Effects of prenatal dexamethasone exposure on adult C57BL/6J mouse metabolism and oxidative stress

Prenatal glucocorticoid exposure has been shown to alter hypothalamic-pituitary-adrenal axis function resulting in altered fetal development that can persist through adulthood. Fetal exposure to excess dexamethasone, a synthetic glucocorticoid, has been shown to alter adult behaviour and metabolism. This study investigated the effects prenatal dexamethasone exposure had on adult offspring cardiac and liver metabolism and oxidative stress. Pregnant C57BL/6 mice received a dose of 0.4 mg/kg dexamethasone on gestational days 15-17. Once pups were approximately 7 months old, glucose uptake was determined using positron emission tomography and insulin resistance (IR) was determined by homeostatic model assessment (HOMA) IR calculation. Oxidative stress was assessed by measuring 4-hydroxynonenal protein adduct formation and total reactive oxygen species. Female dexamethasone group had significantly increased glucose uptake when insulin stimulated compared to vehicle-treated mice. HOMA IR revealed no evidence of IR in either male or female offspring. There was also no change in oxidative stress markers in either cardiac or liver tissues of male or female offspring. These data suggest that prenatal dexamethasone exposure in male mice does not alter oxidative stress or metabolism. However, prenatal dexamethasone exposure increased glucocorticoids, cardiac glucose uptake, and pAkt signaling in female heart tissues in adult mice, suggesting there are sex differences in prenatal dexamethasone exposure.

The usefulness of the leuprolide stimulation test as a diagnostic method of idiopathic central precocious puberty in girls

Central precocious puberty (CPP) diagnosis is based on clinical evaluation, but hormonal evaluation is crucial. The aim of the study was to evaluate the usefulness of the leuprolide stimulation test for diagnosis of idiopathic CPP. Sixty-one girls, aged 5-8 years, were evaluated retrospectively for premature breast development. According to clinical evolution, 28 had progressive puberty and 33 nonprogressive puberty. All underwent a leuprolide stimulation test. Cutoff points, sensitivity, and specificity for gonadotropins and estradiol were determined by receiver operating characteristic (ROC) curves. Cutoff points for CPP were: baseline LH: > 0.1 mUI/l, FSH: > 2.3 mUI/l, LH/FSH ratio: > 0.23, estradiol: > 12 pg/ml; and stimulated LH: > 5.5 mUI/l, LH/FSH ratio: > 0.24, estradiol: > 79.67 pg/ml. The best diagnostic efficiency for progressive puberty were stimulated LH/FSH ratio (sensitivity: 100%, specificity 94%) followed by stimulated LH (sensitivity: 93%, specificity: 100%). Stimulated LH/FSH ratio and LH resulted in the most useful parameters for the diagnosis of CPP. Stimulated estradiol did not add more information.

Height gain at adult-height age in 184 short patients treated with growth hormone from prepubertal age to near adult-height age is not related to GH secretory status at GH therapy onset

BACKGROUND

GH release after stimuli classifies short children as severe idiopathic isolated GH deficiency (IIGHD), mild IIGHD, dissociated GH release (DGHR) and normal GH release (NGHR) and anthropometric birth data as adequate for gestational age (AGA) or small for gestational age (SGA). GH release after stimuli classifies AGA patients as IIGHD or as idiopathic short stature (ISS).

AIM

To compare height gain induced by GH therapy (31.8 ± 3.5 µg/kg/day, 7.7 ± 1.6 years) started at prepubertal age and stopped at near adult-height age.

METHODS

A retrospective longitudinal multicenter study including 184 short patients classified as severe IIGHD n = 25, mild IIGHD n = 75, DGHR n = 55 and NGHR n = 29; or as IIGHD n = 78, ISS n = 57 and SGA n = 49. Height gain was evaluated throughout GH therapy and at adult-height age.

RESULTS

Height-SDS gain at adult-height age was similar among severe IIGHD (1.8 ± 0.8 SDS), mild IIGHD (1.6 ± 0.6 SDS), DGHR (1.7 ± 0.7 SDS) and NGHR (1.6 ± 0.7 SDS), or among IIGHD (1.7 ± 0.7 SDS), ISS (1.7 ± 0.6 SDS) and SGA (1.6 ± 0.8 SD).

CONCLUSION

GH-release stimuli are of little help for deciding on GH therapy in the clinical management of prepubertal children with IIGHD, ISS or SGA.

