[Perinatal risk factors for infection in the newborn. Multicenter clinico-epidemiologic investigation]. / Fattori perinatali di rischio d'infezione nel neonato. Indagine multicentrica clinico epidemiologica.

UNLABELLED: The neonate, in particular if preterm, has a specific immunological system that makes him/her more susceptible to infections which are still a major cause of mortality and morbidity. The early onset infective patterns are often vertically transmitted from the mother to the fetus in the perinatal period. Some mother conditions like genitourinary infections, pre-delivery fever, PROM, pPROM, preterm delivery, abortions, fetal demise are important neonatal risk factors. The role of these factors as causes of early onset neonatal infections was evaluated by an Italian multicentric epidemiologic investigation supported by the MIUR. Mothers admitted to obstetrician hospitals for parturition were studied in a case control retrospective analysis. Mothers presenting with the selected risk factors were the cohort of cases while the admissions without risk factors next to each case represented the controls. The following risk factors were considered for analysis: 2nd trimester abortion, PROM, pPROM, preterm delivery and fetal demise. Eight hospitals entered the multicentric research and 29610 patients have been analyzed: 2466 PROM, 478 pPROM, 946 preterm delivery, 244 abortions, 133 fetal demise. Every woman received a microbiological screening by cervico-vaginal and rectal swab and/or urine culture. As much as 3892 cases from the University Hospitals of Parma and Torino concern, the cervicovaginal swab was positive in 76.5% pPROM, in 50.6% PROM and 50.5% preterm deliveries. The positivity of the swabs showed statistical relevance in cases compared to controls. In cases presenting with abortion the frequency of positive cultures (44.1%) was higher than the controls, but it did not reach statistical relevance. Conversely, positivity of cultures was lower in cases with fetal demise than control group but without statistical difference. In the cohort of 675 women selected from our Institute (University of Parma) the overall rate of positivity of cervico-vaginal swabs was about 44% and only one germ was isolated in 94.6% cases: 49,8% Gram positive and negative, 14.1% Streptococcus hemolyticus B group, 34.7% Candida. The rate of cultural tests performed before delivery was statistically higher in cases than controls (74.3% vs 23.2%, p < 0.001). Furthermore 14.3% newborns from mothers in the case group and 2.3% newborns from mothers in the control group were admitted to the neonatal care unit. Among them 8.4% and 1.2% respectively needed antibiotics while 0.4% and 0.2% respectively presented with early onset infection. Ear swabs were performed in 48,8% of infants born to mothers from the case group and in 26.9% of infants born to mothers from the control group, in 6.5% and in 2.9% respectively were the skin swabs performed as well. No statistical difference was met. The choice to perform cultural examinations was statistically higher in cases than controls, but the positivity rate was similar in both groups, perhaps because of a more specific choice in the control group. CONCLUSION: our data confirm the relationship between infections and preterm delivery, PROM, pPROM and support the hypothesis that infections might be the cause of these conditions and not simply an association. A prompt maternal microbiological control during pregnancy and delivery, especially in women presenting with known risk factors, gives the possibility to do early diagnostic-therapeutic interventions and to minimize the frequency and severity of early sepsis in newborns.

The binding ability of iron bonded to porphodimethene: structural, magnetic, and electronic relationship to iron porphyrin complexes.

