information has been determined by multiple scattering analysis of the Fe K-edge XANES spectra. The proximal histidine is found to move away from iron centers by about 0.4 Angstrom on the average over the four hemes upon binding of CFA or stoichiometric amount of IHP. In molar excess of polyanion or in the simultaneous presence of IHP, CFA and chloride, the proximal histidine moves back to a position very close to that observed in pure buffer; yet, the structure modulation induced by the allosteric effectors is not completely reversible. Such findings parallel with the functional properties and the spectroscopic (e.g., EPR and absorbance) characteristics of HbNO.
Animals↗
Use of 'solid-state' promoters in the electrochemistry of cytochrome c at a gold electrode.
The direct electrochemistry of cytochrome c at a gold electrode was investigated by cyclic voltammetry using, as promoters, microperoxidase (the haem-undecapeptide obtained by hydrolysis of cytochrome c), Fe(III)-protoporphyrin IX or protoporphyrin-IX, all entrapped in a cellulose triacetate membrane. The results indicate that these immobilized systems strongly enhance the rate of electron transfer between the protein in solution and the electrode surface, and thus behave as 'solid-state' promoters, though with differing efficiencies. These results are of interest because they raise the possibility of engineering an efficient and versatile promoter active also at inert electrode surfaces.
Animals↗
Correlation between bromodeoxyuridine labelling and ornithine decarboxylase levels in normal rectal mucosa of patients with colorectal adenoma.
We studied rectal cell proliferation by means of bromodeoxyuridine labelling and ornithine decarboxylase activity assay in 16 patients with colorectal adenoma. In each patient, three rectal biopsy specimens taken from normal-appearing mucosa were incubated with bromodeoxyuridine (BrdU), fixed in ethanol and stained with avidin-biotin peroxidase complex using a monoclonal antibody against BrdU. In addition, two biopsies were homogenized and incubated with [1-14C]-ornithine for ornithine decarboxylase (ODC) assay. A direct, significant correlation was found between BrdU-labelling index and ODC levels in the mucosa (r = 0.6511, P less than 0.01). We conclude that BrdU labelling and ODC activity assay give comparable results in the analysis of cell proliferation rate of rectal mucosa. These methods are useful to investigate rectal cell proliferation pattern of patients with increased risk of colorectal cancer.
Adenoma↗
Effect of sperm-antibodies on acrosome reaction of human sperm used for the hamster egg penetration assay.
The effect of anti-sperm antibodies (ASA) on the rate of acrosome reactions (AR) during "in vitro" capacitation of human sperm used for the hamster egg penetration assay (HEPA) was assessed. Motile sperm suspensions from donors were exposed to several sera and seminal plasma with sperm head-directed ASA, then they were washed and capacitated "in vitro." After capacitation, the proportion of acrosome-reacted viable sperm was assessed by staining with Fluoresceinated Pisum Sativum Agglutinin and supravital stain Hoechst 33258. ASA of any immunoglobulin class did not significantly affect either the AR rate, or the hamster egg penetration rate. In conclusion, interference of ASA on spontaneous AR rate during "in vitro" capacitation can not be advocated as an explanation of the impairment of the interaction of human sperm with egg or its vestments, which have been reported in several studies.
Acrosome↗
Cell proliferation kinetics as a marker of gastric cancer risk.
Although cell proliferation studies on gastric mucosa are relatively few compared to the results obtained in the large bowel, they brought important contributions to our knowledge of the mechanisms involved in the development and progression of neoplasia. In normal gastric mucosa, the proliferative zone is limited to the neck region of the glands. In diseases at risk for gastric cancer, such as chronic atrophic gastritis, two main features have been observed: an increased cell proliferation rate and expansion or upward displacement of the proliferative compartment. However, while a high cell turnover rate can be due to many stimuli such as inflammation or the effect of hormones (i. e. gastrin), the expansion of the proliferative compartment is more evident with the development and progression of neoplasia. It could be due to an error in the control of cell proliferation and maturation. This kinetic pattern is probably a marker of gastric cancer risk. Application of these observations in clinical investigations are the search for proliferative abnormalities and other phenotypical markers in order to define an individual profile of cancer risk, and to evaluate the effects of xenobiotics or dietary intervention in controlled trials.