Growth hormone secretory status evaluated by growth hormone peak after two pharmacological growth hormone release stimuli did not significantly influence the two-year catch-up growth induced by growth hormone therapy in 318 prepubertal short children with idiopathic growth retardation

BACKGROUND/AIMS

In prepubertal short children with idiopathic growth retardation, growth hormone (GH) peak after GH release stimuli classifies patients as growth hormone- deficient (GHD) or non-GHD. This study compared a 2-year growth response to GH therapy in 318 prepubertal short children.

METHODS

Patients were classified as: severe GHD (GH peaks <5 ng/ml after 2 stimuli; n = 54), mild GHD (GH peaks <10 ng/ml, but one or two between 5 and 10 ng/ml; n = 140), dissociated GH release (GH peak ≥ 10 ng/ml after 1 stimulus and <10 ng/ml after the other; n = 89), and normal GH release (GH peaks ≥ 10 ng/ml after 2 stimuli; n = 35).

RESULTS

Two-year height gain did not differ statistically among the 4 groups: 1.39 ± 0.51 SD, 16.4 ± 2.3 cm; 1.23 ± 0.56 SD, 15.8 ± 2.1 cm; 1.18 ± 0.53 SD, 15.3 ± 2.0 cm, and 1.14 ± 0.53 SD, 15.4 ± 2.0 cm, respectively, as was also the case for bone age gain: 2.5 ± 0.6, 2.4 ± 0.7, 2.6 ± 0.7 and 2.3 ± 0.5 years, respectively.

CONCLUSIONS

Our results suggest that GH release stimuli are of little help for deciding on GH therapy in the clinical management of prepubertal short children with idiopathic growth retardation, while well-defined anthropometric and biochemical criteria may be useful.

[Usefulness of transrectal ultrasonography in the diagnosis of anomalies of intersexual conditions]

INTRODUCTION

Between the external genital exploration and the internal genital direct vision, through laparoscopia, there is a black point which is the pelvic floor; we have to know whether there is a vagina or not, what it is like and where it arrives at. The reason for this research is to present our experience with the transrectal ecography, which allows us a very good exploration of the pelvic floor.

MATERIAL AND METHODS

We present 6 patients, the youngest is 16 months old and the oldest is 19 years old, who have a diagnostic of 3 congenital adrenal hyperplasia (HSC), 2 gonadal dysgenesis and 1 vaginal agenesis (S. Rokitanski). Under sedation, we carried out a transrectal ecography with Aloka SSD650 ecograph and 7.5 MHz vaginal scanner. Ultrasone.

RESULTS

In case of HSC (16 months old), the transrectal ecography showed the vaginal arrival at the urethra and we were able to measure the distance from the external sphincter. In the other two HSC, which had been surgically corrected, the transrectal ecography clearly showed the vagina (length and calibre). In the two gonadal dysgenesis (two 11-and-19-year-old sisters, the first of whom had undergone vulvo-vaginoplasty, we appreciated the length of the vagina and, in the case of the sister with a relatively normal vagina, we confirmed the presence of the vagina connected to the uterus. In the vaginal agenesis, in which a neovagina with amnion membrane had been carried out, which, in its turn, ended in a situation of hematometra due to a stenosis, the transrectal ecography was really helpful to obtain vaginal dilatations.

CONCLUSIONS

Ecography is an easily available technique and provides both through and detailed information of the genital structures going through the pelvic floor, a zone which is otherwise difficult to explore. It was done under sedation for the patient's age and idiosyncrasy. The experience has just started but we are sure that in the future it will replace the genitograma.

[Low sensitivity of IGF-I, IGFBP-3 and urinary GH in the diagnosis of growth hormone insufficiency in slowly-growing short-statured boys. Grupo Español de Estudio de la Talla Baja]

BACKGROUND

The usefulness of IGF-I, IGFBP-3, and the urinary GH excretion in the diagnostic evaluation of growth retardation in boys with short stature was studied.

SUBJECTS AND METHOD

Serum samples from two GH-stimulation tests and two 24-h urine samples were sent to a Central Laboratory to measure serum and urinary GH, serum IGF-I, IGFBP-3 and GHBP, both in absolute and standardized values (Z-score). Short children were classified as growth hormone deficient (GHD) (n = 25), and idiopathic short statured (ISS) (n = 54), on the basis of the peak stimulated GH concentration of < 7.5 microg/l or > or = 7.5 microg/l respectively. A group of 15 normally growing children and adolescents was also included.

