Presence or severity of Hashimoto's thyroiditis does not influence basal calcitonin levels: observations from CROHT biobank

PURPOSE

The influence of Hashimoto's thyroiditis (HT) on calcitonin (Ct) production is unresolved question. The aim of this study was to explore if basal Ct levels are influenced by the presence/severity of HT or correlated with clinical phenotypes of HT patients.

METHODS

We included 467 HT patients and 184 control participants, from Croatian Biobank of HT patients (CROHT), in this retrospective study. Calcitonin levels between HT patients and controls were compared using Mann-Whitney test. Ct levels between two subgroups of HT patients, divided by intake of levothyroxine (LT4) therapy, were additionally tested to take into account the illness severity. Spearman rank correlation test was used to analyze correlations between Ct levels and 14 relevant phenotypes.

RESULTS

We have not detected significant differences in median Ct levels between HT patients and controls (2.2 vs 2.35 pg/mL, respectively, P = 0.717) nor in-between two subgroups of HT patients (P = 0.347). We have not detected statistically significant correlations between Ct levels and clinical phenotypes, although we identified three weak nominal correlations: negative correlation of Ct with TgAb in all HT patients (r = - 0.1, P = 0.04); negative correlation of Ct with age in subgroup of HT patients without LT4 therapy (r = - 0.13, P = 0.04); positive correlation of Ct with BSA in subgroup of HT patients on LT4 therapy (r = 0.16, P = 0.042).

CONCLUSION

Our results suggest that HT patients of all disease stages preserve Ct production as healthy individuals and there is no need for Ct measurements in the absence of a nodule. Additional confirmation and clarification of observed nominal correlations are needed due to potential clinical relevance of TgAb and age-dependent Ct decrease in HT women.

Development of a valid and reliable instrument for the assessment of quality of life in parents of children with clefts

PURPOSE

Orofacial clefts are the most common congenital malformations that affect craniofacial structures. Studies show that they have a major influence on psychological development of the patient, and on their families. A review of the literature showed a lack of specific questionnaires for children and their parents. This study investigated the impact of orofacial clefts in children on the quality of life of their parents. In addition, the results of the treatment and the quality of work of the health team members involved in this process were evaluated.

MATERIALS AND METHODS

For the purpose of this study, an original questionnaire was made to analyse the effect of orofacial clefts in children who had undergone surgery on the quality of life of 73 of their parents. The questionnaire consisted of 28 simple statements, which were evaluated with a 5-degree Likert scale (from 1-fully disagree to 5-fully agree), did not require any specific additional clarification, and were easy to complete.

RESULTS

Analysis of areas of the questionnaire that applied to the parents, resulted in two subscales, parental social health and child social health, which had satisfactory Cronbach's coefficients (0.907 and 0.897, respectively). However, some issues had a relatively poor coefficient of internal consistency, which justified their expulsion from the final model of the parent questionnaire.

CONCLUSION

The questionnaire developed for this study comprised two subscales concerned with the social health of parents/respondents and the social health of adolescents, as perceived by the parents. It was a valid and reliable instrument, and it showed satisfactory quality of life for parents of adolescents with clefts.

Differential response of antioxidative systems of maize (Zea mays L.) roots cell walls to osmotic and heavy metal stress

An analysis of peroxidase and ascorbate oxidase activity, phenolic content and antioxidant capacity of isolated maize root cell walls was performed in controls and plants stressed with polyethylene glycol (PEG) or heavy metals, zinc or copper. Peroxidase activity (oxidative and peroxidative) was more pronounced in the ionic than in the covalent cell wall fraction. PEG induced an increase and Zn(2+) a decrease of both ionically bound peroxidase activities. In the covalent fraction, Cu(2+) decreased oxidative and increased peroxidative activity of peroxidase. Isoelectric focusing of ionically bound proteins and activity staining for peroxidase demonstrated increased intensities and appearance of new acidic isoforms, especially in Zn(2+) and PEG treatments. Most pronounced basic isoforms (pI ~ 7.5) in controls, decreased in intensity or completely disappeared in stressed plants. Ascorbate oxidase activity was significantly increased by PEG and decreased by Zn(2+) treatments, and highly correlated with peroxidase activity. Antioxidant capacity and total phenolics content increased in heavy metal-treated and decreased in PEG-treated plants. Analysis of individual phenolic components revealed p-coumaric and ferulic acids, as the most abundant, as well as ferulic acid dimers, trimers and tetramers in the cell walls; their quantity increased under stress conditions. Results presented demonstrate the existence of diverse mechanisms of plant response to different stresses.

