DIAGNOSIS OF ENDOCRINE DISEASE: Sex steroid action in adolescence: too much, too little; too early, too late.

ABSTRACT: This review aims to cover the subject of sex steroid action in adolescence. It will include situations with too little sex steroid action, as seen in for example, Turners syndrome and androgen insensitivity issues, too much sex steroid action as seen in adolescent PCOS, CAH and gynecomastia, too late sex steroid action as seen in constitutional delay of growth and puberty and too early sex steroid action as seen in precocious puberty. This review will cover the etiology, the signs and symptoms which the clinician should be attentive to, important differential diagnoses to know and be able to distinguish, long-term health and social consequences of these hormonal disorders and the course of action with regards to medical treatment in the pediatric endocrinological department and for the general practitioner. This review also covers situations with exogenous sex steroid application for therapeutic purposes in the adolescent and young adult. This includes gender-affirming therapy in the transgender child and hormone treatment of tall statured children. It gives some background information of the cause of treatment, the patient's motivation for medicating (or self-medicating), long-term consequences of exogenous sex steroid treatment and clinical outcome of this treatment.

Detection of SARS-CoV-2 antibodies using commercial assays and seroconversion patterns in hospitalized patients.

OBJECTIVES: SARS-CoV-2 antibody assays are needed for serological surveys and as a complement to molecular tests to confirm COVID-19. However, the kinetics of the humoral response against SARS-CoV-2 remains poorly described and relies on the performance of the different serological tests. METHODS: In this study, we evaluated the performance of six CE-marked point-of-care tests (POC) and three ELISA assays for the diagnosis of COVID-19 by exploring seroconversions in hospitalized patients who tested positive for SARS-CoV-2 RNA. RESULTS: Both the ELISA and POC tests were able to detect SARS-CoV-2 antibodies in at least half of the samples collected seven days or more after the onset of symptoms. After 15 days, the rate of detection rose to over 80% but without reaching 100%, irrespective of the test used. More than 90% of the samples collected after 15 days tested positive using the iSIA and Accu-Tell® POC tests and the ID.Vet IgG ELISA assay. Seroconversion was observed 5 to 12 days after the onset of symptoms. Three assays suffer from a specificity below 90% (EUROIMMUN IgG and IgA, UNscience, Zhuhai Livzon). CONCLUSIONS: The second week of COVID-19 seems to be the best period for assessing the sensitivity of commercial serological assays. To achieve an early diagnosis of COVID-19 based on antibody detection, a dual challenge must be met: the immunodiagnostic window period must be shortened and an optimal specificity must be conserved.

[Sinusal penetration of amoxicillin-clavulanic acid. Formulation 1 g./125 mg., twice daily versus formulation 500 mg./125 mg., three times daily]. / Pénétration sinusienne de l'amoxicilline-acide clavulanique. Formulation 1 g/125 mg, 2 fois/jour, versus formulation 500 mg/125 mg, 3 fois/jour.

