Prevalence of molar incisor hypomineralization among school children in Rome, Italy.

Molar incisor hypomineralization (MIH) is a highly prevalent condition associated with increased caries experience, dental pain and treatment need. Aim of this study was to determine the prevalence and severity of MIH in a group of 7-8 years old primary school children living in Rome, Italy; and to assess the association with caries experience and possible perinatal risk factors. A survey has been conducted in the city of Rome, between April 2019 and March 2020 with a total of 49 primary schools and 176 2nd grade primary school classes and a total of 3611 children being involved. Of these, a subset of 346 children of 21 primary schools was selected for the epidemiological investigation. The prevalence of MIH was of 18.2%, with girls showing twice the probability of being subject to a mild-severe condition. Molar location was present in 71.4%, while location on both molar plus incisor was present in 28.6% of cases. The mean DMFT was 0.44 ± 0.78, "D" was 0.17 ± 0.58; the mean dmft was 1.7 ± 2.56, "d" was 1.32 ± 2.21. Female gender, caries experience, insufficient oral hygiene were risk factors. The incidence of MIH is increasing in the pediatric population. Knowledge about diagnosis and treatment options should be disseminated among dental professionals.

Apc gene mutation is associated with a dominant-negative effect upon intestinal cell migration.

Apc-associated intestinal tumor formation appears to require functional loss of both Apc alleles. Apc has, therefore, been classified as a tumor suppressor gene. Loss of APC protein function results in increased intracellular beta-catenin, a molecule important to both cell-cell adhesion and regulation of cellular growth. In mice bearing a germ-line Apc mutation, we found that enterocyte beta-catenin expression was also increased in histologically normal intestinal mucosa. Enterocyte crypt-villus migration was decreased by 25%, and treatment of Min/+ animals with sulindac sulfide normalized both beta-catenin expression and enterocyte migration. Our data suggest that alterations in enterocyte migration occur in cells bearing a single mutant Apc allele, and that sulindac sulfide may normalize enterocyte growth in these cells.

Cyclooxygenase-2 overexpression and tumor formation are blocked by sulindac in a murine model of familial adenomatous polyposis.

Inducible cyclooxygenase (Cox-2), also known as prostaglandin H synthase 2 (PGH-2) is a key enzyme in the formation of prostaglandins and thromboxanes. Cox-2 is the product of an immediate-early gene that is expressed in response to growth factors, tumor promoters, or cytokines. Overexpression of Cox-2 is associated with both human colon cancers and suppression of apoptosis in cultured epithelia] cells, an activity that is reversed by the nonsteroidal anti-inflammatory drug, sulindac sulfide. To address the relationship between Cox-2, apoptosis, and tumor development in vivo, we studied C57BL/6J-Min/+(Min) mice, a strain containing a fully penetrant dominant mutation in the Apc gene, leading to the development of gastrointestinal adenomas by 110 days of age. Min mice were fed AIN-76A chow diet and given sulindac (0.5 +/- 0.1 mg/day) in drinking water. Control Min mice and homozygous C57BL/6J-+/+ normal littermates lacking the Apc mutation (+/+) were fed AIN-76A diet and given tap water to drink. At 110 days of age, all mice were sacrificed, and their intestinal tracts were examined. Control Min mice had 11.9 +/- 7.8 tumors per mouse compared to 0.1 +/- 0.1 tumors for sulindac-treated Min mice. As expected, +/+ littermates had no macroscopic tumors. Examination of histologically normal-appearing small bowel from Min animals revealed increased amounts of Cox-2 and prostaglandin E(2) compared to +/+ littermates. Using two different in situ techniques, terminal transferase-mediated dUTP nick end labeling and a direct immunoperoxidase method, Min animals also demonstrated a 27-47% decrease in enterocyte apoptosis compared to +/+ animals. Treatment with sulindac not only inhibited tumor formation but decreased small bowel Cox-2 and prostaglandin E(2) to baseline and restored normal levels of apoptosis. These data suggest that overexpression of Cox-2 is associated with tumorigenesis in the gastrointestinal epithelium, and that both are inhibited by sulindac administration.

P450 enzymes of estrogen metabolism.

Endogenous and exogenous estrogens undergo extensive oxidative metabolism by specific cytochrome P450 enzymes. Certain drugs and xenobiotics have been found to be potent inducers of estrogen hydroxylating enzymes with C-2 hydroxylase induction being greater than that of C-16 hydroxylase. Oxygenated estrogen metabolites have different biological activities, with C-2 metabolites having limited or no activity and C-4 and C-16 metabolites having similar potency to estradiol. Pathophysiological roles for some of the oxygenated estrogen metabolites have been proposed, e.g. 16 alpha-hydroxyestrone and 4-hydroxyestrone. These reactive estrogens are capable of damaging cellular proteins and DNA and may be carcinogenic in specific cells.

