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S Loric

Publications and source records attributed to S Loric.

45 records · Page 3Linked to original sources
PubMed1994

The mouse 5-HT2B receptor: possible involvement in trophic functions of serotonin.

The novel serotonin receptor 5-HT2B shows the highest homology to the 5-HT2 family of receptors. The pharmacological profile of membranes from 5-HT2B cDNA stably transfected LMTK- cell line, corresponds to a new 5-HT2-like receptor named 5-HT2B, although some difference exists between the mouse and rat pharmacology. A similar pharmacological profile is detected on the immortalized teratocarcinoma-derived cell line 1C11 upon 2 days of serotoninergic differenciation by cAMP. In both cell lines, the analysis 125I-DOI binding reveals the presence of a single class of sites, the affinity of which is one order of magnitude lower than the one reported for the 5-HT2A receptor. This demonstrates that the 5-HT2B receptor is functionally expressed before the complete serotoninergic differentiation of 1C11 cells. These observations are in good agreement with the presence of 5-HT2B mRNA in early mouse embryonic development. Furthermore, the major sites of 5-HT2B mRNA embryonic expression are in the heart, and in the neural fold before the closure of the neural tube. Therefore, this receptor could account at least in part for the trophic functions attributed to the 5-HT2-like receptors.

Animals↗
PubMed1992

New mouse 5-HT2-like receptor. Expression in brain, heart and intestine.

A novel member of the family of G protein-coupled receptors has been isolated from a mouse brain cDNA library by screening with polymerase chain reaction (PCR) generated fragment of mouse genomic DNA amplified using degenerated primers. Sequence comparison demonstrates that the encoded protein sequence shows the highest homology to the 5-HT2 family of receptors. The pharmacological profile of membranes from COS cells transfected with this cDNA, corresponds to a new 5-HT2-like receptor that we propose to call 5-HT2C. Its major sites of expression are in the mouse intestine and heart, also with detectable expression in brain and kidney. We speculate that it could account at least in part for the 'atypical' functions attributed to the 5-HT1C/5-HT2 receptors.

Amino Acid Sequence↗
PubMed1989

Immunochemical characterization of corticosteroid-binding globulin in human bronchoalveolar fluid.

The corticosteroid-binding globulin (CBG) is a plasma protein which is present both in liver, where it is mainly synthesized, and in cells of different target tissues for glucocorticoids. Using monospecific antibodies raised against human CGB, we could demonstrate the antigenic identity of the protein in human bronchoalveolar fluid. We found that the bronchoalveolar fluid/serum concentration ratio of CBG was similar to that of albumin. Since albumin is not synthesized in pulmonary cells, it was concluded that, in healthy human, CBG enters bronchoalveolar fluid by diffusion through alveolar cells. It is suggested that the expression of the CBG gene in pulmonary cells could occur during the pathological state.

Blood Proteins↗
PubMed1989

Effect of protein binding on testosterone extraction by human cirrhotic liver: evidence for a dissociation-limited uptake.

Testosterone (T) is a protein-bound substance, the hepatic extraction of which largely exceeds the free plasma fraction. In this study we attempted to determine if the dissociation of T from plasma proteins is the limiting factor for testosterone hepatic uptake in patients with cirrhosis. For this purpose we measured the hepatic uptake of T and the peripheral plasma concentrations of the different fractions of the hormone (total, free, albumin-bound, and sex hormone-binding globulin (SHBG)-bound) in 12 men with alcoholic cirrhosis. The hepatic extraction of T (mean = 42%) greatly exceeded the non-SHBG-bound fraction of T (free T plus albumin-bound T: mean = 13%). Thus, a substantial amount of SHBG-bound T must have entered the liver. A theoretical extraction ratio was calculated based upon the dissociation rate constants of T from albumin and SHBG and upon an estimate of sinusoidal transit time of plasma through the liver. The similarity between the measured and expected values indicates that the limiting step in hepatic uptake of T might be SHBG binding.

Adult↗
PubMed1989

Testosterone and its binding in hyperthyroid women before and under antithyroid drug therapy.

The serum concentrations of the different forms of circulating testosterone, total testosterone, free testosterone and non-sex-hormone binding globulin bound testosterone (albumin bound + free fractions) which is considered as the bioavailable hormone, were measured in 15 hyperthyroid women before and after anti-thyroid drug therapy and in 15 age-matched healthy women. Sex-hormone binding globulin and albumin were quantified. Total testosterone was significantly higher in hyperthyroid women before treatment, whereas free testosterone and non sex-hormone binding globulin bound testosterone were significantly decreased. After recovery, all the parameters returned to the normal range. In hyperthyroid patients, the variations in the different fractions of testosterone can be related to the rise of sex-hormone binding globulin. These variations could be explained by the displacement of the equilibrium defined by the binding equation.

Adult↗
PubMed1988

Determination of testosterone in serum not bound by sex-hormone-binding globulin: diagnostic value in hirsute women.

We compared the diagnostic value of information given by total testosterone (I), free testosterone (II), the free androgen index (III), and testosterone not bound by sex-hormone-binding globulin (SHBG) (IV) as measured by a new differential ammonium sulfate precipitation technique, each step of which is conducted at 37 degrees C. SHBG and albuminemia were also measured. To examine the clinical value of IV, we analyzed single blood samples from 15 hirsute women and 15 age-matched healthy control volunteers. Values for I, II, III, and IV testosterone were all significantly higher in the hirsute group (P less than 0.01), whereas SHBG was decreased (P less than 0.01) and albumin concentrations were similar for the two groups. Overlap between values for normal and for hirsute women was 33.3% for I, 13.3% for II, and 0% for III and IV. The presented data suggest that IV measured by ammonium sulfate precipitation is the preferred discriminator for detecting hyperandrogenism, because this assay is technically simpler and less expensive than the II assay for routine investigation. It closely reflects the pool of bioavailable testosterone; thus, its main use might be as a screening test for androgen excess in women.

Adult↗
PubMedDate not supplied

[RNA isolation and purification methods].

Recent advances in human, bacterial and viral genome projects and the development of quantitative real-time reverse transcription-polymerase chain reaction methods offer the possibility of analysing a large number of gene transcripts. These molecular developments represent an important advancein the field of genetics, cancer, virology, bacteriology and hematology. A limiting step remains the isolation of high quality mRNA purified from biological samples. This review describes the different methods used to isolate mRNA from biological samples and to verify RNA integrity and gives precise details about RNA storage conditions.

Blotting, Northern↗
PubMedDate not supplied

[RT-PCR in clinical diagnosis].

Application fields of RT-PCR (reverse transcription-polymerase chain reaction) in clinical diagnosis comprises the assessment of viral load for RNA viruses and the analysis of gene transcription products. RT-PCR is also helpful when large genes have to be sequenced. Developments of quantitative approaches using real-time PCR recently led to a major widening of RT-PCR applications in clinical diagnosis. However, RT reaction is delicate due to its lack of reproducibility and to RNA lability and frequent contamination by DNA. In some cases additional difficulties come from the need to obtain a specific amplification in the presence of homologous sequences which might be present in higher amounts than the sequence of interest. These caveats have to be taken into account, when designing the RT protocol, and when choosing PCR primers and internal and/or external references. This review is aimed at helping the experimental setup of a RT-PCR based assay according to the objectives.

Clinical Medicine↗