Hormonal control of uterine contraction. Characterization od cyclic AMP-dependent membrane properties in the myometrium.

A mitochondria-free membrane fraction prepared from rat myometrium accumulated 45Ca2+ in the presence of oxalic acid and ATP. The rate of transport of Ca2+ into the membranous vesicles was increased by greater than 50% in the presence of 3',5'-cyclic AMP, but not by 2',3'-cyclic AMP or 5'AMP. Membrane ATPase activity was stimulated by Mg2+; slight additional stimulation was obtained in the presence of Na+ and K+ but not in the presence of Ca+2. Despite the cyclic AMP sensitivity of membrane ATPase activity, the absence of any effect of inhibitors of Ca2+-transport suggest it has little to do with Ca2+ accumulation by the membranes. Cyclic AMP-induced increase in Ca2+-transport and membrane ATPase activity was duplicated in vivo by incubating uteri in 10(-4)M isoproterenol prior to membrane isolation. Isoproterenol has been previously shown to increase myometrial cyclic AMP levels, and changes in Ca2+-transport by cell membranes in relation to intracellular cyclic AMP levels may be the mechanism through which hormones modulate uterine contractility.     

Cystic fibrosis testing in a referral laboratory: results and lessons from a six-year period

Background

The recent introduction of high throughput sequencing technologies into clinical genetics has made it practical to simultaneously sequence many genes. In contrast, previous technologies limited sequencing based tests to only a handful of genes. While the ability to more accurately diagnose inherited diseases is a great benefit it introduces specific challenges. Interpretation of missense mutations continues to be challenging and the number of variants of uncertain significance continues to grow.

Results

We leveraged the data available at ARUP Laboratories, a major reference laboratory, for the CFTR gene to explore specific challenges related to variant interpretation, including a focus on understanding ethnic-specific variants and an evaluation of existing databases for clinical interpretation of variants. In this study we analyzed 555 patients representing eight different ethnic groups. We observed 184 different variants, most of which were ethnic group specific. Eighty-five percent of these variants were present in the Cystic Fibrosis Mutation Database, whereas the Human Mutation Database and dbSNP/1000 Genomes had far fewer of the observed variants. Finally, 21 of the variants were novel and we report these variants and their clinical classifications.

Conclusions

Based on our analyses of data from six years of CFTR testing at ARUP Laboratories a more comprehensive, clinical grade database is needed for the accurate interpretation of observed variants. Furthermore, there is a particular need for more and better information regarding variants from individuals of non-Caucasian ethnicity.     

Record of Blue tilapia Oreochromis aureus (Steindachner, 1864) in the Eerste River catchment,Western Cape province,South Africa

Oreochromis aureus was imported from Israel into South Africa in 1959 but data on its current status in South Africa are lacking. Genomic DNA was extracted and the COI gene amplified at the South African Institute for Aquatic Biodiversity. The identity of the sequences and specimens was determined using the Barcode of Life Data Systems and GenBank. Morphological and genetic assessment demonstrated that 11 specimens collected from two farm dams in the Eerste River System, Western Cape province, were Oreochromis aureus. A MaxEnt model compiled using global distribution, rainfall and temperature data predicted that large areas of southern Africa were climatically suitable for this species, indicating considerable invasion debt in southern Africa. As a result, surveys to assess for the extent of the invasion in South Africa and eradication of existing populations, if feasible, are recommended management actions.     

Striped catfish (Pangasianodon hypophthalmus) could be suitable for coastal aquaculture

Salinity intrusion in the coastal freshwater rivers due to climate change and construction of the dam in the upstream rivers are alarming in aquaculture. Hence, an experiment was conducted to know the effects of salinity on growth performance, hemato‐biochemical parameters and erythrocytes structure in a commercially cultivable catfish species, striped catfish (Pangasianodon hypophthalmus). Firstly, median lethal concentration (LC₅₀) of salinity for striped catfish was determined and then the fish were exposed to three salinity conditions (4, 8 and 12‰) and a control (0‰). Fish were sacrificed at day 7, 14, 28 and 56 after the start of salinity exposure. The 96 hr LC₅₀ value was found to be 14.87‰. Salinity levels from freshwater to 8‰ showed optimal conditions with high survival rate and good growth performances of fish in terms of weight gain and specific growth rate (SGR). Interestingly, the lowest food conversion ratio (FCR) was found in 4‰ group. The hemoglobin (Hb) level and number of red blood cells (RBCs) were found to be decreased significantly in 8 and 12‰ compared to 0 and 4‰ at the initial days of exposure, while number of white blood cells (WBCs) and glucose level showed opposite scenario. Frequencies of ENA (erythrocytic nuclear abnormalities) and ECA (erythrocytic cellular abnormalities) were significantly increased with increasing salinities in the initial days of exposure. Overall, findings of the present study revealed that striped catfish might be suitable fish species for culture in the brackish water containing salinity up to 10‰.     

Characterization of photodamage to escherichia coli in optical traps

Optical tweezers (infrared laser-based optical traps) have emerged as a powerful tool in molecular and cell biology. However, their usefulness has been limited, particularly in vivo, by the potential for damage to specimens resulting from the trapping laser. Relatively little is known about the origin of this phenomenon. Here we employed a wavelength-tunable optical trap in which the microscope objective transmission was fully characterized throughout the near infrared, in conjunction with a sensitive, rotating bacterial cell assay. Single cells of Escherichia coli were tethered to a glass coverslip by means of a single flagellum: such cells rotate at rates proportional to their transmembrane proton potential (. J. Mol. Biol. 138:541-561). Monitoring the rotation rates of cells subjected to laser illumination permits a rapid and quantitative measure of their metabolic state. Employing this assay, we characterized photodamage throughout the near-infrared region favored for optical trapping (790-1064 nm). The action spectrum for photodamage exhibits minima at 830 and 970 nm, and maxima at 870 and 930 nm. Damage was reduced to background levels under anaerobic conditions, implicating oxygen in the photodamage pathway. The intensity dependence for photodamage was linear, supporting a single-photon process. These findings may help guide the selection of lasers and experimental protocols best suited for optical trapping work.