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Biomedical subjects

A Reuter

Publications and source records attributed to A Reuter.

14 recordsLinked to original sources

Enantiomeric purity of naproxen by liquid chromatographic analysis of its diastereomeric octyl esters.

A sensitive and specific analytical method was developed to determine the enantiomeric purity of naproxen. A simple derivatization of naproxen with (S)-(+)-2-octanol proceeded quantitatively and gave a mixture of diastereomeric esters displaying baseline separation on liquid chromatography. The ratio of these esters was the same as the ratio of enantiomers present in naproxen samples assayed. Reproducibility of the method was excellent.

Chromatography, Liquid

[Anti-ulcer agent pirenzepine (LS 519)--a tricyclic compound with particular physico-chemical properties (author's transl)].

Compound 5,11-dihydro-11-[(4-methyl-1-piperazinyl)acetyl]-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one dihydrochloride (pirenzepine, L-S 519) represents a new type of drug in ulcer therapy. It has been selected for broad clinical investigations because of its outstanding pharmacological profile. Pirenzepine is devoid of any central activity despite certain structural similarities in relation to psychotropic tricyclic compounds. The extraordinary pharmacokinetic and pharmacodynamic behaviour of this compound can be easily derived from its inherent physicochemical properties: The inability to pass the blood-brain barrier as well as its inability to activate the unspecific and specific psychotropic receptors is due to thermodynamic factors.

Anti-Ulcer Agents

Simultaneous assays of cancer-associated antigens in various neoplastic disorders.

Five tumor markers were measured simultaneously in serum by radioimmunoassay: carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), human chorionic gonadotrophin (HGC), the beta subunit of HCG, and Kappa casein. In a population of 935 normal subjects these antigens were undetectable or found within precise limits. In patients with tumors of various origins the rate of pathologically elevated levels was 72% at the beginning of the clinical course (194 cases). This high rate was primarily due to the simultaneous measurement of CEA, betaHCG, HCG, and casein. AFP was of little importance. The simultaneous measurement of these tumor markers may be one biochemical element of diagnosis of carcinoma, although this criterion is neither absolute nor specific, as 14.7% of patients with non-neoplastic disorders (234 cases) were positive for one antigen. In the presence of metastases (112 cases) the rate of pathologic levels of at least one antigen was increased: 86% due to CEA and casein assay at the same time as their absolute levels were increased. Surgical removal reduces the rate of positivity of these antigens to 37%. As was shown in patients with breast cancer, the rate was 10% when the tumor had been removed at Stage N- and 54% when it was removed at Stage N+. Thus, the persistence of pathologic levels could be correlated with the capacity for recurrence or metastases. Finally chemotherapy, radiotherapy, or both, do not decrease the rate of positivity of the tumor markers.

Adult

Prolactin levels during the menstrual cycle.

The levels of prolactin, FSH, LH, oestradiol and progesterone were measured daily during fourteen ovulatory cycles. The behaviour of FSH, LH, oestradiol and progesterone was classical. Non-systematic changes occurred in prolactin levels during the course of the menstrual cycle with the highest level being either during the ovulatory period or during the luteal phase. However, the mean level of prolactin was significantly higher during the ovulatory and luteal phases than during the follicular phase. A direct relationship between oestradiol and prolactin levels was noted, although there was no correlation between prolactin on the one hand and FSH, LH and progesterone on the other.

Adult

[Radioimmunoassay of thyroid stimulating hormone by sequential saturation].

The practice of sequential incubation in radio-immunoassay of TSH improves the sensitivity and precision without affecting the specificity compared with the method using simultaneous incubation of the constituents of the radio-immunological reaction. The determination of basic levels of TSH is more sensitive and more precise.

Cross Reactions

Peripheral blood T and B lymphocytes in men in different age groups.

Peripheral blood T and B lymphocytes were determined in normal humans at different ages. Spontaneous rosette formation with sheep red blood cells (SRBC) was used as a marker for T cells. B cells were detected by immunofluorescent staining of membrane-bound immunoglobulins. Blood samples from old individuals contained significantly lower T lymphocyte numbers than those from children. This diminution of circulating T cells caused a reduction of the total lymphocyte count in the elderly persons. No significant differences were between the T cell values of young and old adults. Whereas the percentages of B cells indicated an increase of this lymphocyte population in old humans, the absolute numbers of B lymphocytes remained almost unchanged during aging.

Adult

[Dosage of prolactin in normal and pathological subjects (author's transl)].

Homologous radioimmunoassay of human prolactin was performed and used to investigate the secretion of this pituitary hormone under normal and pathological conditions. The following data were developed in this paper: --During the menstrual cycle, prolactin levels are more elevated during ovulatory and luteal phases than during follicular phase; --During pregnancy, prolactin levels progressively increase to reach their maximum at the end of gestation; --During lactation, prolactin levels increase for the two days following delivery, then progressively decrease; --Bromocryptine oral administration drastically reduces prolactin levels within the 24 hours as it inhibits the prolactin release normally induced by suckling. Assays of prolactin is useful to define the role of this hormone in the genesis of the galactorrhea. Bromocryptine as L Dopa reduce the hyperprolactinemia either functional or tumoral in origin. TRH provokes prolactin release which is more pronounced in females than in males. Pituitary prolactin reserve may be appreciated in several pathological conditions. It appears to be of first interest to assess the residual function of the pituitary gland after surgical removal of adenoma. Depuis 1971, la prolactine humaine peut être dosée dans les milieux biologiques par méthode radio-immunologique (G. BRYANT et coll., 1971; M. L'HERMITTE et coll., 1972; H. FRIESEN et coll., 1972; SINHA et coll., 1973). En 1974 nous avons proposé une méthode de dosage radio-immunologique homologue (A. REUTER et coll., 1976). Grâce à celle-ci nous avons exploré la sécrétion de cette hormone hypophysaire dans certaines conditions normales et pathologiques.

Amenorrhea