Interleukin-6 and C-Reactive Protein: their association with vitamin D in women with recurrent infections of reproductive system.

Aerobic bacteria can colonize the female reproductive system with harmful effects, which may lead to miscarriages, premature deliveries or continue of its growing to cause adverse reproductive systems issues. Increasing in the levels of inflammatory markers may be considered a herald of danger. High vaginal swabs were obtained from 85 women. Of these, 67 patients were suffering recurrent vaginitis and symptoms such as itching, irritation, burning, and vaginal discharged, and 18 apparently healthy controls. Swabs were cultured in a suitable media and the cultivated bacteria were diagnosed in the hospital's laboratory. At the same time of collecting the vaginal swabs, 5 ml of venous blood was withdrawn from the patients and controls. An ELISA method was applied to measure the levels of inflammatory cytokines and concentration of vitamin D. The bacterial growth showed six species of isolated bacteria, which were Staphylococcus aureus, Streptococcus spp., E. coli, S. non aureus, Proteus spp. and Klebsiella spp. The first three species were the most prevalent bacteria, and the serum levels of C reactive protein (CRP) and IL-6 were high in female patients infected with these bacteria. CRP was significantly elevated in sera of the patient's group (P= 0.016), while the increase in IL-6 was not significant. Vitamin D was correlated negatively with IL-6 and positively with CRP, but the correlations did not reach statistical significance. In conclusion, rising of CRP could be an expected result to the bacterial colonizing the reproductive system while IL-6 may develop significantly when the aerobic vaginitis continues until triggering one of the infertility issues.

Exploring the acid-catalyzed substitution mechanism of [Fe4S4Cl4](2-).

Kinetic studies on the acid-catalyzed substitution reactions of the teminal chloro-ligands in [Fe4S4Cl4](2-) by PhS(-) in the presence of the acids NHR3(+) (R = Me, Pr(n) or Bu(n)) are reported. Although these acids have very similar pKas (17.6-18.4) the reactions show a variety of different kinetics, some of which are inconsistent with a mechanism involving simple protonation of the cluster followed by substitution of a terminal ligand. The observed behaviour is more consistent with the recently proposed mechanism in which Fe-(µ3-SH) bond elongation/cleavage occurs upon protonation of a µ3-S, and suggests that both the acidity and bulk of the acid is important in the protonation step. Other studies have determined the activation parameters (ΔH(‡) and ΔS(‡)) for both the protonation and substitution steps of the acid-catalyzed substitution reactions of [Fe4S4X4](2-) (X = Cl or SEt). A significantly negative ΔS(‡) is observed for the substitution steps of both clusters indicating associative pathways. This is inconsistent with earlier interpretation of the kinetics of these reactions (based exclusively on the dependence of the rate on the concentration of nucleophile) and indicates that there is no dissociative substitution mechanism and the pathway associated with a zero order dependence on the concentration of PhS(-) involves associative substitution with the solvent (MeCN) being the nucleophile.

Binding small molecules and ions to [Fe4S4Cl4](2-) modulates rate of protonation of the cluster.

The mechanism of the acid-catalyzed substitution reaction of the terminal chloro-ligands in [Fe4S4Cl4](2-) by PhS(-) in the presence of NHBu(n)3(+) involves rate-limiting proton transfer from NHBu(n)3(+) to the cluster (k0 = 490 ± 20 dm(3) mol(-1) s(-1)). A variety of small molecules and ions (L = substrate = Cl(-), Br(-), I(-), RNHNH2 (R = Me or Ph), Me2NNH2, HCN, NCS(-), N3(-), Bu(t)NC or pyridine) bind to [Fe4S4Cl4](2-) and this affects the rate of subsequent protonation of [Fe4S4Cl4(L)](n-). Where the kinetics allow, the equilibrium constants for the substrates binding to [Fe4S4Cl4](2-) (K(L)) and the rates of proton transfer from NHBu(n)3(+) to [Fe4S4Cl4(L)](n-) (k) have been determined. The results indicate the following general features. (i) Bound substrates increase the rate of protonation of the cluster, but the rate increase is modest (k/k0 = 1.6 to ≥72). (ii) When K(L) is small, so is k/k0. (iii) Binding substrates which are good σ-donors or good π-acceptors lead to the largest k/k0. This behaviour is discussed in terms of the recent proposal that protonation of [Fe4S4Cl4](2-) at a µ3-S, is coupled to concomitant Fe-(µ3-SH) bond elongation/cleavage.