Biomarkers, Tumor↗
Horse heart myoglobin reconstituted with a symmetrical heme. A circular dichroism study.
Proton NMR studies on myoglobins and hemoglobins reconstituted with non-natural hemes, possessing different side chains in the pyrrolic rings, have provided interesting information for the understanding of the mechanism governing heme reorientation in the globin pocket, during synthesis of the native protein in vivo or in the reconstitution process in vitro. More recently, circular dichroism (CD) studies have been reported as a qualitative, alternative tool, with respect to 1H-NMR for detecting heme disorder in a reconstituted myoglobin or hemoglobin. In this paper, a CD study is reported on the reconstitution of horse heart myoglobin with protoheme XIII, a heme possessing true rotational symmetry about its alpha, gamma-meso axis. The results obtained show that the reconstitution product with this heme, which binds to the apoprotein with high affinity, not dissimilar from that of the natural heme, is characterized by a CD spectrum with bands possessing rotational strengths much lower than in the native protein. Furthermore, the CD changes detected as a function of time, during heme reorientation, in the case of natural heme, are absent when the apoprotein is reconstituted with protoheme XIII. These data provide independent evidence for reorientation of the natural heme, which follows its insertion into the protein matrix.
Animals↗
A spectroelectrochemical study of microperoxidase at bare and gold-plated RVC thin-layer electrodes.
Direct electrochemistry of microperoxidase (the heme-undecapeptide from cytochrome c) has been followed at a bare and a gold plated RVC thin-layer electrode, using the spectropotentiostatic method or voltabsorptometry. Both techniques yield 'clean' and undistorted signals; their analysis easily provides quantitative information for the electrochemical parameters of microperoxidase and shows that spectroelectrochemistry is a powerful method to study the redox behavior of metalloproteins or their active site fragments.
Carbon↗
Voltammetric studies on the electrochemical behaviour of membrane-entrapped hemes.
The electrochemical behaviour of Fe(III)-protoporphyrin IX entrapped into a cellulose triacetate membrane has been investigated by cyclic voltammetry. The physical entrapment into a solid matrix does not modify the redox properties of the entrapped hemes, which also act as efficient promoters in the electrochemistry of cytochrome c. Such a system represents a promising example of a simple 'solid-state' promoter, and stimulates further investigations in order to obtain more complex systems that may be of significance for basic and applied bioelectrochemistry.
Electrochemistry↗
Effect of sex and age on rectal cell renewal in humans.
We evaluated the influence of age and sex on rectal cell proliferation of 69 hospital controls and 66 patients with colorectal adenomas, by means of incubation of rectal biopsies with tritiated thymidine and autoradiography. In particular, we evaluated the labeling frequency in the upper 40% of rectal crypts (0 h), actually considered as a reliable kinetic marker of colon cancer risk. A direct correlation between 0h and age was found in control subjects (P less than 0.02) but not in adenomas patients (P = NS). Moreover, control subjects over 65 years of age showed a shift of the proliferative compartment similar to that observed in the adenomas group. After adjusting for the age, we did not observe any significant effect of the sex of patients or controls on their cell kinetics parameters. Our results are in agreement with those previously reported on smaller series and with epidemiological studies which indicate a high risk for developing colorectal neoplasia in the elderly subjects.
Adenoma↗
Effect of sperm morphology and motile sperm count on outcome of intrauterine insemination in oligozoospermia and/or asthenozoospermia.
