Coexpressed subunits of dual genetic origin define a conserved supercomplex mediating essential protein import into chloroplasts

In photosynthetic eukaryotes, thousands of proteins are translated in the cytosol and imported into the chloroplast through the concerted action of two translocons-termed TOC and TIC-located in the outer and inner membranes of the chloroplast envelope, respectively. The degree to which the molecular composition of the TOC and TIC complexes is conserved over phylogenetic distances has remained controversial. Here, we combine transcriptomic, biochemical, and genetic tools in the green alga Chlamydomonas (Chlamydomonas reinhardtii) to demonstrate that, despite a lack of evident sequence conservation for some of its components, the algal TIC complex mirrors the molecular composition of a TIC complex from Arabidopsis thaliana. The Chlamydomonas TIC complex contains three nuclear-encoded subunits, Tic20, Tic56, and Tic100, and one chloroplast-encoded subunit, Tic214, and interacts with the TOC complex, as well as with several uncharacterized proteins to form a stable supercomplex (TIC-TOC), indicating that protein import across both envelope membranes is mechanistically coupled. Expression of the nuclear and chloroplast genes encoding both known and uncharacterized TIC-TOC components is highly coordinated, suggesting that a mechanism for regulating its biogenesis across compartmental boundaries must exist. Conditional repression of Tic214, the only chloroplast-encoded subunit in the TIC-TOC complex, impairs the import of chloroplast proteins with essential roles in chloroplast ribosome biogenesis and protein folding and induces a pleiotropic stress response, including several proteins involved in the chloroplast unfolded protein response. These findings underscore the functional importance of the TIC-TOC supercomplex in maintaining chloroplast proteostasis

Spectrophotometric multicomponent determination of sunset yellow, tartrazine and allura red in soft drink powder by double divisor-ratio spectra derivative, inverse least-squares and principal component regression methods

Double divisor-ratio spectra derivative (graphical method), classical least-squares and principal component. regression (two numerical methods) methods were developed for the spectrophotometric multicomponent analysis of soft drink powders and synthetic mixtures containing three colorants without any chemical separation. The graphical method is based on the use of derivative signals of the ratio spectra using double divisor. In this method, the linear determination ranges were 2-8 mug ml(-1) sunset yellow, 4-18 mug ml(-1) tartrazine and 2-8 mug ml(-1) allura red in 0.1 M HCl. In the numerical methods, a training set was randomly prepared by using 18 samples containing between 0 and 8 mug ml(-1) of sunset yellow, 0-18 mug ml(-1) of tartrazine and 0-8 mug ml(-1) of allura red. The chemometric calibrations were calculated by using the prepared training set and its absorbances at seven points (from 375.0 to 550.0 nm) in the spectral region 325-584 nm. The proposed methods were validated by using synthetic ternary mixtures and applied to the simultaneous determination of three colorants in soft drink powders. The obtained results were statistically compared with each other. (C) 2002 Elsevier Science B.V. All rights reserved

Sexual myths during pregnancy: a comparative study

This study was conducted to determine the prevalence of sexual myths during pregnancy among pregnant women in Turkey and Iran and to compare the similarities and differences between the countries. This is a comparative and descriptive study. The sample included 200 pregnant women from Turkey and Iran. The data were collected using the Descriptive Information Form and Sexual Myths During Pregnancy Form. It was determined that the women in Turkey agreed more with statements, such as 'the infant feels sexual intercourse', 'the infant becomes happy and healthy', 'sexual intercourse during pregnancy is safe'. As for pregnant women in Iran, it was determined that they were more hesitant to agree with statements, such as 'sexual intercourse is a sin' and 'sexual intercourse causes infections'. In both countries, education on sexuality during pregnancy is needed to eliminate information deficiencies.Impact Statement What is already known on this subject? Sexual myths during pregnancy are exaggerated beliefs with no scientific accuracy. These beliefs affect the attitudes and behaviours related to sexuality during pregnancy. What do the results of this study add? This study has revealed that sexual myths during pregnancy are common among pregnant women in Turkey and Iran, and there are similarities and differences between the countries in terms of myths. What are the implications of these findings for clinical practice and/or further research? Healthcare professionals should question pregnant women about sexuality during pregnancy, identify missing and incorrect information, and provide counselling

Effects of various freezing and cooking processes on the residues of sulfamethazine in broiler tissues

This study was conducted to investigate the effects of frying, boiling and freezing processes on sulfamethazine (SMZ) residues in chick breast meat and liver. Chicks were fed with feed not containing sulfonamide residues for 30 days. After 30 days, the suspensions of SMZ (110 mg/kg) were given to 10 chicken by gavage to craw once daily for 5 days. After 35 day, all animals were slaughtered and their breast meat and liver were taken. The part of the tissues were stored in -20 degrees C freezer for 30 and 45 days. The levels of SMZ in raw, grilled and boiled and freezed tissues were determined by HPLC-DAD detector. As a result of the study, it has been determined that, boiling and grilling processes reduced the residues of SMZ at different rates in broiler tissues; storing in the deep freezer did not cause significant changes on drug residues

Effects of Various Cooking and Freezing Processes on the Residues of Sulfachlorpyridazine-Trimethoprim Combination in Broiler Tissues

This study was conducted to determine the effects frying, boiling and freezing processes on the levels of sulfachlorpyridazine (SCP) and trimethoprim (TMP) in broiler chest meat and liver. Male broiler chicks were assigned to two groups as control and treatment groups. Animals were fed on commercial diet not containing SCP and TMP for 35 days. At 30th day, experimental group received suspensions of SCP-TMP mixture (30 mg/kg SCP and 6 mg/kg TMP) via craw by gavage once daily for 5 days. At the end of 35th day, the chickens were sacrified and right chest tissue and the liver were taken out. A portion of the tissues were stored in -20 degrees C freezer for 30 and 45 days. After sacrifiying, the raw tissues were exposed to frying and boiling processes. SCP and TMP analysis of tissues were performed by HPLC-DAD detector and reverse phase column. In conclusion, it has been determined that boiled and grilled processes caused a reduction of SCP and TMP residues at different rates in broiler tissues; while storing in the deep freezer did not cause a significant change on SCP and TMP residues