Clinicopathological changes of uterine leiomyomas after GnRH agonist therapy.

OBJECTIVE: Gonadotrophin-releasing hormone agonist (GnRHa) has been commonly used for the medical treatment of prostate cancer, precocious puberty, endometriosis, adenomyosis and uterine leiomyomas. GnRHa therapy in cases of symptomatic uterine leiomyomas aims for the reduction of their size and remission of symptoms such as menometrorrhagia, causing a state of hypoestrogenemia. This is considered to be a helpful preoperative strategy in cases of large myomas, or anemia because of abnormal vaginal bleeding. The aim of this retrospective study was to examine the clinicopathological changes in uterine leiomyomas exposed to preoperative GnRHa therapy for two up to six months. MATERIALS AND METHODS: The study group consisted of 10 premenopausal patients who were treated with GnRHa prior to surgery. RESULTS: In all cases the size of leiomyomas was reduced after GnRHa therapy. A microscopic review of the surgical specimens showed increased cellularity and ischemic type of necrosis. CONCLUSION: Morphological changes of uterine leiomyomas are often associated with preoperative GnRH agonist therapy. The differential diagnosis from uterine leiomyosarcomas includes absence of mitotic activity.

The effect of MTHFR(C677T) genotype on plasma homocysteine concentrations in healthy children is influenced by gender.

OBJECTIVE: To explore the influence of gender, together with folate status, on the relation between the common methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and plasma total homocysteine (tHcy) concentrations in healthy children. DESIGN: Cross-sectional study by face-to-face interview. SETTING AND SUBJECTS: A total of 186 sixth-grade students participated from twelve randomly selected primary schools in Volos, Greece. METHODS: Fasting tHcy, folate, and vitamin B(12) were measured in plasma. The MTHFR genotypes were determined. Anthropometric and dietary intake data by 24-h recall were collected. RESULTS: Geometric means for plasma tHcy, plasma folate and energy-adjusted dietary folate did not differ between females and males. The homozygous mutant TT genotype was associated with higher tHcy only in children with lower plasma folate concentrations (<19.9 nmol/l, P = 0.012). As a significant gender interaction was observed (P = 0.050), we stratified the lower plasma folate group by gender and found that the association between the genotype and tHcy was restricted to males (P = 0.026). Similar results were obtained when folate status was based on estimated dietary folate. Specifically, only TT males that reported lower dietary folate consumption (<37 microg/MJ/day) had tHcy that was significantly higher than tHcy levels of C-allele carriers (P = 0.001). CONCLUSIONS: Under conditions of lower folate status (as estimated by either plasma concentration or reported dietary consumption), gender modifies the association of the MTHFR(C677T) polymorphism with tHcy concentrations in healthy children. SPONSORSHIP: Kellog Europe.

Photocatalytic reduction and recovery of mercury by polyoxometalates.

Photocatalytic reduction of mercury in aqueous solutions using PW12O40(3-) or SiW12O40(4-) as photocatalysts has been studied as a function of irradiation time, concentration of Hg(II), polyoxometalate, and organic substrate in the presence or absence of dioxygen. The photocatalytic cycle starts with irradiation of polyoxometalate, goes through the oxidation of, for instance, propan-2-ol (used as sacrificial reagent), and closes with the reoxidation of reduced polyoxometalate by Hg2+ ions. Mercury(II) is reduced to mercury(I) and finally to Hg(0) giving a dark-gray deposit, following a staged one-by-one electron process and a first-order kinetics in [Hg2+]. The process is slightly more efficient in the absence of dioxygen, while the increase of either catalyst or propan-2-ol concentration results in the augmentation of the rate of reduction till a certain point where it reaches a plateau. The results show that this method is suitable for a great range of mercury concentration from 20 to 800 ppm achieving almost complete recovery of mercury up to nondetected traces (<50 ppb). In addition, this homogeneous process demonstrates advantages such as the lack of necessity for separation of the zero state metal from the catalyst and ensures that the precipitation of metal will not poison the catalyst or hinder its photocatalytic activity.

Photocatalytic reduction and recovery of copper by polyoxometalates.