The nonpsychoactive component of marijuana cannabidiol modulates chemotaxis and IL-10 and IL-12 production of murine macrophages both in vivo and in vitro.

Cannabidiol is the main nonpsychoactive component of marijuana. We examined the ability of in vivo and in vitro cannabidiol to interfere with the production of interleukin (IL)-12 and IL-10 by murine macrophages and to modulate macrophage chemotaxis. Cannabidiol added in vitro to peritoneal macrophages significantly increased IL-12 and decreased IL-10 production. The CB1 and CB2 receptor antagonists prevented this modulation. Macrophages from animals treated with cannabidiol at the dose of 30 mg kg(-1) either orally or i.p. produced higher levels of IL-12 and lower levels of IL-10 in comparison to controls, and the CB receptor antagonists did not prevent these effects. Cannabidiol dose-dependently decreased fMLP-induced chemotaxis of macrophages, and the CB2 receptor antagonist prevented this decrease.

Direction of estradiol metabolism as a control of its hormonal action--uterotrophic activity of estradiol metabolites.

The uterotrophic activities of the catechol metabolites of estradiol 2-hydroxyestrone, 2-methoxyestrone and 2-hydroxyestradiol were measured under conditions of continuous administration of sc implanted paraffin pellets. The activity of these estrogens was compared to that of estradiol-17beta and its other principal metabolites estrone, estriol and 15alpha-hydroxyestriol (estetrol). The major catechol estrogens, 2-hydroxyestrone and 2-methoxyestrone, and the pregnancy metabolite, 15alpha-hydroxyestriol, exhibited no uterotrophic activity. The minor catecholestrogen, 2-hydroxyestradiol, showed some activity whose character was different from that exhibited by implants of estradiol, estrone and estriol all of which were equipotent uterotrophic agents. Implants of 2-hydroxyestrone in the presence of estradiol or estriol pellets did not diminish the response to the latter indicating that the 2-hydroxyestrone is not antiestrogenic under these conditions. It is concluded that the direction of estradiol metabolism can have a profound influence on the expression of peripheral hormonal activity with hydroxylation at C-2 terminating and hydroxylation at C-16 extending it.

Impact of continuously administered catechol estrogens on uterine growth and luteinizing hormone secretion.

The biological activity of a series of natural catechol estrogens was examined under conditions of continuous administration. 2-Hydroxyestradiol (2OH-E2), 2-methoxyestradiol (2MeOE2), 4-hydroxyestrone (4OH-E1), 4-methoxyestradiol (4MeOE2), 2-hydroxyestrone (2OH-E1), and 4-methoxyestrone (4MeOE1) were delivered at the rate of 1 microgram/h from osmotic pumps implanted in ovariectomized rats. Uterine growth and plasma LH concentrations were measured 24, 48, and 72 h after implantation. Little or no uterotropic activity was exhibited by the 2-hydroxylated metabolites 2OH-E1 and 2MeOE2 at any interval, while 2OH-E2 exhibited anomalous uterotropic activity, which terminated at 48 h. The 4-hydroxylated compounds 4MeOE2, 4OH-E1, and 4MeOE1 all produced substantial and progressive uterine growth. Tonic LH secretion was suppressed by 2OH-E2, 4OH-E1, and 4MeOE1 in proportion to their uterotropic activity. 2OH-E1 was the only substance which increased plasma LH concentrations. The nuclear receptor occupancy by 2OH-E2 was substantially shorter than that of E2. Binding studies of the test and other related estrogens to the uterine cytosol estradiol receptor showed that their relative binding affinities in many instances did not correlate with their biological activities.

Biological properties of 16 alpha-hydroxyestrone: implications in estrogen physiology and pathophysiology.

Metabolism of estradiol in men with cirrhosis and subjects with systemic lupus erythematosus results in an excessive formation of 16 alpha-hydroxyestrone. Examination of the biological activity of this metabolite showed that it is a potent uterotropic agent and that it exhibits minimal affinity for the human sex hormone-binding globulin. These biological characteristics are consistent with a hyperestrongenic response to the substance, which may be reflected in the pathology and etiology of these diseases.

Absence of measurable 2-hydroxyestrone in the rat brain: evidence for rapid turnover.

The free 2-hydroxyestrone content of female rat brains was measured by two independent methods, including a direct radioimmunoassay and enzymatic conversion to stable O-methylated derivatives followed by a specific radioimmunoassay for the latter. The sensitivities of the two procedures were 10 pg and 5 pg respectively and the recoveries were greater than 85%. Neither assay method was able to detect any measurable endogenous 2-hydroxyestrone in the female rat brain at any stage of the ovulatory cycle. It is suggested that a high turnover rate of 2-hydroxyestrogens in the rat brain precludes the accumulation of detectable quantities of these metabolites in central tissues.

