[Delayed puberty with extreme uterine hypotrophy: do not conclude too early to the absence of the uterus]. / Retard pubertaire avec hypotrophie utérine majeure: ne pas conclure trop vite à l'absence d'utérus.

OBJECTIVE: To emphasize the difficulties to distinguish between uterine agenesis and extreme uterine hypotrophy in the context of primary amenorrhoea with delayed puberty. PATIENTS AND METHODS: Among adolescents who consulted with our center because of primary amenorrhoea, from 1997 to 2005, three patients were referred for a suspicion of Mayer-Rokitansky-Kuster-Hauser Syndrome, after ultrasonography had failed to visualize the uterus. The 3 patients underwent endocrine and genetic evaluations. Transabdominal ultrasonography and MRI performed pelvic examination. Patients were placed under estrogen treatment. RESULTS: Endocrine evaluation indicated primary ovarian failure for patient 1, and hypogonadotrophic hypogonadism for patients 2 and 3. Karyotype was 46,XX in all patients. Initial pelvic ultrasonography revealed the absence of uterus. MRI allowed visualizing prepubertal uterus for patient 1, a hypotrophic uterus for patient 3 and concluded to uterine agenesis for patient 2. In all cases estradiol substitutive therapy induced uterine growth and confirmed retrospectively the diagnosis of extreme uterine hypotrophy. DISCUSSION AND CONCLUSION: Pelvic ultrasonography can be misleading in the evaluation of primary amenorrhoea. No visualization of uterus on ultrasonography can occur in the context of delayed puberty and should not induce a premature diagnosis of Mayer-Rokitansky-Kuster-Hauser syndrome. Indeed, such a diagnosis has therapeutic, reproductive and psychological consequences.

[Rotterdam consensus in adolescent girls: which investigations and how to interpret them to make the diagnosis of PCOS?]. / Le consensus de Rotterdam appliqué à l'adolescente: quels examens prescrire et comment les interpréter pour établir le diagnostic de SOPK?

The polycystic ovary syndrome (PCOS) is the most frequent cause of hyperandrogenism and anovulation in adult women as well as in adolescent girls. Since 2003 the diagnosis of PCOS has been based on the association of hyperandrogenism, oligoanovulation and polycystic ovary (PCO) morphology at ultrasound (at least 2 items out of 3). In adolescents however, PCOS features may be difficult to distinguish from the symptoms of the end of puberty. Moreover, transvaginal ultrasound examination is seldom possible, and it is difficult to get precise imaging of the ovaries by abdominal route. However, the diagnosis of PCOS in a hyperandrogenic and/or oligomenorrheic adolescent requires on the strict application of the Rotterdam criteria, as in adult women. Priority should be given to clinical features whereas pelvic ultrasound must be considered as optional. Few hormonal assays will serve mainly to make the differential diagnosis, in addition to clinical findings. Once established, the diagnosis of PCOS in an adolescent girl must lead to the detection of the metabolic syndrome by means of simple investigations. This will allow early prevention of its complications.

[Revelation of a polymicrocystic ovary syndrome after one month's treatment by pulsatile GnRH in a patient presenting with functional hypothalamic amenorrhea]. / Révélation d'un syndrome des ovaires polymicrokystiques après un mois de traitement par GnRH pulsatile chez une patiente présentant une aménorrhée hypothalamique fonctionnelle.

Polycystic ovary syndrome (PCOS) and hypothalamic amenorrhea (HA) are the most frequent causes of endocrine infertility, but their association is an uncommon occurrence. We report the case of a 28-year old woman suffering from infertility and amenorrhea. Her weight was normal (BMI = 19) and she had no hirsutism. She self-reported food restriction and a 10 kg weight loss 5 years ago, concomitant with the onset of amenorrhea. At the initial evaluation, the patient was considered as having HA due to food restriction. At ultrasonography, ovaries were small and multifollicular (right and left area: 2.2 and 2.5 cm(2), respectively; number of cysts 2-9 mm in diameter: 15 and 12, respectively), and no stromal hypertrophy was noted. She has been treated for 1 month by intravenous pulsatile GnRH administration. Although the doses were increased from 5 to 15 microg/pulse every 90 min, no E2 response and no follicular development were observed. Hormonal re-evaluation revealed normal levels of serum LH, FSH and androgens, and a normal LH/FSH ratio. However, a typical aspect of PCO was found at ultrasound (right and left area: 6.5 and 5.5 cm(2), respectively, and more than 15 small cysts arranged peripherally around an increased central stroma in each ovary). The treatment has been then switched to hMG, using the low dose step-up regimen and starting with 75 U/day. In the absence of response after 2 weeks, the dose was increased to 112.5 U/day and a multifollicular reaction occurred, leading to cancellation. In conclusion, we hypothesize that this patient had a "hidden" PCOS when she was hypogonadotrophic and that it developed very rapidly after restitution of a normal gonadotropin level under exogenous GnRH. This occurred despite a low insulin level, showing that hyperinsulinism is not a prerequisite for the development of PCOS in every case.

