The presence of thymulin (formerly called Facteur Thymique Sérique, FTS) in cultured human thymic epithelial cells was studied using a monoclonal anti-thymulin antibody in an immunofluorescence technique. The percentage of thymulin-containing cells increases gradually as a function of time, from 10% at day 4 to 90% at day 14. Furthermore, this increase can be prevented by the addition of thymulin in the culture medium. These data suggest a feedback control of thymulin secretion by thymic epithelial cells.
A monoclonal anti-MDP antibody was found to bind to "Slow Wave Sleep" factor. This result confirms that this factor is a muramyl peptide and furthermore shows that it contains a structure characteristic of the synthetic adjuvant and of the bacterial cell wall, i.e. an acetylated muramic acid bound to L-alanine. This antibody was also shown to specifically inhibit a biological activity of a purified human monokine which induces fever. Because of these results and other recent observations we propose that a bacterial structure is present in certain mammalian mediators.
The genetic code can be considered as degenerated from a minimal cyclic code, whose maximal chain is given. We study the relation of this code with the cyclic code corresponding to the 64 triplets. Finally we compare the minimal code to that obtained from a binary cyclic code.
RU-486 is a steroid which possesses a great affinity for the progesterone receptor, does not have a progesterone activity, but is indeed a strong antagonist of progesterone effects in animals. Oral administration induces the interruption of the luteal phase of the menstrual cycle and that of early pregnancy in women. Its mode of administration and its properties enable us to envisage a new methodology for menstrual cycle regulation and human birth control.
A female Rabbit immunized against bovine anti-Müllerian hormone (AMH) was mated and gave birth to 3 litters, containing a total of 13 males. Ten of these presented with Müllerian derivatives, of variable development. Testicular position and structure, Wolffian development and virilization of the urogenital sinus were apparently normal in males with persistent Müllerian ducts.
Metabolic clearance rate (MCR) of cortisol was measured in the adult male sand rat (Psammomys obesus) trapped live throughout the year in the region of Béni-Abbès in the Algerian Sahara Desert. Cortisol MCR exhibited marked annual variations which paralleled those of plasma concentrations of cortisol: it was highest in autumn, decreased in winter, rose again in early March, and was minimal in April and June. These data, taken together with previous results, suggest that the production rate of cortisol in the sand rat is lower in early summer than in autumn.
The hybridization between Schistosomes (S. mansoni) with an early and a late shedding pattern of cercariae lead to heterozygotous cercariae whose shedding pattern is characterized by two peaks (early and late). These results demonstrate the genetic support of the shedding rhythm of cercariae and suggest the participation of the daughter sporocyst in the chronobiological phenomenon of cercarial shedding.
In an enzyme complex where active subunits are aggregated in functional groups undergoing steric interactions, the Hill coefficient can reflect the ratio of the partial reaction order of the substrate upon the enzyme one, according to the mass action law. Honeybee haemolymph alpha-glucosidases kinetics support this theory in negative and positive cooperativity cases.
T lymphocytes and macrophages, isolated and purified from broncho-alveolar lavages performed in normal controls and in patients with various alveolar structure diseases were identified using monoclonal antibodies against different membrane markers. For T lymphocyte subsets, our results are consistent with previous observations showing a large number of lung helper T cells in patients with sarcoidosis with high-intensity alveolitis. For macrophage subsets, we pointed out, for all cases, a weak expression of monocyte markers.
The adenylate cyclase activity of Rat brain synaptosomal membranes is strongly activated by forskolin. This study demonstrates: 1. That GTP or its analogs, when added to forskolin, decrease the enzyme stimulation by a factor of 40 to 60%; 2. That Pertussis toxin (TP), in the presence of NAD, ADP-ribosylates a single membrane protein of 40,000 dalton apparent molecular weight in a strictly concomitant manner. This Lubrol-soluble protein has a sedimentation coefficient of 3.6 and a Stokes radius of 6 nm. An immune serum against TP blocks the NAD-glycohydrolase activity of the toxin.