Measurement of the estradiol receptor in human breast tissue by the immobilized antibody method.

A simple immobilized antibody procedure for estradiol receptor detection has been applied to samples of human breast tissue cytosols previously assayed by the charcoal-dextran method. Good agreement between the two procedures was realized confirming the validity of the immobilized antibody assay.

Distinct forms of hepatic androgen 6 beta-hydroxylase induced in the rat by indole-3-carbinol and pregnenolone carbonitrile.

The ability of indole-3-carbinol (IC), an anticarcinogen present in cruciferous vegetables, to induce CYP1A1, CYP1A2, CYP2B1/2, CYP2E1 and CYP3A1/2 in female rat liver was determined by Western analysis using monoclonal antibodies and compared to effects produced by pregnenolone carbonitrile in animals of both sexes. The ontogeny of induction of these cytochrome P450 isozymes in response to oral administration of IC was also investigated. An inverse correlation was observed between the 6 beta-hydroxylation of androsterone (A) and the induction by IC of CYP3A1/2, the P450 isozyme responsible for the bulk of hepatic 6 beta-hydroxylation of 4-androstenedione (AD). The effect of inhibitors on the formation of 6 beta-OHA from A or AD was also determined and shown to differ from their action on the P450 isozymes involved in the formation of the 6 beta-hydroxylated derivatives of AD or lithocholic acid. The results indicate that the enzyme induced by IC is distinct from the CYP3A1/2 which catalyzes hydroxylations at position 6 beta, allylic in AD but not in the fully saturated ring system of A. The increased hepatic conversion of A to its biologically less active 6 beta-OHA metabolite after treatment of female rats with IC could possibly contribute to the anticarcinogenic action of indole carbinols. It is also proposed that the action of multiple inducers present in cruciferous and other vegetables might produce androgen metabolic profiles very different from those produced by individual components isolated from them.

16 alpha-hydroxylation of estradiol: a possible risk marker for breast cancer.

From these results we may conclude that estradiol 16 alpha-hydroxylation is highly correlated with tumor incidence, and that the reaction is partly regulated by MMTV and the rest by genetic influences. Elevated hydroxylation appears to be an autosomal dominant trait that is highly specific for estradiol. It is also pertinent that the product of the 16 alpha-hydroxyestrone reaction is a potent estrogen that is capable of binding covalently to amino acids and nucleotides, including the estrogen receptor molecule. The results obtained in these studies establish the usefulness of the mouse model for studying the interrelationship between enhanced 16-hydroxylation of estradiol and the incidence of mammary tumors.

Aspirin prevents tumors in a murine model of familial adenomatous polyposis.

BACKGROUND: Both human and murine studies suggest that anti-inflammatory drugs prevent intestinal neoplasia. The purpose of this study was to investigate the role of aspirin as a chemopreventive agent for colorectal cancer. METHODS: We administered aspirin to the Min/+ mouse, an animal with a germline mutation in Apc, a gene that is essential for normal epithelial cell growth and differentiation. Apc mutation increases cytoplasmic beta-catenin, a regulatory protein associated with the cytoskeleton. Min/+ mice develop multiple intestinal adenomas and exhibit altered cell growth in the preneoplastic intestinal epithelium. RESULTS: Aspirin decreased the rate of tumor formation in Min/+ mice by 44%. Aspirin also normalized enterocyte growth by increasing apoptosis and proliferation in the preneoplastic intestinal mucosa. Finally, aspirin produced a decrease in intracellular beta-catenin levels, suggesting that modulation of this protein is associated with tumor prevention. CONCLUSIONS: These data confirm a role for aspirin in suppression of Apc-associated intestinal carcinogenesis.

Uterine estrogen receptor binding of catecholestrogens and of estetrol (1,3,5(10)-estratriene-3,15alpha,16alpha,17beta-tetrol).

The binding affinities for the catecholestrogen metabolites of estradiol and of their methyl ethers for the rat uterine cytosol estrogen receptors were examined. Similarly the binding of the fetal estradiol metabolite, 15alpha-hydroxyestriol (estertrol) was also measured. All of the catecholestrogens showed binding affinities far in excess of their uterotrophic potency. This is different from estriol, the product of the alternative metabolic pathways and suggests that the direction of estradiol metabolism may have an important role in the modulation of estrogenic activity of the female sex hormone.

Relationships of sex hormone levels to dependence in activities of daily living in the frail elderly.