Maize genes encoding the small subunit of ADP-glucose pyrophosphorylase.

Plant ADP-glucose pyrophosphorylase (AGP) is a heterotetrameric enzyme composed of two large and two small subunits. Here, we report the structures of the maize (Zea mays) genes encoding AGP small subunits of leaf and endosperm. Excluding exon 1, protein-encoding sequences of the two genes are nearly identical. Exon 1 coding sequences, however, possess no similarity. Introns are placed in identical positions and exhibit obvious sequence similarity. Size differences are primarily due to insertions and duplications, hallmarks of transposable element visitation. Comparison of the maize genes with other plant AGP small subunit genes leads to a number of noteworthy inferences concerning the evolution of these genes. The small subunit gene can be divided into two modules. One module, encompassing all coding information except that derived from exon 1, displays striking similarity among all genes. It is surprising that members from eudicots form one group, whereas those from cereals form a second group. This implies that the duplications giving rise to family members occurred at least twice and after the separation of eudicots and monocot cereals. One intron within this module may have had a transposon origin. A different evolutionary history is suggested for exon 1. These sequences define three distinct groups, two of which come from cereal seeds. This distinction likely has functional significance because cereal endosperm AGPs are cytosolic, whereas all other forms appear to be plastid localized. Finally, whereas barley (Hordeum vulgare) reportedly employs only one gene to encode the small subunit of the seed and leaf, maize utilizes the two genes described here.

Expression of ADP-glucose pyrophosphorylase in maize (Zea mays L.) grain and source leaf during grain filling.

The time course of ADP-glucose pyrophosphorylase activity and of starch accumulation rate measured in grain, from pollination to maturity, in Zea mays L. plants grown outdoors, was coincident for 2 years. No such correlation was observed in the adjacent leaf, which, furthermore, presented large year-to-year differences in starch accumulation pattern. Analysis of the expression of ADP-glucose synthase at the protein levels, using antibodies directed against the Bt2 or Sh2 subunits, established that the variation of activity in the grain was explained by parallel changes in the content of both subunits. The cDNA for Bt2 and Sh2 subunits were used as probes to quantify the corresponding messenger. In grain, the time course of Bt2 and Sh2 mRNA accumulation anticipated, with a similar pattern, the specific peptide variations, which suggests a transcriptional control of expression. By contrast, the control of leaf activity by protein content was less obvious than in the grain, and changes in leaf enzyme specific activity were suggested during the first 20 d after pollination. A clone homologous to the grain Bt2 subunit cDNA was isolated from a maize leaf cDNA library, and a sequence comparison showed that the leaf clone (L2) was a partial cDNA representing one-third of the mature peptide. A 97% homology was observed between Bt2 and L2 in their coding region, but homology was poor in the 3' noncoding border. This result demonstrates that Bt2 and L2 arise from different genes presenting a tissue-specific expression pattern and provides an explanation for the earlier reported differences between leaf and grain in the size of peptide and mRNA for the Bt2-homologous subunit.

Genetic Variability in Carbon Fixation, Sucrose-P-Synthase and ADP Glucose Pyrophosphorylase in Maize Plants of Differing Growth Rate.