INTRODUCTION: In order to meet the evolution of pneumococcus resistance to beta-lactam antibiotics, a new formulation of amoxicillin (AMX) and clavulanic acid (CA), with twice as much AMX (1 g/125 mg vs. 500 mg/125 mg) was developed for the treatment of acute pneumonia in patients at risk. This formulation can also be used in the treatment of acute maxillary sinusitis using a 1 g/125 mg regimen twice-daily. OBJECTIVES: Compare the sinusal penetration of AMX and CA (1 g/125 mg twice-daily vs. 500 mg/125 mg three times a day) when administered at both regimens to demonstrate equivalent pharmacokinetic and pharmacodynamic behaviour of the former when compared to the latter. METHODS: Concentrations of AMX and CA were measured in the anterior ethmoid, maxillary, posterior ethmoid sinus and in the middle nasa concha in 62 patients undergoing surgery for nasosinusal polyps. Patients randomised in two groups corresponding to 2 oral regimens, received either 1 g/125 mg twice a day or 500 mg/125 mg three times a day for 4 days. The last dose in both groups was administered 1 h 30, 3, 5 or 8 hrs prior to surgery. Serum samples were taken simultaneously to tissue samples. AMX and CA were measured by high performance liquid chromatography. Exogenous and above all endogenous blood contamination were taken into account with the hematocrit as well as blood and tissue haemoglobin concentrations. Comparisons of tissue concentrations were made for each sampling time, according to values obtained for a specific tissue with both doses on one hand, and on the other to values obtained with a specific dose in different tissues. The calculated pharmacodynamic parameters, which are considered to be predictive for bacteriological and clinical efficacy, result directly from tissue concentrations of AMX. tissue inhibitory quotients (IQtissue = Tissue concentration/MIC). time above MICs for serum and tissue concentrations (T > MIC). RESULTS: As regards AMX, whatever the dose, at 1 h 30 and at 3 hrs, tissue concentrations did not differ significantly whatever the tissue studied (from 1.1 to 2.5 micrograms/g). Conversely, at 5 and 8 hrs, they were greater than after the 1 g/125 mg regimen given twice-daily (0.06-0.7 vs. 0.7-1.8 micrograms/g). If we consider a given dose, the comparison between the various tissues showed identical concentrations in the four tissues studied at each sampling time, except in two cases with the dose of 500 mg/125 mg 3 times a day. T > MIC for serum and tissue showed higher values than those required for AMX/pneumococcus association (40-50%) with, nevertheless, greater tissue values for the 1 g/125 mg dose given twice-daily when MIC was of 1 microgram/ml (40-52% vs. 50-66%). The maximum tissue inhibitory quotients were also greater with the twice-daily 1 g/125 mg dose, when calculated with MIC 50 or 90 of S. Pneumoniae, H. influenzae, M. catarrhalis or S. pyogenes. As for CA, concentrations were equivalent for both doses at each sampling time and greater than those required in vitro during respectively 4 and 5 hours for beta-lactamases H. influenzae and M. catarrhalis. DISCUSSION-CONCLUSION: A least an equivalence between both dose regimens was observed, with occasionally a superiority of the twice-daily 1 g/125 mg dose, in terms of pharmacokinetics, tissue penetration and pharmacodynamics for both AMX and CA. This new regimen therefore appears more appropriate for the treatment of acute maxillary sinusitis in adults.

Assessing excess nurse work load generated by multiresistant nosocomial bacteria in intensive care.

OBJECTIVE: To compare three methods for assessing the excess nurse work load related to recommended procedures for managing nosocomial infections (NI) due to multiresistant bacteria (MRB): two activity scores, the Omega score and the Projet de Recherche en Nursing (PRN) system, and a specific evaluation based on functional analysis of nursing procedures. SETTING: 10 beds in a medical intensive care unit (MICU). PATIENTS: Patients admitted from November 15, 1995, to June 15, 1996, were included and divided in two groups based on presence of MRB colonization or infection (MRB+ and MRB-groups). METHODS: Data were collected regarding length of stay (LOS) in days; Omega score for the entire stay; PRN score for the entire stay and per day; and time required to perform correctly four nursing procedures related to MRB NI, as evaluated specifically by the nursing staff, using a detailed functional analysis document that described all elementary nursing tasks in chronological order and all material needed to carry out those tasks. RESULTS: The LOS and total Omega and PRN scores were higher in the MRB+ group than in the MRB- group: LOS, 23 +/- 20.6 versus 12 +/- 15.3 days, (P<.001); Omega score, 164 +/- 103.4 versus 123 +/- 93.7 points (P<.001); PRN score, 3,606 +/- 3,187 versus 1,854 +/- 2,356 points (P<.001), respectively. The daily PRN score was also higher in MRB+ group (PRN, 160 +/- 25 vs 146 +/- 34 points in the MRB- group; P<.028). Four nursing procedures made necessary by MRB acquisition were identified: isolation precautions, with two levels according to whether the risk of contamination was mild-moderate or high; bathing the patient with antiseptic solution; bedpan management; and microbiological screening. The functional analysis indicated that the time needed to carry out these four procedures correctly was 245 minutes per patient per day, as compared to 85 minutes according to the PRN system. CONCLUSIONS: Our data confirm that MRB NIs are responsible for an increase in nurse work load, as estimated by LOS, Omega, and PRN scores. However, the daily excess nurse work load related directly to recommended procedures for managing MRB NIs in MICUs is underestimated by these activity scores, as compared to a specific functional analysis of nursing tasks. This may be of importance in evaluating potential links between nurse work load and MRB NIs and in determining the number of nurse hours needed to comply with infection control recommendations.

Gastric penetration of amoxicillin in a human Helicobacter pylori-infected xenograft model.