A series of polyoxometalates PW12O40(3-), SiW12O40(4-), and P2Mo18O62(6-) have been used as photocatalysts for recovery of copper and production of fine metal particles. The process involves absorption of light by polyoxometalates, oxidation of an organic substrate, for instance, propan-2-ol as sacrificial reducing reagent, and reoxidation of the reduced polyoxometalates by Cu2+ ions, closing the photocatalytic cycle. Copper(II) ions are reduced to copper(I) and finally to zero-state particles in a 2-electron process, as also suggested by the half-order dependence. Increase of catalyst or propan-2-ol concentration, or both, accelerates the photodeposition of copper until a saturation value is reached. The method is operational at a wide range of copper concentrations varying from 3 to 1300 ppm, leading to very low final concentrations (<0.2 ppm). The presence of dioxygen suppresses the initiation of copper recovery, though the process is equally effective after dioxygen is consumed. The process is independent of pH within the range 0.3-5.0. Addition of ClO4-, NO3-, or CH3COO- has no effect on the removal of copper ions. Chloride ions retard the enhancement of copper precipitation through stabilization of copper(I). This homogeneous, polyoxometalate-based process exhibits some benefits in comparison with the semiconductor-based (heterogeneous) recovery of metals: The final zero-state metal particles are obtained in pure form. No separation from the catalyst is needed, and moreover, the process is catalytic as the photodeposited metal particulates do not hinder the photocatalytic action of polyoxometalate anions.

Sonolytic, photolytic, and photocatalytic decomposition of atrazine in the presence of polyoxometalates.

Aqueous solutions of atrazine [2-chloro-4-(isopropylamino)-6-(ethylamino)-s-triazine] (CIET) decompose upon illumination with a low-pressure Hg-arc lamp (254 nm). However, no decomposition takes place with lambda > 300 nm. On the other hand, addition of polyoxometalates (POM), PW12O40(3-) or SiW12O40(4-), into a solution of atrazine photodecomposes the substrate within a few minutes (cutoff fiter 320 nm). Ultrasound (US) treatment also decomposes aqueous solutions of atrazine within a few minutes. Both methods, sonolysis and photolysis with POM, give common intermediates, namely, 2-hydroxy-4-(isopropylamino)-6-amino-s-triazine (OIET), 2-chloro-4-(isopropylamino)-6-amino-s-triazine (CIAT), 2-chloro-4-amino-6-(ethylamino)-s-triazine (CAET), 2-hydroxy-4,6-diamino-s-triazine (OAAT), and 2-hydroxy-4-hydroxy-6-amino-s-triazine (OOAT) among others. The final products for both methods, US and photolysis with POM, were cyanuric acid (OOOT), NO3-, Cl-, CO2, and H2O. OOOT showed no signs of decomposition by sonication and/or photolysis with POM. It also resisted degradation upon photolysis with plain UV light (254 nm). However, it has been reported to decompose upon photolysis with lambda > 200 nm. Combination of US and photolysis with POM produces only a cumulative effect.

Increased beta-endorphin but not Leu-enkephalin in plasma due to preoperative stress.

The levels of beta-endorphin and Leu-enkephalin were measured in the plasma of 23 children (16 male, 7 female) who were admitted to the Children's Hospital for elective (non-emergency) surgery, adenoidectomy and/or tonsillectomy. Two blood samples were obtained preoperatively. The first sample was taken during admission to the hospital; the second on 24 h later and just 5 min before the operation, without pre-medication or narcosis. beta-endorphin and Leu-enkephalin levels were measured using a RIA method after solid phase extraction of the samples. Mean beta-endorphin concentrations during admission to the hospital were 11.77 +/- 9.36 pg/ml. Twenty four hours later, and just 5 min before surgery, the mean levels of beta-endorphin were increased to 27.45 +/- 16.66 pg/ml. A statistically significant increase (t-value = -5.42) was found for beta-endorphin levels 5 min before the operation compared with 24 h earlier (2-tail probability p < 0.0001). The Wilcoxon matched-pairs signed-ranks-test also showed p < 0.0001 (Z = -4.197). In contrast, Leu-enkephalin levels remained unchanged. The mean values were 11.44 +/- 1.49 pg/ml on the day of admission, and 12.11 +/- 2.08 pg/ml 5 min before the operation. We did not find statistically significant differences between the paired samples (t-value = -1.53, 2-tail probability p = 0.139). The increase in beta-endorphin could be the result of preoperative anxiety about the narcosis and surgery.

Raised beta-endorphin serum levels in children with atopic dermatitis and pruritus.

Atopic dermatitis (AD) is a pruritic cutaneous inflammatory condition. As pruritus and pain are very close symptoms, we determined the beta-endorphin serum concentrations in 21 atopic children with pruritus (group A) and 20 children with healed AD without pruritus (group B). Twenty-five healthy school children were the control group. The beta-endorphin serum concentrations (14.95 +/- 2.75 pmol/l) in group A were statistically (P < 0.001) elevated in our patients compared to controls (8.85 +/- 2.39 pmol/l) whereas these in group B were not elevated (9.4 +/- 2.46 pmol/l). We suggest that the elevated beta-endorphin concentrations in atopic patients with pruritus confirm the hypothesis that there is an increased activity of their opioid system and that an opioid antagonist might block itching which is their major clinical symptom.