Eighty-six couples with long-standing infertility and poor postcoital test, due to oligozoospermia and/or asthenozoospermia (68 cases) or mucus hostility (18 cases), were treated by 411 intrauterine inseminations (IUI) with motile sperm suspensions from the husband's semen. The pregnancy rate per couple in the group with abnormal semen was lower than in the group with mucus hostility (22% versus 38.9%). Influence of seminal and other parameters on outcome of IUI was assessed by discriminant analysis, and a significant correlation with pregnancy rate was found for motile sperm count and sperm morphology. Teratozoospermia (normal morphology less than 50%) affected the outcome of IUI both when associated with moderate oligozoospermia and/or asthenozoospermia (motile sperm count greater than or equal to 5 X 10(6)/mL) (success rate per couple: 11.1%), and, even more, when associated with severe oligozoospermia and/or asthenozoospermia (motile sperm count less than 5 X 10(6)/mL), where no pregnancy was achieved. In the absence of teratozoospermia, the success rate per couple both in severe and in moderate oligozoospermia and/or asthenozoospermia had similar results (33.3% versus 35.7%). In conclusion, the absence of teratozoospermia appears to be an effective criterion for selecting couples with infertility due to oligozoospermia and/or asthenozoospermia who may benefit from IUI.
Adult↗
Prostaglandin E2 and F2 alpha levels in the duodenal and antral mucosa of non-ulcer dyspeptic and duodenal ulcer patients.
In the present study we evaluated the contents of endogenous prostaglandins type E2 and F2 alpha in the antral mucosa, and the type E2 in the duodenal mucosa in a group of thirty non-ulcer dyspeptics in comparison with a group of thirty duodenal ulcer patients. A significantly reduced concentration of duodenal and antral PGE2 was found in ulcer patients as compared with dyspeptic subjects. A significantly increased concentration of antral PGE2 was observed in cases with active superficial antral gastritis, either in dyspeptics or in duodenal ulcer patients, as compared with normal antrum cases. A significantly increased level of PGF2 alpha was found in active superficial gastritis of the dyspeptic group.
Adult↗
Membrane-entrapped microperoxidase as a 'solid-state' promoter in the electrochemistry of soluble metalloproteins.
Immobilization of biological systems in solid matrices is presently of great interest, in view of the many potential advantages associated with both the higher stability of the immobilized macromolecules and the potential utilization for biotechnology. In the present paper the electrochemical behaviour of the undecapeptide from cytochrome c (called microperoxidase) tightly entrapped in cellulose triacetate membrane is reported; its utilization as 'solid-state' promoter in the electrochemistry of soluble metalloproteins is presented. The results obtained indicate that: (i) membrane-entrapped microperoxidase undergoes rapid reversible electron transfer at a glassy carbon electrode; (ii) the electrochemical process is diffusion-controlled; (iii) entrapped microperoxidase acts as 'solid-state' promoter in the electrochemistry of soluble cytochrome c and of azurin.
Azurin↗
Influence of globin structure on the heme in dromedary carbonmonoxyhemoglobin.
By use of X-ray absorption near-edge structure (XANES), circular dichroism, and visible absorption spectroscopies, dromedary carbonmonoxyhemoglobin has been characterized structurally and functionally. By consideration of the experimental results the following view emerges: (i) the quaternary structure is not the unique factor determining the tertiary environment around the heme, and (ii) the multiplicity of interactions between hemoglobin and solvent components induces a large number of globin conformations, which somehow affect the conformation of the heme such that the structural parameters (i.e., the doming of porphyrins, the movements of the iron relative to the heme plane, the distortion of the ligand field, and the change in the Fe-C-O angle) can be uncoupled.
Animals↗
Topical administration of 5-aminosalicylic acid: a therapeutic proposal for the treatment of pouchitis.
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Administration, Topical↗
Structural transitions of carboxymethylated cytochrome c: calorimetric and circular dichroic studies.
Circular dichroism and differential scanning calorimetry studies on the unfolding-refolding process of native and carboxymethylated cytochrome c, induced either by temperature or chemical agents, have been performed. The results have shown that the modified protein has a decreased conformational stability with respect to the native state, in agreement with a structure less compact, but still highly folded, which behaves as a thermodynamically stable "intermediate" between native and fully unfolded cytochrome c.
Calorimetry, Differential Scanning↗