The delivery of antibiotics into Helicobacter pylori-infected human stomachs is still poorly understood. Human embryonic gastric xenografts in nude mice have recently been proposed as a new model for the study of H. pylori infection. Using this model, we compared the penetration of amoxicillin, after intraperitoneal administration of a dose of 20 mg/kg of body weight, into the gastric mucosae of infected and uninfected xenografts. The concentrations of this drug in serum and superficial gastric mucosae were determined at 20 min and 1 and 3 h after injection. Ten mice with H. pylori-infected grafts (n = 5) or uninfected grafts (n = 5) were studied. Mucosal samples were obtained by cryomicrotomy. The concentrations in serum were similar to those obtained in the serum of humans after oral administration of 1 g of amoxicillin. The mean area under the tissue concentration-versus-time curve from 0 to 3 h obtained for mice with infected grafts was significantly higher than that obtained for the animals with uninfected grafts (P = 0.01). These results suggest that the penetration of amoxicillin into the superficial gastric mucosa may be substantially increased in the case of H. pylori infection. Thus, human xenografts in nude mice represent a new, well-standardized model for investigation of systemic delivery of drugs into H. pylori-infected gastric mucosa.

Analysis of recent antimicrobial agents in human biological fluids by high-performance liquid chromatography.

Our previous review on the liquid chromatographic (LC) analysis of anti-bacterial agents was published in 1990 in a special issue of the Journal of Chromatography. Eight years later, some new agents have been registered and numerous other are under clinical experiment. In spite of therapeutic problems encountered with certain bacterial pathogens, the development of novel drug candidates has slowed partially due to the need for identification of new bacterial targets and the cost of the research. The present overview updates the LC methods for the quantitations of recent antimicrobial agents (marketed and in clinical development) in human biological fluids. Consideration has been given to procedures permitting the determination of isomers and metabolites as well as methods regarding tissue extracts or liquid sampled from physiological sanctuaries. LC methods are available for the quantitation of almost all registered or investigated recent anti-infective drugs and some are applicable in routine practice. Nevertheless, few techniques have been validated for the determination in tissue extracts limiting the development of penetration studies.

Capillary electrophoresis for pharmacokinetic studies.

Different analytical techniques involving capillary electrophoresis for the determination of drugs and metabolites in biological fluids are described. Pharmacokinetic studies carried out using capillary electrophoresis are presented, as well as the in vitro metabolism investigations. The advantages and the limitations of capillary electrophoresis for pharmacokinetic studies are discussed.

Food and nutrient intake outside the home of 629 French people of fifteen years and over.

OBJECTIVE: This study was conducted to assess nutrient intake outside the home of 629 people representative of the French population. SUBJECTS: The study population consisted of 629 people aged 15 years and over. They were recruited in a randomized way with two levels (town and household). METHOD: Food intake outside the home was assessed by self-completed estimated record for 7 d. Individuals referred to photographs to estimate portions. Nutrient intake has been calculated for energy, protein, carbohydrate, fat and some minerals (calcium, phosphorus, magnesium, iron). RESULTS: Lunches and dinners eaten out are on average too rich in protein (20% of the energy), too high in fat (40-43% of the energy) and do not contain enough carbohydrate. The percentage of energy from sugars varies between 11% for lunch and 30% for breakfast. Mean intake of nutrients by beverages drunk outside the home decrease with the age of consumers. CONCLUSION: This study shows that foods and drinks consumed outside the home in France are on average too rich in fat and protein.

Pre-Main-Sequence Star Candidates in the Bar of the Large Magellanic Cloud

Candidate pre-main-sequence stars were observed in the bar of the Large Magellanic Cloud during the search for dark matter in the galactic halo. Seven blue stars of apparent visual magnitude 15 to 17 had irregular photometric variations and hydrogen emission lines in their optical spectra, which suggested that these stars are pre-main-sequence stars of about 10 solar masses. These stars are slightly more massive and definitely more luminous than are Herbig AeBe pre-main-sequence stars in our own galaxy. Continued observations of these very young stars from another galaxy, which are probably at the pre-hydrogen-burning stage, should provide important clues about early stages of star formation.

Photoaffinity labeling of peripheral-type benzodiazepine-binding sites.

The use of a novel photoaffinity label for the peripheral-type benzodiazepine-binding site is described. This compound, PK 14105, has high affinity (4 nM) and selectivity for cardiac benzodiazepine-binding sites. Under ultraviolet light, PK 14105 couples covalently to an 18,000-Da membrane protein which apparently corresponds to the (or a part of the) cardiac benzodiazepine-binding site. Since covalent attachment of PK 14105 totally precludes the binding of other ligands to this binding site, it is suggested that, during ultraviolet irradiation, this compound inserts covalently into the binding domain of the peripheral-type benzodiazepine-binding site.

Partial purification and pharmacology of peripheral-type benzodiazepine receptors.