RESULTS

Height-velocity standard deviation score (HV)-SDS was lower and body mass index higher in GHD than ISS. Standardized IGF-I differed significantly by ANOVA among the three groups (p = 0.001). Multiple stepwise linear regression analysis with HV-SDS as dependent variable showed IGF-I SDS as the best predictor followed by peak GH clonidine response and uGH excretion. ROC curves showed optimum cut-off level for IGF-I SDS as 2.05 (sensitivity: 32%, specificity: 90%) and 1.14 for IGFBP-3 SDS sensitivity: 28%, specificity: 94%).

CONCLUSIONS

Standardized IGF-I and IGFBP-3 measurements were highly efficient only in diagnosis of severe GHD, but they show low sensitivity for the diagnosis of isolated idiopathic GHD as defined according to the low GH response to stimulation tests.

Analytical performance and clinical usefulness of two binding assays for growth hormone binding protein (GHBP) measurement: high performance liquid chromatography (HPLC)-gel filtration and dextran-coated charcoal adsorption

We compared two binding assays for growth hormone binding protein (GHBP) measurements, which differ in the method of bound and free GH separation: HPLC-gel filtration or dextran coated-charcoal adsorption (DCC). Two pools of sera (high and medium GHBP activity) were used for quality-control assessment. Moreover, 62 samples from 34 children and 28 adults with different nutritional status were studied. Total, between- and intra-iodination coefficients of variation (CVs) from the two methods were not different. Although percentage binding measured in the pool sera significantly differed, the concentrations assessed by Scatchard plot were comparable. Results obtained by the two methods in the 62 sera were significantly correlated (r = 0.77, P < 0.001). With both methods GHBP activity correlated with chronological age and body mass index (BMI) and differed among groups with different nutritional status. Although HPLC and DCC separation methods for GHBP measurement differ in their practicability, our study demonstrates that performance and the clinical usefulness of the two methods are comparable.

trans,trans-Muconic acid, a reliable biological indicator for the detection of individual benzene exposure down to the ppm level

trans,trans-Muconic acid (2,4-hexadienedioic acid) (t,t-MA) is a minor benzene metabolite which can be used as a biological indicator for benzene exposure. The purpose of the study was to evaluate the limits of use of t,t-MA for detection and quantification of occupational exposures to benzene, particularly on an individual scale, phenol being used as the metabolite of reference. A simple and sensitive method previously described by the authors was carried out to analyse t,t-MA in 105 end-of-shift urinary samples from 23 workers exposed to benzene used as an extraction solvent for "concretes" recovery in the perfume industry. Good correlations were found between atmospheric benzene and both metabolites (uncorrected or corrected for creatinine) or between the metabolites themselves, with correlation coefficients from 0.81 to 0.91 (P < 0.0001). Correlation- coefficients were not improved after correction for creatinine. The overall individual benzene exposure range, median, and arithmetic mean were respectively 0.1-75, 4.5, and 9.0 ppm with corresponding t,t-MA excretion of 0.1-47.9, 5.2 and 8.9 mg/l (uncorrected) and phenol excretion of 1.4-298, 30.9, and 42.2 mg/l (uncorrected). In the control group (145 determinations for t,t-MA and 76 for phenol from 79 individuals) the range, median, and arithmetic mean were respectively < 0.04-0.66, 0.08, and 0.13 mg/l (uncorrected t,t-MA) and 1.5-42.0, 9.85 and 11.3 mg/l (uncorrected phenol). t,t-MA was far more specific than phenol and could be easily and practically used to estimate with a given probability the upper or lower corresponding benzene concentrations down to around the ppm level.(ABSTRACT TRUNCATED AT 250 WORDS)

Tympanometry and fistula test

The 'fistula test' is performed when an abnormal opening between the vestibule and the middle ear cavity is suspected. The fistula is usually seen after stapedectomy, but may also occur after trauma to a normal ear when the round window membrane may rupture. Tympanometry with an electronystagmographic (ENG) tracing may show a positive result after stapedectomy in the absence of a fistula, and there may conversely be a normal ENG tracing after tympanometry when there is in fact a perilymph fistula. The authors explain the reasons for this paradoxical response. In no way does it detract from the value of the test, which only needs to be interpreted correctly.

[Action of domperidone on dopamine-induced inhibition of gastric secretion]

The inhibitory action of dopamine on basal gastric secretion and that stimulated by pentagastrin with previous administration of domperidone in 26 male patients, between 18 and 48 years of age, suffering duodenal ulcer has been studied. The administration of domperidone (0.25 mg/kg) produces a significant reduction of the inhibitory action of dopamine on basal gastric secretion and that stimulated by pentagastrin at dose 0.15 microgram/kg/h. Besides dopamine shows a minor, non significant, inhibitory action on acid gastric secretion stimulated by maximal doses of pentagastrin, while showing no differences against the group without administration of domperidone.

