Selective layer-free blood serum ionogram based on ion-specific interactions with a nanotransistor.

Despite being ubiquitous in the fields of chemistry and biology, the ion-specific effects of electrolytes pose major challenges for researchers. A lack of understanding about ion-specific surface interactions has hampered the development and application of materials for (bio-)chemical sensor applications. Here, we show that scaling a silicon nanotransistor sensor down to ~25 nm provides a unique opportunity to understand and exploit ion-specific surface interactions, yielding a surface that is highly sensitive to cations and inert to pH. The unprecedented sensitivity of these devices to Na+ and divalent ions can be attributed to an overscreening effect via molecular dynamics. The surface potential of multi-ion solutions is well described by the sum of the electrochemical potentials of each cation, enabling selective measurements of a target ion concentration without requiring a selective organic layer. We use these features to construct a blood serum ionogram for Na+, K+, Ca2+ and Mg2+, in an important step towards the development of a versatile, durable and mobile chemical or blood diagnostic tool.

[Diagnostic strategy in infertility due to hyperandrogenism. Development of a decision tree]. / Stratégie diagnostique au cours de l'infertilité avec hyperandrogénie. Elaboration d'un arbre décisionnel.

The detection of clinical hyperandrogenism in women presenting with infertility requires detailed hormonal investigations using the decisional plan suggested here. Initial studies including measurement of plasma androgen, gonadotrophic hormones and prolactin levels, may be sufficient to reveal an adrenal origin or pure ovarian origin. Non-tumor androgenic hypercorticism is seen classically in late-presenting enzyme deficits, but also in other situations: excessive adrenarche, hyperprolactinemia, obesity, chronic stress. The immediate Synacthene test can then eliminate diagnostic uncertainties if it leads to the discovery of appearances of 21- or 11-hydroxylase or 3 beta-ol dehydrogenase blocks. Intense virilisation in a woman with a testosterone level above 2 ng/ml (7 nM/l) should lead to suspicion of an androgen-secreting tumor of the ovary or adrenal. CT scan of the abdomen and true pelvis is essential here since it may reveal the presence of an adrenal or ovarian mass. If no morphological abnormality is shown by this investigation, an endocrine lesion of a small ovary should be strongly suspected, the demonstration of which requires isotope techniques and/or catheterisation of the ovarian veins. Two situations also exist which are responsible for severe hyperandrogenism but less alarming in terms of their course and significance: certain homozygous forms of 21-hydroxylase deficit diagnosed late and ovarian hyperthecosis. It may happen that these hormonal investigations do not suffice alone to determine the precise origin of hyperandrogenism and its cause. The dexamethasone adrenal suppression test is useful in the diagnosis of type II micropolycystic dystrophy, in order to define the essentially ovarian, adrenal or mixed origin of hyperandrogenism.

[Treatment of female infertility due to hyperandrogenism]. / Traitement des infertilités féminines par hyperandrogénie.

This study reviews the various types of treatment used in infertility due to hyperandrogenism, with the aim of answering the following three questions: How should these drugs be prescribed? What are their side-effects? What are the best diagnostic indications? Possibilities include ovulation inducers but also all types of treatment capable of improving the fertility of these women. The treatment of infertility due to adrenal hyperandrogenism is based upon glucocorticoids. This treatment must be continued for 3 months after conception, to attempt to avoid early spontaneous abortion. The first-line inducer in ovarian hyperandrogenism is clomiphene citrate. The good results obtained using the combination of dexamethasone and clomiphene citrate are explained by an adrenal participation in this type of hyperandrogenism. In case of failure, and in addition to classical menotrophins:--pre-treatment using LHRH agonists avoids the onset of premature luteinisation but does not prevent the possibility of multiple pregnancies;--use of purified FSH reduces, though not sufficiently, the risks of multifollicular maturation but does not greatly increase the overall pregnancy rate;--the "slow" protocol with purified FSH reduces the incidence of multifollicular maturation. Should this fail, prior treatment with an LHRH agonist and if not the pulsed administration of LHRH in non-obese women can be suggested. Surgical treatment provides useful results in severe forms of sterility due to polycystic ovaries syndrome, with new per-celioscopic techniques.

[Fertility disorders in 49 hyperandrogenic women desiring pregnancy. Treatment results aimed at obtaining a pregnancy in 40 hyperandrogenic infertile women and in 9 hyperandrogenic women desiring pregnancy]. / Troubles de la fertilité chez 49 femmes hyperandrogéniques désirant une grossesse. Résultats des traitements visant à obtenir une grossesse chez 40 femmes hyperandrogéniques infertiles et chez 9 femmes hyperandrogéniques désirant une grossesse.

The clinical and therapeutic aspects of fertility due to hyperandrogenism were studied in 49 women (40 presenting with sterility and 9 for another reason but seeking to become pregnant). Patients were divided into three main etiological groups on the basis of hormonal findings: ovarian (15 cases), adrenal (16 cases) and mixed (11 cases) hyperandrogenism. This study highlighted several points. 22% of infertile women had no cutaneous signs of hyperandrogenism and menstrual disturbances were missing in 46% of cases of adrenal hyperandrogenism. Primary infertility was seen more often in all types of hyperandrogenism (28 cases) than secondary infertility (12 cases). Secondary infertility was explained by a high early spontaneous abortion rate in hyperandrogenism (40%). This was much commoner in adrenal hyperandrogenism than in ovarian or mixed hyperandrogenism. Inducing treatment based upon a combination of dexamethasone and clomiphene citrate proved to be the most effective in these infertile women (86% pregnancy rate). The frequency of spontaneous abortions in infertility due to ovarian or mixed hyperandrogenism treated by clomiphene citrate alone can probably be explained by the persistence of hyperandrogenism.