This report describes the results obtained with a new photoaffinity ligand for the "peripheral-type" benzodiazepine binding site (PBS), using a digitonin solubilized preparation from rat heart or adrenals. The specific binding activity of the solubilized adrenal preparation is higher than 50 pmol/mg protein, with binding properties and pharmacological specificity identical to the membrane bound PBS. The apparent molecular weight of the solubilized PBS, determined by gel filtration is 215 KDa. The photoaffinity ligand (PK 14105) is a nitrophenyl derivative of PK 11195, which attaches covalently and specifically to all the PBS when cardiac membranes are irradiated with this compound under ultraviolet light. After photolabelling with [3H]PK 14105 and solubilization in SDS of heart or adrenal membranes, gel electrophoresis indicates the existence of a single protein band whose molecular weight (18 KDa) is unaltered by incubation with sulphydryl-reducing or protein cross-linking agents. This molecule seems to be a low molecular weight, acidic protein. Diethylpyrocarbonate decreases partially (60%) the binding of [3H]PK 11195 without affecting [3H] RO5-4864 binding, which implies a vital histidine residue in the binding domain of [3H]-PK 11195. Treatment with phospholipase A2 or mellitin, a stimulant of endogenous PLA2, led to a selective loss of [3H] RO5-4864 binding with no change in the binding of [3H]PK 11195. Such differences between a benzodiazepine ligand and an isoquinoline ligand suggest that these compounds may induce, on binding, different conformational changes in the PBS, which is compatible with the hypothesis that RO5-4864 and PK 11195 may be an agonist and an antagonist respectively at the PBS.

Stereoselective inhibition of the binding of [3H]PK 11195 to peripheral-type benzodiazepine binding sites by a quinolinepropanamide derivative.

The specific binding of [3H]PK 11195 to the peripheral-type benzodiazepine binding site is inhibited by the l-enantiomer of N,N-diethyl-alpha-methyl-2-phenyl-4-quinolinepropanamide ((-)Q1) but not by its d-enantiomer ((+)Q1). (-)Q1 inhibited [3H]PK 11195 binding to several rat tissues with an IC50 of less than 10 nM whereas (+)Q1 was at least 500 times less potent. This stereoselectivity was observed in all the tissues tested (brain, heart, kidney and adrenals). The same stereoselectivity was found for the displacement of the binding of [3H]PK 11195 in vivo, where (-)Q1 had an ID50 between 4-15 mg/kg and (+)Q1 was completely inactive at all doses tested (i.e. up to 40 mg/kg). Neither isomer had appreciable affinity for central-type benzodiazepine binding sites ([3H]diazepam) nor for voltage-sensitive calcium channels ([3H]PN 200210 and [3H]verapamil).

4-Amino-6-chloro-2-piperazinopyrimidines with selective affinity for alpha 2-adrenoceptors.

A series of 4-amino-6-chloro-2-piperazinopyrimidines were synthesized and evaluated for their ability to interact with alpha 1- and alpha 2-adrenoceptors in vitro in binding assays using [3H]WB-4101, [3H]clonidine, and [3H]idazoxan as radioligands. Some compounds were also tested as inhibitors of [3H]spiroperidol binding. Several members of this series showed high and selective affinity for alpha 2-adrenoceptors. The nature of the 4-amino substituent seems to be the most critical factor in determining the potency at these receptors.

PK 11195, an antagonist of peripheral type benzodiazepine receptors, modulates Bay K8644 sensitive but not beta- or H2-receptor sensitive voltage operated calcium channels in the guinea pig heart.

In a partially depolarized guinea pig papillary muscle preparation, BAY K8644 stimulated voltage-operated calcium channels, promoting slow action potentials; this effect was dose-dependent over a concentration range of 3 X 10(-7) M to 3 X 10(-6) M. Isoproterenol and histamine also induced slow action potentials by stimulating beta or H2 receptors, respectively. PK 11195, the antagonist of peripheral type benzodiazepine receptors, inhibited the effect of BAY K8644, but not those of histamine or isoproterenol. Moreover, PK 11195 "dose-dependently" antagonized the ability of RO5-4864 to inhibit the slow action potentials elicited by barium chloride. Thus, in the heart, PK 11195, an antagonist of peripheral type benzodiazepine receptors, can modulate voltage-operated calcium channels when they are activated directly, but not when they are activated by stimulation of neurotransmitter receptors.

Modulation of voltage-operated, but not receptor-operated, calcium channels in the rabbit aorta by PK 11195, an antagonist of peripheral-type benzodiazepine receptors.

