Biomedical subjects

R Amini

Publications and source records attributed to R Amini.

4 recordsLinked to original sources

PubMed2001

Kinetic spectrophotometric determination of thiocyanate based on its inhibitory effect on the oxidation of methyl red by bromate.

A kinetic spectrophotometric method for measuring thiocyanate is described. The proposed method is based on the inhibitory effect of thiocyanate on the oxidation of Methyl Red by bromate in the presence of nitrite, which was monitored at 520 nm. The variables affecting the rate of the reaction were investigated and the optimum conditions were established. Thiocyanate can be measured in the range of 0.05-1.1 microg ml(-1) with a detection limit of 0.025 microg ml(-1). This method has been used to determine trace thiocyanate in urine and tap water samples.

Absorption↗

PubMed1999

Control of hippocampal morphogenesis and neuronal differentiation by the LIM homeobox gene Lhx5.

The mammalian hippocampus contains the neural circuitry that is crucial for cognitive functions such as learning and memory. The development of such circuitry is dependent on the generation and correct placement of the appropriate number and types of neurons. Mice lacking function of the LIM homeobox gene Lhx5 showed a defect in hippocampus development. Hippocampal neural precursor cells were specified and proliferated, but many of them failed to either exit the cell cycle or to differentiate and migrate properly. Lhx5 is therefore essential for the regulation of precursor cell proliferation and the control of neuronal differentiation and migration during hippocampal development.

Animals↗

PubMed1996

Serum prolactin concentrations are elevated after syncope.

The distinction between syncope and epileptic seizures is a common clinical diagnostic problem. Elevated serum prolactin (PRL) concentrations are used to help differentiate epileptic from nonepileptic attacks such as pseudoseizures. Reports of PRL concentrations following syncope have been variable. To determine whether PRL rises after syncope, we measured serum PRL concentrations during a 45-minute passive 60-degree head-up tilt in 21 patients with a history of near-fainting or syncope. Head-up tilt triggered hypotension (mean arterial pressure 51 mm Hg, 95% CI = 45-57) with syncope in 11 patients. PRL concentrations were elevated ( > 19 ng/mL) and reached a maximum within the first 30 minutes after tilt-induced syncope in nine patients (PRL supine: 11 ng/mL, 95% CI = 7-15, vs. PRL after syncope: 52 ng/mL, 95% CI = 36-67; a greater than fourfold rise), while they remained unchanged in 10 patients who had a normal response to head-up tilt (PRL supine: 6 ng/mL, 95% CI = 5-8, vs. maximum PRL while upright: 8 ng/mL, 95% CI = 6-10). The findings indicate that elevated PRL concentrations are present after hypotensive syncope and are of little use in differentiating such syncope from epileptic seizures.

Aged↗

PubMed1987

Heterologous enzyme function in Escherichia coli and the selection of genes encoding the catalytic RNA subunit of RNase P.

The gene for the catalytic RNA subunit of RNase P has been isolated from several Enterobacteriaceae by complementation of an Escherichia coli strain that is temperature-sensitive for RNase P activity. The selection procedure relies on the ability of the heterologous gene products to function enzymatically in E. coli. This procedure obviates the need for positive results in DNA blot hybridization experiments or for the purification of holoenzyme to identify the RNA component of RNase P and its corresponding gene from organisms other than E. coli. Comparisons of the variations in sequences provide the basis for a refined two-dimensional model of the secondary structure of M1 RNA.

Base Sequence↗