OBJECTIVES: We undertook this nursing home study in order to determine the relationships between dependency in activities of daily living (ADL) and blood levels of estrone, testosterone, androstenedione, and dehydroepiandrosterone (DHEA). Little is known about this issue. METHODS: cross-sectional study of 370 nursing home residents. Hormone levels in blood specimens drawn in 1997 and 1998 were correlated with degree of ADL dependency recorded in medical charts. RESULTS: Because of multiple comparisons associations were deemed significant for P-values < or =0.017 for males and < or =0.0125 for females. In males, the following were inversely related: testosterone levels with dependency in transferring and eating; estrone with eating and a summary ADL index; and androstenedione with toileting and a summary ADL index (in all cases, r=-0.4; P=0.007-0.015). Inverse trends existed between testosterone levels and dependency in mobility and a summary ADL index; and androstenedione and eating (in all cases r=-0.3; P=0.030-0.055). Among females the following were directly related: estrone levels with dependence in mobility, toileting, transferring, and a summary ADL index; and DHEA with transferring and a summary ADL index (r=0.2-0.3, P=0.0001-0.01). Trends existed between estrone and eating, and DHEA and toileting (r=0.1-0.2, P=0.04). CONCLUSION: In male residents, higher sex hormone levels are associated with better ADL performance. Among females the opposite is true. While further studies are needed to elucidate these relationships, our results and recent findings of others suggest sex hormone actions in older women differ from those in younger populations. A possible stress-related mechanism is also presented.

The effects of polyoxyethylated cholesterol on fecal bile acids and nitrogen and on cholesterol balance in rats.

Polyoxyethylated cholesterol (POEC) is a water soluble derivative of cholesterol which decreases cholesterol absorption in rats without affecting body weight, fatty acid excretion, or intestinal histology. In the present study rat feces were analyzed for cholic, deoxycholic, chenodeoxycholic, muricholic and lithocholic acid following 3 months of feeding a standard or a 2% enriched cholesterol diet with or without 1.5% POEC. In rats maintained on the cholesterol free diet, POEC increased total bile acids (mg/day) by 50% from 14 +/- 3 to 21 +/- 3 (mean +/- SEM) but only the increase in chenodeoxycholic acid was significant (P less than 0.05). The corresponding POEC effect in the 2% cholesterol diet was 31% (70 +/- 8 to 93 +/- 3, P less than 0.01). Fecal nitrogen and serum cholesterol did not vary among groups. Comparing these data with neutral steroid excretion previously determined showed that POEC in the cholesterol-free diet increased the negative cholesterol balance more than three-fold (34 +/- 7 vs 118 +/- 13 P less than 0.01). In rats fed 2% cholesterol, POEC caused a negative cholesterol balance of 222 +/- 8 compared to the control of 27 +/- 52 (P less than 0.01). The data indicate that POEC exerts complex effects in the intestinal tract which increase both bile acid and cholesterol excretion.

The role of 2-methoxyestrone in estrogen action.

The plasma and tissue concentrations of 2-methoxyestrone (2-MeOE1) and 2-hydroxyestrone (2-OHE1) were measured in immature rats. The plasma levels of 2-MeOE1 were found to be high at birth and to decrease through puberty, when the low levels found in the adult rats were achieved. 2-OHE1 was undetectable in the plasma and brain, and barely detectable in the uterus and liver. 2-MeOE1 was undetectable in the brain and uterus, but high in the liver. The affinity of 2-MeOE1 and 2-OHE1 for rat alpha-fetoprotein was found to be low, while the affinity of estradiol, estrone, 4-hydroxyestrone, and 4-fluoroestradiol was high. This data suggests that 2-OHE1 and 2-MeOE1 would be available to estrogen target tissues in the fetal and neonatal rat. Although these metabolites lack uterotropic activity they are capable of acting in the liver. It is suggested that the plasma 2-MeOE1 of neonatal rats acts as a prohormone capable of stimulating the liver and other estrogen target tissues which possess demethylating enzymes. It is pointed out that unlike estradiol the non-steroidal estrogens such as diethylstibestrol (DES) lack the ability to form two sets of catechol and guaicol metabolites, i.e. "C-2" and "C-4" metabolites with their different biological characteristics are not formed by DES.

Brain opiate receptor concentrations are increased in adult spontaneously hypertensive rats.

The saturable binding of 3H-naltrexone in the brains of eight week old spontaneously hypertensive rats (SHR) is about twice that measured in corresponding normotensive WKY rats. This increase is dependent on age since in three and four week old SHR and WKY rats no difference in binding is observed. Scatchard analysis of the saturation curves for the adult animals revealed that the change in binding is due to an increase in the number of binding sites and does not reflect a difference in binding affinity. The increase in opiate receptor content of SHR rats coincides with the appearance of elevated blood pressure in these animals, and supports a concept in which an interaction between the endorphins and the endocrine system may be involved in the mechanisms controlling hypertension.