Vugar Aliyev

The effects of metallothionein 2A polymorphism on placental cadmium accumulation: Is metallothionein a modifiying factor in transfer of micronutrients to the fetus?

Metallothionein affects the metabolism, transport and storage of micronutrients such as zinc, copper and iron, and the detoxification of heavy metals, especially cadmium. Cd is a common, highly toxic environmental pollutant that accumulates in human placenta, elevated concentrations of which are associated with impaired zinc transfer to the fetus. This prospective study investigated the effects of metallothionein 2A (MT2A) −5 A/G single nucleotide polymorphism on the accumulation of Cd in human placenta and micronutrient transfer to the fetus in 95 pregnant women and their newborns. Venous blood from the mother was collected to investigate Cd, Zn, Cu, Fe levels and MT2A polymorphism. Cord blood from the neonate and placenta was collected for metal levels. MT2A polymorphism was determined by the standard PCR‐restriction fragment length polymorphism technique. Metal levels were analyzed by Atomic Absorption Spectrometry (AAS). Maternal blood Cd levels were statistically higher for mothers with a heterozygote genotype compared with a homozygote genotype (P < 0.05). In contrast, placental Cd levels were significantly higher in mothers with a homozygote rather than a heterozygote genotype (P < 0.05). No difference existed in cord blood Cd, Zn and Cu levels. However, cord blood Fe levels of newborns with heterozygote genotype mothers were higher than in others. Placental Cd levels of heterozygote genotype mothers were negatively associated with Zn in cord blood. Cd exposure at environmental levels may be associated with alteration of the umbilical cord micronutrient levels for newborns with mothers of a heterozygote genotype. Copyright

Exposure to mercury among dental health workers in Turkey: correlation with amalgam work and own fillings.

Purpose: To investigate the current status of exposure to mercury (Hg) among dental health workers in Turkey. Methods: A total of 115 persons working in the same hospital were included in the study and were divided into three groups. Group 1 consisted of 67 dentists; group 2 consisted of 21 dental personnel who work with amalgam, and group 3 consisted of 27 control subjects who work in the same hospital but are non-dental personnel. The number of amalgam fillings that have been made by the dentists and the number of own fillings of the subjects were recorded. Results: Plasma Hg levels were found to be 3.76 ± 1.84, 3.54 ± 1.83, and 2.69 ± 0.97 µg/L in groups 1, 2, and 3, respectively. Hg concentrations in group 1 were significantly higher than the control group. There was no significant difference between groups 1 and 2. The number of amalgam fillings made by the dentists in the previous year correlated significantly with plasma Hg levels (r = 0.378, p < 0.01). There was no significant correlation between the own amalgam fillings in the teeth of the subjects and Hg levels. Conclusion: Preventive measures for protection from exposure to Hg are necessary for occupational health in dentistry and proper industrial hygiene rules should be emphasized to avoid contamination during work.

Effects of the interleukin-6 (IL-6) polymorphism on toxic metal and trace element levels in placental tissues

The placenta is a crucial organ of fetal origin that functions in providing nutrients to the fetus from the mother. During pregnancy, the need for essential micronutrients, such as Fe and Zn, increases due to the requirements of the growing fetus. Maternal Fe deficiency induces an increase in Cu levels and can also affect cytokine levels in the placenta. On the other hand, Cu deficiency, although not as common, can also have destructive effects on the fetus. Interleukin-6 (IL-6) is a pleiotropic cytokine with a wide range of biological activities, including such as immune responses, acute-phase reactions, and inflammation. The placenta produces a significant amount of IL-6 during pregnancy. The effects of the IL-6 -174 G/C single nucleotide polymorphism (SNP) on IL-6 gene transcription and on plasma cytokine levels were assessed in the present study. We investigated the association between the IL-6 -174 G/C polymorphism and trace element/toxic metal levels in placental tissues. For the purposes of this study, 95 healthy volunteers were evaluated. Presence of the IL-6 polymorphism was determined using the standard polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique, and metal levels were analyzed by atomic absorption spectrometry (AAS). Based on our data, there were no significant associations between the IL-6 -174 G/C polymorphism and Pb, Cd, Fe, or Zn levels in the placental tissues (p>0.05), but a statistically significant association was detected between the polymorphism and Cu levels (p=0.016). We determined that the mean Cu levels in the placental tissues from individuals with GG, GC and CC genotypes were 5.62±1.98, 6.22±3.22 and 8.00±1.32 ppm, respectively, whereas the overall mean Cu level from the placental tissues was 5.98±2.51 ppm.