Hydroquinone peroxidase activity of maize root mitochondria

The oxidation of hydroquinone with H(2)O(2) in the presence of mitochondria isolated from maize (Zea mays L.) roots was studied. The results indicate that a reduced form of quinone may be a substrate of mitochondrial peroxidases. Specific activities in different mitochondrial isolates, the apparent K (m) for hydrogen peroxide and hydroquinone, and the influence of some known peroxidase inhibitors or effectors are presented. Zymographic assays revealed that all mitochondrial peroxidases, which were stained with 4-chloro-1-naphthol, were capable of oxidizing hydroquinone. A possible antioxidative role of hydroquinone peroxidase in H(2)O(2) scavenging within the mitochondria, in cooperation with ascorbate or coupled with mitochondrial NAD(P)H dehydrogenases, is proposed.

Superoxide dismutase, peroxidase, and germin-like protein activity in plasma membranes and apoplast of maize roots

The analysis of plasma membranes from maize roots by native gel electrophoresis revealed the existence of Mn-containing 120 kDa and CuZn-containing 70, 40, and 15 kDa superoxide dismutase (SOD) isoform activities. Isoelectric focusing of the plasma membranes differentiated anionic SOD isoforms with a pI of about 5 and cationic SOD isoforms at pI 8.6. Solubilization of the plasma membrane proteins further separated the cationic SOD into pI 8.6, 8.2, 8.4, and 7.2 isoforms. Double staining for both SOD and peroxidase activities showed an overlap of these activities only in the case of the high-molecular-mass (ca. 120 kDa) isoforms. High-temperature treatments demonstrated that the 120 kDa isoform was active even at 100 degrees C, indicating that it was a germin-like protein with superoxide-dismutating activity, different from the peroxidase with a similar molecular mass and the lower-molecular-mass CuZn-containing superoxide dismutases. These results are compared to those obtained from whole-tissue extract and apoplastic fluid.

Superoxide synthase and dismutase activity of plasma membranes from maize roots

Superoxide synthase and superoxide dismutase activity have been monitored in isolated maize ( Zea mays) root plasma membranes spectrophotometrically by determination of nitro-blue tetrazolium and cytochrome c reduction, respectively. Superoxide production was induced by NADH and NADPH, with similar kinetics and approaching saturation at 0.06 mM in the case of NADPH and 0.1 mM in the case of NADH, with rates of 18.6 +/- 5.0 and 21.8 +/- 7.2 nmol/min. mg of protein, respectively. These activities exhibited a broad pH optimum between pH 6.5 and 7.5. Diphenylene iodonium inhibited about 25% (10 microM DPI) and 40% (100 microM DPI) of this activity, imidazole inhibited about 20%, while KCN, a peroxidase inhibitor, did not show any significant inhibition. Superoxide-dismutating activity was shown to occur in the same isolates and depended on the quantity of plasma membrane protein present. Growth of plants on salicylic acid prior to membrane isolation induced a rise in the activity of both of the enzymes by 20-35%, suggesting their coordinated action.

Involvement of plasma membrane redox system in the generation of trans-root electrical potential difference in excised maize root

Possible involvement of the plasma membrane bound redox system in the generation of the trans-root electrical potential difference (TRP) arising across 8 day old maize (Zea mays L. hybrid ZPSC704) roots was studied. Excised roots were exposed to artificial impermeable electron acceptors (potassium hexacyanoferrate III and potassium hexachloroiridate IV) in external solution, and TRP response, oxygen consumption rate, proton efflux and reduction of the electron acceptors were analyzed. The effect of hexacyanoferrate III (HCF III) was tested at three concentrations (0.1; 0.5 and 1.0 mmol/l), and hexachloroiridate IV (HCI IV) in the concentration range 10(-7)-5.10(-4) mol/l. Both electron acceptors depolarized the trans-root potential, an order of magnitude lower concentrations of hexachloroiridate producing a much more rapid depolarization of greater magnitude. The roots had a higher capacity to reduce 0.1 mmol/l hexachloroiridate than 1 mmol/l hexacyanoferrate. Also, an increased level of acidification induced by HCI IV than HCF III could be observed. The rate of oxygen consumption showed an increase of about 20% in both cases. These results prove that electron transplasma membrane transport process(es) contribute to the total trans-root electrical potential difference across an excised maize root.

Electrogenic proton pump in Nitella and the effect of calcium

The hyperpolarisation of the membrane potential in Characeae above that of the diffusion potential is explained by the operation of the electrogenic proton pump. We studied the interaction of calcium with the functioning of the pump. The membrane potential was measured using the standard microelectrode technique. An increase in the calcium concentration resulted in depolarisation, its magnitude increasing with lower proton concentrations. Calcium-induced membrane potential changes, tested in the concentration range of 0.25 mmol/l to 25 mmol/l, were greatest at 0.25 mmol/l CaCl2 and decreased with the increasing calcium concentration. Light-induced initial changes in the membrane potential also showed a dependence on the presence of calcium in the external medium. We conclude that calcium has a role in the regulation of the proton pump in Nitella.