Multifrequency impedance testing in relation to otospongiotic stapedial fixation and other factors

After reviewing COLLETTI'S research, the authors describe their own experimental work on multifrequency impedance testing in relation to stapedial fixation in otospongiosis, and other factors. Their findings, based on 266 tested ears, lead the authors to the conclusion that : (1) the most useful frequencies, from the clinical point of view, are the low ones (220, 660 and 800 Hz); (2) the research frequencies, range beyond (900 to 2 000 Hz), for a finer diagnosis, but are confused by numerous artefacts and are not always reliable; (3) COLLETTI'S conclusions on the inversion of the peak and on the shifting of M and W, are valuable, but not always reliable in some cases.

[Impedancemetry. Clinical applications]

The authors call attention to the importance of the data provided by impendancemetry, both in its classified applications, by tympanogram, and in impedance-audiometry, by the study of elicited stapedius reflex. They warn against the tendency to consider impedancemetry as a synonym for examination in conductive deafness and to reserve impedance-audiometry exclusively for perceptive deafness. These two techniques must be coupled and their multiple clinical applications are very often intricated. Tympanograms based in their clinic on the study of relative impedance, provide equally interesting diagnostic data in post-otorrhea states with open eardrum as well as closed eardrum for which until now tympanogram was the classic test. Of course tubal disfunctions, serous effusions of the middle-ear, fibro-adhesive otitis and ossicles disruptions are part of the current diagnosis clarified by impedancemetry in conductive deafness. On the other hand, for otospongiosis, the tympanogram is not of absolute value, but impedancemetry permits an extremely interesting diagnosis in three cases: in associated syndroms, where it acts as warning before the operation; in airbone gap reopenings after surgery, where the knowledge of the precise etiology conditions the therapy;-- and in postoperative cochlear drops, where an easy differential diagnosis is allowed between perilymph fistula and labyrinthe hydrops. Impedance-audiometry is based on the elicitation of stapedius reflex. It has numerous applications in perceptive deafness, where the detection of recruitment is very easy and of great value. So the diagnosis between cochlear and retro-cochlear deafness may be made evident. This method also applies to conductive deafness, to crura ruptures, as well as to the diagnosis of the beginning of otospongiotic stapedial fixations by the detection of a typical on-off effect. Besides otospongiosis is one of the most paradoxical applications of impedance-audiometry, which is revealed to be richer in information than the study of compliance, masking problems, diagnosis of associated syndroms and early detection of the disease are easily solved by impedance-audiometry. For these many reasons, the authors insist once more upon the importance and value of the data provided by impedancemetry and impedance-audiometry. They specify that this method is the most interesting complement to classic audiometry since the appearance of the audiometer.

[Computer technology in otospongiosis. 2. Statistics on 15 years of stapedectomy]

To complete their two previous data processing studies on systematization of parameters for otospongiosis and on statistics concerning the otospongiotic disease itself, the authors now develop the study of postoperative functional results obtained over 15 years stapectomies performed according to various techniques. The characteristic of this study is that the functional results are not considered only from the operative technique point of view, but that they also take into account all the factors having an influence upon the functional results, i.e. mechanical operative factors, otospongiotic cochlear factors and, finally the patient's general factor. This work is divided in three parts. The first part considers statistical data drawn from investigating elements taken over a period ranging from 1960 to 1975 from operative findings, surgical techniques and operative complications, particularly during reoperations, i.e., the mechanical part of hearing improvement in otospongiosis surgery. The second part deals with the problem of the medical postoperative care in stapedial surgery and with that of postoperative complications and the therapy used to combat them. It is the study of the cochlear support problem considering both the cochlear fragility facing the operative trauma, and the cochlear deterioration due to the enzymatic action of the otospongiotic microfoci of the lateral wall of the cochlear duct and of the vestibular side of the footplate. The third part is the statistical study made both by means of data processing and of manual investigation, on the long term functional results obtained, on one hand by the surgical solution of the stapedial fixation's mechanical problem, and on the other, by the medical solution of the cochlear problem considered both from the enzymatic and vascular point of view. This study of stapedectomies' long term functional results allows the authors to draw the conclusions which seem to result logically from this very elaborated statistical study concerning near 17000 stapedectomies performed from 1960 through 1975.

