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D Royere

Publications and source records attributed to D Royere.

26 records · Page 2Linked to original sources
PubMed1988

Freezing and thawing alter chromatin stability of ejaculated human spermatozoa: fluorescence acridine orange staining and Feulgen-DNA cytophotometric studies.

Cryopreservation and freezing-thawing effects on the fertilizing ability of human spermatozoa commonly are evaluated by post-thaw motility. Various studies have depicted the ultrastructural changes caused by freezing-thawing, yet the chromatin alterations have been studied very limitedly. Our aim was to determine the extent to which freezing-thawing alters the chromatin of human spermatozoa, using two analytical methods: acridine orange staining and Feulgen-DNA cytophotometric studies. Both methods revealed a dramatic effect of freezing-thawing on sperm chromatin: the native DNA content decreased as did the Feulgen-DNA content, and sperm surface area was reduced. These results indicate an effect on DNA, diminished accessibility for Feulgen, and a decrease in nuclear surface area and prompt us to hypothesize a relationship between an "overcondensation" state for sperm chromatin after freezing-thawing and a lower conception rate for human semen after cryostorage.

Acridine Orange↗
PubMed1988

[Insulin-resistant diabetes and polycystic ovary].

The observation of one patient with insulin resistance (114 unités of soluble insulin in 3 injections per day + 54 units of medium acting insulin at 8 pm) associated with a polycystic ovarian disease prompted us to discuss the relationship between hyperandrogenism, acanthosis nigricans and endogenous hyperinsulinism. An in vitro study of the insulin binding to patient's erythrocytes allowed to diagnose the rare Type A insulin-resistance syndrome proposed by Kahn.

Adolescent↗
PubMed1987

[Study of the plethysmographic amplification factor during vasodilator treatment. Healthy subject versus primary Raynaud phenomenon].

Digital arterial circulation before and after administration of a vasodilator orally was explored by mercury gauge pulsed plethysmography and photoplethysmography in 12 patients with primary Raynaud's phenomenon and results compared with those of 10 healthy volunteers. The amplification factor F, ratio of amplitude in reactive hyperemia over amplitude at rest was determined in the index before and after 8 mg daily of dihydroergokryptine over 4 weeks. Before treatment, for each of the two plethysmographic technics, a significant increase in mean factor F values was noted in the patients with Raynaud's phenomenon when compared with healthy controls. This is due to a decline in digital arterial flow at rest. Using the mercury gauge plethysmograph, a significant reduction in factor F was observed after vasodilator treatment corresponding to an increase in digital flow at rest without increase in flow during hyperemia. Using photoplethysmography, no significant variation in factor F was noted after treatment. Mercury gauge plethysmography, which measures global digital blood flow appears to be a more sensitive method than photoplethysmography, which measures dermal and hypodermal blood flow, for follow-up of effects of vasodilator treatment on Raynaud's phenomenon.

Adult↗
PubMedDate not supplied

Cryopreservation of spermatozoa: a 1996 review.

Both the ability to freeze human spermatozoa and the possibility of pregnancy following intrauterine insemination have existed for >40 years. There have been a number of improvements during that time concerning the methods of freezing and thawing human spermatozoa. Initially, the use of the cryoprotective properties of glycerol allowed a major improvement; subsequently, changes were mainly empirical. It was a long time before specific cryobiological studies were undertaken. However, the necessity for these became apparent with the partial recovery or sometimes loss of motility after freezing either subfertile semen before chemotherapy or radiotherapy, or spermatozoa collected from non-physiological situations (epididymal or testicular spermatozoa). The main trends in improvement have defined end-points other than the percentage of motility recovery or the assessment of ultrastructural damage. More sensitive criteria of the objective assessment of motility, energy status, damage to the plasma membrane or to subcellular elements, chromatin stability and chromosomal damage have been proposed as complementary end-points to better assess sperm cryopreservation. A different approach was related to the biochemical environment and physical conditions imposed on spermatozoa during the freezing and thawing process. Biochemical changes were assessed following different combinations of various extenders which attempted either to better preserve some parameter or to avoid the tendency towards drastic increase in osmotic pressure. Analysis of physical conditions was linked to the rate of cooling, freezing and warming, and was based on cryobiological studies. Finally, even though such improvements are not negligible, many questions remain unanswered. The extensive use of frozen spermatozoa during assisted reproductive techniques, together with the development of assisted fertilization using surgically collected spermatozoa, creates the need for additional studies to improve the cryopreservation of human spermatozoa.

Cryopreservation↗
PubMedDate not supplied

Follow-up studies of children born after frozen sperm donation.

The need to assess the health of children born after assisted reproductive technologies (ART) using frozen donor spermatozoa has been a major concern for the last decade. Most available published studies are confusing (since they are retrospective) and refer to small numbers of cases or involve a bias. Two prospective and large population-based studies have been published, one in France and the other in Australia. The general characteristics of children born after ART using frozen spermatozoa was unchanged in comparison with the general population (weight, prematurity, stillbirths, sex ratio). However, the rate of multiple pregnancy was increased, first in artificial insemination with donor semen (AID), where the use of hormonal treatment may be too heavily prescribed, and second in IVF with donor semen (IVF/D) where both the ovulation induction treatments and embryo transfer policy increase the rate of multiple pregnancies. As far as birth defects or chromosomal abnormalities are concerned, no difference has been observed from the general population. Finally, the use of frozen spermatozoa does not seem to affect the health of children conceived by AID or IVF/D. The psychosocial development of such infants is not as well known because of the confidentiality in many countries concerning sperm donation. However, the available information on the psychosocial development of these children up to the age of 8-10 years appears to be reassuring. Larger and longer studies are needed to answer such questions, particularly with regard to adulthood.

Birth Weight↗
PubMedDate not supplied

Analysis of the lipid content and the motility of human sperm after follicular fluid treatment.

The effect of human follicular fluid (hFF) on the cholesterol and phospholipid content and the movement characteristics of human spermatozoa were studied. Semen was selected by a discontinuous Percoll gradient and incubated during in vitro capacitating conditions with B2 medium supplemented with hFF 20%. Percoll pelleted spermatozoa were incubated in either B2 (B2-Percoll) or B2 supplemented with hFF (hFF-Percoll). In hFF-Percoll, we observed a time-dependent (24 h) decrease in both the cholesterol and phospholipid contents (cholesterol: 10.1 vs. 8.7 nmol 10(-7) spermatozoa; phospholipids: 17.5 vs. 15.7 nmol 10(-7) spermatozoa, P < 0.05). This decrease in cholesterol and phospholipids in human spermatozoa was concomitant with a high straight line velocity, a high progressive motility percentage and an increased value of lateral head displacement without any significant alteration of the spermatozoal membrane. No modification of the cholesterol: phospholipid ratio after 2 and 24 h of incubation in either B2-Percoll (0.61, 0.54) in hFF-Percoll (0.59, 0.63) was observed when compared with original control semen. It is suggested that the decrease in cholesterol and phospholipids in hFF-Percoll may be taken into account for the changes of membrane modification as part of the capacitation process.

Cholesterol↗
PubMedDate not supplied

[Basedow's neuropathy].

A case report of grave's neuropathy. The symptoms appeared in a treated patient when there was a biologic hypothyroidy. A total remission was observed after corticotherapy. Nevertheless, a recurrence of disease happened for reduced doses, so an orbital radiotherapy was requisited. Student of differents treatments for dysthyroid neuropathy.

Adult↗