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Biomedical subjects

F Dreyfuss

Publications and source records attributed to F Dreyfuss.

At least 19 recordsLinked to original sources
PubMed1984

Comparative immunoelectron microscopic localization of corticotropin-releasing factor (CRF-41) and oxytocin in the rat median eminence.

Comparative ultrastructural localization of corticotropin-releasing factor (CRF) and oxytocin was performed in the rat median eminence of Long Evans and Brattleboro rats. The peroxidase-antiperoxidase technique used on serial ultrathin sections revealed CRF and oxytocin neurosecretory granule colocalization in the same fibers of the internal layer running towards the posterior pituitary. It is probable that both these peptides coexist in the same granules. In the Brattleboro rats, while genetically lacking vasopressin, CRF was nevertheless shown to be present. In these rats, as was demonstrated in the Long Evans rats, CRF distribution paralleled that of oxytocin only in the internal zone of the median eminence.

Animals↗
PubMed1984

[The co-localization of neurohypophysis peptides and the corticotropin-releasing factor in the rat brain. Contribution of morphometric analyses].

Using adjacent serial brain sections, a morphometric method has been developed for analysing the coexistence of the neurophysial hormones, vasopressin (VP) and oxytocin (OT), with their specific neurophysins (N). A significative correlation was found between the immunoreactive areas stained with (1) anti-VP and anti-N-VP sera, and between the immunoreactive areas detected with anti-OT and anti-N-OT antibodies. Besides, the immunoreactive areas stained with (1) anti-VP and anti-OT antibodies, (2) anti-N-OT and anti-VP antibodies, (3) anti-N-OT and anti-N-VP antibodies or (4) anti-OT and anti-N-VP antibodies were totally independent. A different method projecting the microscope images on a reference grid with a camera lucida permitted to quantify the coexistence of an ovine corticotropin-releasing factor-related-peptide (41-CRF) with OT in the paraventricular neurons of the Brattloro rat brain. In these animals, the same method applied after total hypophysectomy demonstrated that the neurons synthezising simultaneously 41-CRF and OT projected their axons to the neurohypophysis; the same operation increased the relative number of neurons containing 41-CRF only; it can be supposed that they originated the infundibular terminals.

Animals↗
PubMed1980

[Contribution to the study of labeled neurohypophysial hormones. Preliminary data on the properties of the macromolecular compound: vasopressin-dextran (author's transl)].

The neuropeptide binding sites at the level of their target cells can be localized by several morphological methods. For one of the neurohypophysial hormones, vasopressin, not all labelling techniques can be applied: radioiodinated vasopressin has no biological activity; only 3Hvasopressin can be used. Immunocytochemical evidence for vasopressin receptors must be supported by complementary data in order to demonstrate the specificity of the binding. A new labelled ligand is prepared: vasopressin-dextran. In vivo, this macromolecular compound has antidiuretic properties equivalent to those of free vasopressin. In vitro, it gives a cross reaction with specific anti-vasopressin antibodies. For the same macromolecular compound, the ratio between the conjugated vasopressin estimated through R.I.A. and that assayed by biological method was 30.

Animals↗
PubMed1979

Ultrastructural and biochemical studies of the swelling of developing chick telencephalic slices.

An ultrastructural and biochemical study of the importance and localization of tissue swelling was performed on telencephalic slices of 1- and 30-day-old chicks incubated in an oxygenated or a non-oxygenated physiological medium. The swelling of slices is greater for 30-day-old chick material than for that from 1-day-old chicks. It also reaches higher values in the non-oxygenated than in the oxygenated medium. When the 30-day-old chick telencephalic slices are incubated in an oxygenated medium, swelling mainly affects astrocytes, and especially the astrocytic endfeet. When they are incubated in a non-oxygenated medium, the astrocytes and astrocytic endfeet are very swollen and in addition the swelling also affects the neurons and their organelles. Extracellular space is increased. When 1-day-old chick telencephalic slices are incubated in a non-oxygenated medium, the tissue structures are well preserved. Swelling predominantly affects astrocytes and astrocytic endfeet. Neurons are not affected and the extracellular space is reduced. However, when they are incubated in an oxygenated medium, tissue structures are greatly affected showing a high degree of disorganization. Extracellular space is greatly increased. This study thus indicates that the best incubation conditions are an oxygenated medium for 30-day-old chick telencephalic slices which are characterized by an aerobic metabolism, and a non-oxygenated medium for 1-day-old chick telencephalic slices which have a predominantly anaerobic metabolism.

Aerobiosis↗
PubMed1977

Magnet noncontact apexcardiography. A new technique for registering chest motion.

A new apexcardiographic recording system has been developed which is free of certain technical limitations. This noncontact magnetic transducer was tested alternately with a commonly used pneumatic piezoelectric transducer in a comparative study on ten normal subjects. The magnetic registration offered a more accurate timing and configuration of the ACG. Signal distortion, such as peaked waves and an early fall of the systolic wave, was eliminated. The magnetic transducer was capable of recording directional apex point tracings, as well as pulsations of a larger apical area. The new system proved to possess definite advantages and eliminated some of the inconveniences inherent in the pneumatically coupled system.

Humans↗
PubMed1977

Study of gastric emptying using a ferromagnetic tracer.

A new ferromagnetic method for the measurement of gastric emptying is described. An inert tracer, magnesium ferrite, is added to a test meal. Its amount in the stomach is then measured at regular intervals by an external transducer using its ferromagnetic properties. The method is noninvasive and devoid of radiation exposure. The magnetic fields used are harmless. The feasibility, reliability, and reproducibility of the method are described. Gastric emptying was studied in 61 subjects. The shape of the gastric emptying curve conformed best to an exponential function. The mean half-time of gastric emptying was 49 +/- 17.4 min. In this limited series age and sex did not affect gastric emptying.

Adolescent↗
PubMed1975

Polyamine excretion in the urine of cancer patients.

In the human body, the production of three polyamines--putrescine, spermidine and spermine--is largely associated with tissue growth, while that of a fourth--cadaverine--seems to be the result of bacterial action. In 37 (88%) of 42 cancer patients and in 24 (44%) of 54 patients with various nonmalignant diseases, increased amounts of polyamines were found in the urine. In the nonmalignant group, which served as a control group, the increased polyamine excretion was especially evident in patients with infections. There were, however, differences in the excretion patterns of the cancer and control groups: combinations of elevated levels of putrescine, spermidine and spermine were seen exclusively in the cancer patients; spermine was not found in the urine of women in the control group. The determination of urinary polyamines appears to hold promise as an aid in the diagnosis of malignant disease and in following up the results of therapy.

Adult↗