The availability of the parent compound, meso-hexaethylporphodimetheneiron(II), [(Et6N4)Fe] (2), of this report results from a novel synthetic methodology that makes [Et6N4Li2] (1) easily available. The major focus is on how the axial positions, which are the key reactive sites in metalloporphyrins, and the electronic configuration of the metal can be affected by the breakdown of the aromaticity of the porphyrin skeleton and by the nonplanar conformation of the ligand. DFT calculations indicate a 3B1(dz2)1(dyz)1 ground state for 2 versus the 3A2(dxz)1(dyz)1 ground state in the porphyrin analogue. The intermediate-spin state (S = 1) of 2 changed drastically upon addition of one or two axial ligands, as hexacoordination is preferred by iron(II). The hexacoordinate complexes [(Et6N4)Fe(L)(L')] (L = L' = THF, 3; L = L' = Py, 4; L = PhNO, L' = Py, 14) have been isolated and structurally characterized. Strong-field ligands lead to a low-spin diamagnetic state for iron(II), namely for complexes 4-7, 9, and 14, whereas 3 is a typical d6 high-spin complex, as is the pentacoordinate [(Et6N4)Fe(CN)]Bu4N (8). The structural analysis showed common features for 6, 7, 9, and 14: i) a small displacement of the metal from the N4 plane, and ii) an N4 cavity, larger than that in the corresponding porphyrins, affecting the Fe-N bond lengths. The 1H NMR spectrum is quite diagnostic of the two-fold symmetry in the diamagnetic hexacoordinate complexes, revealing either a D2h or a C2v symmetry. The CO stretching frequency (1951 cm(-1)) in complex 6 probes the good electron density at the metal. The one-electron oxidation of 2 led to pentacoordinate iron(III) derivatives [(Et6N4)Fe(Cl)] (10), [(Et6N4)2Fe2(mu-O)] (11), and [(Et6N4)2Fe2(mu-p-OC6H4-O)] (12). Complex 10 is a typical high-spin iron(III) (5.85muB at 298 K), while 11 and 12 behave as antiferromagnetic coupled iron(III) (J = -9.4cm(-1), 12, and J = -115cm(-1), 11). In complexes 10, 11, and 12 iron is sitting in a quite distorted square pyramidal geometry, in which the ligand displays a very distorted roof conformation with different degrees of ruffling. Distinctive structural and magnetic features have been found for the nitrosyl derivative [(Et6N4)Fe-NO], which has a low-spin state (S = 1/2) and the following structural parameters: Fe-N-O, 147.3(2) degrees; Fe-N, 1.708(2) A; N-O, 1.172(3) A. A comparative structural, magnetic, and theoretical analysis of the compounds listed above has been made with the analogous porphyrin derivatives. The detailed structural investigation has been mapped through the X-ray analysis of 2, 7, 8, 9, 11, 13, and 14.

Binding and redox properties of iron(II) bonded to an oxo surface modeled by calix[4]arene.

The syntheses of the parent compounds [(p-Bu(t)-calix[4]-(O)2(OR)2)Fe-L] [R = Me, L = THF, 5; R = Bu(n), L = THF, 6; R = PhCH2, L = THF, 7; R = SiMe3, L = none, 8] have been performed by reacting the protonated form of the dialkylcalix[4]arene with [Fe2Mes4] [Mes = 2,4,6-Me3C6H2]. All of them undergo one-electron oxidative functionalization. By use of different oxidizing agents, the following iron(III) derivatives have been obtained: [(p-Bu(t)-calix[4]-(O)2(OR)2)Fe-X] [X = Cl, R = Me, 9; X = I, R = Me, 10] and [(p-Bu(t)-calix[4]-(O)2(OR)2)2Fe2(mu-X] [X = O, R = Me, 11; X = O, R = Bu(n), 12; X = S, R = Me, 13], 9 and 10 being particularly appropriate for a further functionalization of the metal. The last three display typical antiferromagnetic behavior [J = -78.6 cm-1, 11; J = -64.1 cm-1, 13]. In the case of 7 and 8, the reaction with O2 led to the dealkylation of one of the alkoxo groups, with the formation of a dimeric iron(III) derivative ([mu-p-Bu(t)-calix[4]-(O)3(OR))2Fe2] [R = PhCH2, 14; R = SiMe3, 15] [J = -9.8 cm-1]. The reaction of the parent compounds with ButNC and diazoalkanes led to the formation of [Fe=C] functionalities supported by a calix[4]arene oxo surface. The following compounds have been isolated and characterized: ([p-Bu(t)-calix[4]-(O)2(OR)2)Fe=CNBut] [R = SiMe3, 16, nu CN = 2175 cm-1], ([p-Bu(t)-calix[4]-(O)2(OR)2)Fe=CPh2] [R = Me, 17; R = PhCH2, 18; R = SiMe3, 19]. The three carbene complexes 17-19 display quite an unusual high-spin state, which is a consequence of the formation of a weak pi interaction between the metal and the carbene carbon, as confirmed by the extended Hückel calculations. The carbene functionality has been removed from the iron center in the reaction with O2 and HCl. The proposed structures have been supported by X-ray analyses of complexes 8, 9, 12, 14, 16, 17, and 19.