A noticeable increase has been observed in the production of the C 3 component of the complement by Rat liver epithelial cells cultured in vitro in the presence of small quantities of supernatant of human blood mononuclear cells cultured for 72 hrs. with phytohemagglutinin. The physicochemical properties suggest that the stimulating factor(s) is(are) protein(s).
The biological activity of a synthetic fragment of choleric toxin. gamma Chain A subunit, was studied in vivo. This pentadecapeptide (10-24) was synthesized by solid phase method and finally purified by HPLC. Associated with the B subunit, the peptide inhibits the tissue water loss induced by commercial choleric toxin.
(Met5) enkephalin released from slices of Rat globus pallidus by 30 mM or 50 mM K+ is hydrolysed to the extent of 85% before reaching the incubation medium. When thiorphan and bestatin, two peptidase inhibitors, are added, this inactivation process is completely prevented but the peptide release from tissues is significantly diminished. The latter effect being reversed in the presence of an opioid antagonist, naloxone, in moderate concentration, the existence of an auto-inhibition process regulating enkephalin release is suggested.
In vitro measurements of spermatozoa migration in different media showed a 75% increase in the number of spermatozoa migrating into preovulatory human follicular fluid versus Menezo's fluid. However after 4 h storage in either medium, total and progressive motility of the spermatozoa was lower in follicular fluid than in Menezo's fluid. A positive correlation was evident between the spermatozoa migration in follicular fluid and the concentration or motility of spermatozoa in fresh sperm.
Hybridomas secreting monoclonal antibodies directed against Rat gastric L-histidine decarboxylase (H.D.) have been obtained from a partially purified preparation and screened by immunoprecipitation of the enzyme activity. They cross react with Rat brain H.D., indicating at least that these two enzymes share common antigenic determinants.
L-929 cells secrete a neurotrophic factor which is immunologically related to the beta NGF present in the male Mouse submaxillary gland. In order to determine whether L-929 cells also synthesize the alpha and gamma subunits which are associated with the beta NGF in the gland, immunoprecipitations were performed with appropriate antisera. Our results indicate the absence of alpha and gamma subunits in the extracellular medium or in the cell extracts and suggest that the synthesis and secretion of the beta NGF by the L cells does not require these two proteins.
Ultrastructural immunocytochemistry with anti-insulin antiserum allowed the detection of insulin antigenic sites localized at the inner aspect of the cisternae of the Golgi apparatus in pancreatic B-cells. By contrast, in secretory granules released from the Golgi apparatus, insulin antigenic sites were localized over the granule content but not on the membrane. The demonstration of insulin antigenic sites at the level of the Golgi membranes is compatible with the presence of specific insulin receptors and/or charge interactions between the insulin and the membrane. Binding at this level could in turn be involved in the sorting out of insulin polypeptides destined to be concentrated in secretory granules.
We compare the acute toxicity of a dose of gentamicin or dibekacin in Mice at different times of the day. The female Mice are housed with food and water ad libitum for one and half week, ten or fifteen per cage in a light controlled room (lights on from 8 to 20 hrs). Each animal was given gentamycin (250, 275, 300 or 325 mg/kg) intramuscular and dibekacin (320, 355, 390, 425 or 460 mg/kg) at one of four times: 8, 14, 20 and 2 hrs). After injection, the animals are kept in their cages and observed for 10 days. We show that the circadian biosusceptibility rhythm in dibekacin toxicity is similar to that of gentamycin with significant differences in the mortality at the four hours. There is an evident parallelism between the curves for gentamycin and dibekacin but the differences in the percentage of mortality rate are more important for gentamycin than for dibekacin.
The C5b-9 neoantigen of the terminal complex of human complement was localized on cell remnants in connective matrices of normal kidney using immunohistochemical techniques. These observations suggest that the complement system plays a role in the shedding process of plasma membranes from aging cells.