We compared the effects of PK 11195, an antagonist of peripheral benzodiazepine receptors, on contractions of rabbit aorta by activation of either voltage-operated calcium channels (VOC) using BAY K 8644 (a calcium "agonist") and KCl or receptor-operated channels (ROC) using phenylephrine and B-HT 920, (alpha 1- and alpha 2-adrenoceptor agonist, respectively). In partially depolarized muscle strips, BAY K 8644 induced contractions that were noncompetitively inhibited by PK 11195 (pD'2 = 5.6 +/- 0.15). The effect of this calcium agonist was also antagonized by nitrendipine (competitively) and by yohimbine (noncompetitively), while prazosin was inactive. Contractions induced by KCl were inhibited by nitrendipine and, weakly, by PK 11195. Contractions induced by phenylephrine and B-HT 920 were inhibited competitively by prazosin and yohimbine and noncompetitively by nitrendipine, while PK 11195 was ineffective. It is concluded that PK 11195 behaves as an antagonist of VOC activated by BAY K 8644 and to a lesser extent by KCl depolarization but not of ROC coupled to alpha 1- and alpha 2-receptors.

PK 11195, an antagonist of peripheral benzodiazepine receptors, reduces ventricular arrhythmias during myocardial ischemia and reperfusion in the dog.

PK 11195, an antagonist of peripheral type benzodiazepine receptors, in doses from 5 to 25 mg/kg i.d. protected in a dose-dependent manner dogs against both early and delayed ventricular arrhythmias induced by 20 min ischemia and against ventricular fibrillation following reperfusion. Thus, peripheral-type benzodiazepine receptors might represent a novel target in the treatment of angina and cardiac ischemia.

Opposite effects of two ligands for peripheral type benzodiazepine binding sites, PK 11195 and RO5-4864, in a conflict situation in the rat.

The effects of two drugs acting at the peripheral type benzodiazepine binding sites, PK 11195 and RO5-4864, were examined in shock-induced suppression of drinking in rats. These two compounds have opposite effects : RO5-4864 (3.1-1205 mg/kg i.p.) enhanced whereas PK 11195 (25-50 mg/kg i.p.) decreased the punished responding, and PK 11195 (6.25 mg/kg, a dose which did not alter the punished responding) blocked the proconflict action of RO5-4864 (6.25 and 12.5 mg/kg). The effects of RO5-4864 and PK 11195 were not antagonized by RO15-1788, a selective antagonist of the central benzodiazepine site. In addition, PK 11195 (6.25 mg/kg) did not reverse the proconflict effect of two beta-carbolines : beta-CEE and FG 7142. AS picrotoxin did not change the punished responding, these data imply that the effects of RO5-4864 and PK 11195 on the one hand and those of chlordiazepoxide and beta-carbolines on the other hand are differentially mediated and suggest that the peripheral type benzodiazepine binding sites are involved in this conflict model.

Pharmacology of peripheral type benzodiazepine receptors in the heart.

RO5-4864 decreased in a dose-dependent manner the duration of intra cellular action potential and the contractility in the guinea pig papillary muscle. Diazepam was less active and clonazepam inactive. The effects of RO5-4864 were blocked by PK 11195 but not by RO15-1788. These results indicate that peripheral type benzodiazepine binding sites are pharmacological receptors. PK 11195 antagonized the increase and the decrease in the duration of intracellular action potential induced by BAY K-8644 and calcium channel blockers (nitrendipine, diltiazem, verapamil) respectively but not the increase induced by tetraethylammonium which blocks potassium channel. Moreover the decrease in contractility provoked by RO5-4864 was antagonized by 4 mM Ca2+. Thus peripheral type BZ receptors are coupled with Ca2+ channels in the heart.

Electrophysiological and pharmacological evidence that peripheral type benzodiazepine receptors are coupled to calcium channels in the heart.

PK 11195, an antagonist of the peripheral type benzodiazepine receptor, does not affect either the duration of the action potential or the tension of the guinea pig papillary muscle. However, it antagonized the effects of the calcium channel blockers, nitrendipine, verapamil, diltiazem, and of BAY K8644, a calcium channel agonist in this heart preparation. On the other hand, PK 11195 does not change the increase in the action potential duration provoked by the potassium channel blocker tetraethylammonium. RO5-4864, an agonist of the peripheral type benzodiazepine receptor, decreased the tension of the guinea pig papillary muscle. The effect was reversed by increasing extracellular Ca2+ concentrations up to 4 mM. These results suggest that in the heart the peripheral type benzodiazepine receptors are coupled to calcium channels.