Mechanical explanation of the on-off effect (diphasic impedance change) in otospongiosis

Impedancemetry gives important information in otospongiosis, both for relative compliance and impedance audiometry. The detection of the stapedius reflex is facilitated by recruitment in some audiometric types of otospongiosis and enables us to solve many of the masking problems which are particularly difficult in this disease due to the very important cross-hearing (or cross-over). Diphasic impedance changes (on-off effect) once detected must be systematically investigated since they allow us to detect otospongiosis early on. This sign is absolutely characteristic of the onset of a stapediovestibular involvement and is of primary interest in this disease because of its early appearance - before any classical audiometric change and any air-bone gap, i.e. before deafness. Diphasic impedance changes must thus be systematically investigated in case of so-called unilateral otospongiosis, in the audiometrically normal ear, and for the detection of otospongiosis in otospongiotic families. It is also helpful in confirming the otospongiotic origin of sensorineural losses before an air-bone gap appears. Our experience with routine stapedectomies and impedance audiometry measurements have led us to a purely mechanical explanation of the on-off effect, i.e. the response of an elastic system to a deformation with a different mechanism of the two inverse peaks, with a different mass and thus a different inertia. This mechanical explanation fits perfectly with anatomical findings. Everything occurs as if the evolutive stages of the onset of the stapediovestibular involvement were defined in impedancemetry, starting from the normal stapedius reflex, first by mixed forms, then by a pure on-off effect, finally by the disappearance of the stapedius reflex.

[Contribution of data processing in otospongiosis. Part I. Statistics on otospongiosis]

The use of data processing in their otology clinic allowed the authors a better approach to otospongiosis and to its treatment, thus completing the knowledge of the otospongiotic disease according to their enzymatic concept. An important material has been gathered since 1959 to the present (June 1, 1974), based on more than 16 000 stapedectomies and nearly 100 000 otology out-patients. It has been studied both through a conventional method and an informatic one on the computer of their clinic. Statistical data, apparently valuable, could be drawn from this mass of information for each patient, starting from his first consultation and following him through his secondary consultations, operation, immediate postoperative follow-up and various postoperative check-ups performed. It also takes into account the general state of the patient and all the accidents which may happen during a remote postoperative period. First of all, the authors give the data for these statistics established according to the systematization of the parameters for otospongiosis they have previously published in 1973. In the first part, they gather statistical data obtained about the otospongiotic disease itself, some of which differ from the classical notions of frequency or importance. These statistical conclusions confirm some percentages stated by other authors (predominance of the woman and of the white race, severity of the disease in the young, etc.), but differ in relation to the number of deafs, the percentage of unilateral otospongiosis in comparison, to the bilateral ones, the importance of pure cochlear otospongiosis, the separate valuation of audiometric stages and that of anatomic types, the relation between age and anatomic type, finally the respective frequency of pre-and postoperative vertigos. In the second part, which will be presented later, the authors will study the postoperative functional results obtained within a period of 15 years by stapedectomy according to three techniques. But the particularity of this study will be the fact that functional results will not be considered only from the operative point of view, but from the whole of the factors acting upon the functional result, i.e.: operative mechanical factor, otospongiotic cochlear component, finally general state of the patient. We will thus have a better knowledge of this very peculiar disease of the otic capsule, hat is otospongiosis, characterized by its two phases: a first lytic phase provoked by an enzymatic factor, then a second rebuilding phase according to a pseudo haversian process. During the long progression of the disease, these two phases intermingle and juxtapose much more than they follow each other in the course of time.

Paradoxical compliances in otosclerosis

Results of impedancemetry have been compared with operative findings in 1 867 cases of otosclerosis, 1 583 of which were pure otosclerosis. This comparison indicated that: (1) with present techniques, the results of impedancemetry are only of a relative value in otosclerosis; it is thus necessary to asses the various connected anatomical elements in the middle ear with extreme rigor; (2) impedancemetry data have an absolute value in all disorders of the middle ear with closed eardrum associated with otosclerosis; (3) relative impedancemetry often gives informative results when it concurs with the other elements of clinical and audiometrical diagnosis; (4) impedancemetry data are a valuable element of early diagnosis of otosclerosis before the first audiometric expression, either by a lowering of compliance or, most of all, by appearance of an on-off effect (diphasic impedance change) or by disappearance of the stapedius reflex; (5) parallel or crossed paradoxical compliances are only apparently paradoxical and are usually the sign of either an early stapedo-vestibular fixation (before its audiometric expression) or an associated factor in the middle ear, both of which may have been unnoticed; (6) the problem of compliance value in otosclerosis will be solved only when the proper stapes frequency is found and when it is possible to test this frequency. This problem is the subject of our current research.