The net photosynthetic rate and the activities of ribulose 1,5 bisphosphate carboxylase (RubisCo), phosphoenolpyruvate carboxylase, sucrose-P-synthase, and ADP glucose-pyrophosphorylase, key enzymes of the leaf carbohydrate metabolism were compared in eight maize (Zea mays L.) genotypes presenting large differences in growth rate. The sucrose-P-synthase activity varied in the ratio 1 to 3 from the less active to the more active genotype and this variation was highly correlated with those in growth rate. ADP glucose pyrophosphorylase activity was not significantly different from one genotype to another whatever the basis for expression, leaf area, or soluble protein. The photosynthetic rate varied with similar amplitude (1:1) to the RubisCo activity or RubisCo quantity but the correlation with growth rate was highly significant for photosynthesis and nonsignificant for RubisCo or phosphoenolpyruvate carboxylase. So, in our series of genotypes the sucrose synthesis capacities as expressed by sucrose phosphate synthase activity seem to have a good predicting value for mean growth rate at a young stage.

Rapid variations in the content of the RNA of the small subunit of ribulose-1,5-bisphosphate carboxylase of mature tobacco leaves in response to localized changes in light quantity. Relationships between the activity and quantity of the enzyme.

Mature green leaves from tobacco (Nicotiana tabacum L.) plants were submitted to contrasting light conditions; half of each leaf was shaded (changed from 60 to 25 µmol photons· m(-2) ·s(-1)=LL) and the other half was exposed to higher light (changed from 60 to 360 µmol·m(-2)· s(-1)=HL) for 24 h. The activity and quantity of ribulose-1,5-bisphosphate carboxylase (RuBPCase) were measured during the first 24 h in each leaf region and the variation was compared with that of small subunit (SSU)-and large subunit (LSU)-mRNA contents determined by a hybridot technique. Each leaf half responded separately to the actual light received. The activity of RuBPCase increased progressively in the HL zones and decreased in the LL zones. The RuBPCase-protein content was not significantly modified during the first 24 h but SSU-mRNA content responded very rapidly to the treatment. Within 2 h a significant difference in SSU mRNA appeared between LL and HL zones: at the end of the photoperiod the content in LL zones was approx. 25% of the initial value. The increase in the exposed zone, however, was not significant, indicating that there was a dissymmetry of the response to variation in incident white light. The LSU-mRNA contents from the same leaf extracts were totally unaffected by the light treatment. No day-night variations were noted in either SSU or LSU mRNAs in control plants.

Acclimation of Ribulose Bisphosphate Carboxylase and mRNAs to Changing Irradiance in Adult Tobacco Leaves: Differential Expression in LSU And SSU mRNA.

The transfer of Nicotiana tabacum plants grown in low light (60 micromoles quanta per square meter per second) to higher light (360 micromoles quanta per square meter per second) was previously shown to induce adaptive stimulation of photosynthetic capacities. The variations of ribulose bisphosphate carboxylase/oxygenase (RubisCo) expression in mature leaves was examined as a result of this acclimation. Maximum or initial activities increased markedly after low- to high-light transfer with a maximum effect after 2 to 3 days. The higher activity is mainly explained by RubisCo protein synthesis as shown by immunorocket technique. Small subunits of RubisCo (SSU) mRNA relative content determined by hybridization of total RNA with DNA probe by Dot-blot method, followed the same pattern as RubisCo quantity. The magnitude of this response was amplified when more contrasting light conditions (25 versus 360 micromoles per square meter per second) were established on the same leaf: RubisCo activity, RubisCo protein, and SSU mRNA contents decreased in the shaded zone and increased in the high-light zone within 1 day. After 2 days the shade/light ratio was 1 to 3 for RubisCo protein and 1 to 4 for SSU-RNA, whereas the ratios remained equal to one in controls. Hybridization of the same RNA extracts with large subunits of RubisCo (LSU) probe showed no variation in LSU-RNA content. So in green adult leaves, the expression of SSU and LSU genes is regulated differently. The observed white light quantitative effect on RubisCo expression was not dependent on the photosynthetic rate or assimilate content since low CO(2) concentration around the leaf after the light shift did not modify the response.

Interaction between External and Internal Conditions in the Development of Photosynthetic Features in a Grass Leaf: I. REGIONAL RESPONSES ALONG A LEAF DURING AND AFTER LOW-LIGHT OR HIGH-LIGHT ACCLIMATION.

Morphological and functional features were compared along a developing third leaf and fully expanded leaf from high-light- and low-light-acclimated seedlings of Lolium multiflorum.The young leaf contains a gradient of differentiating tissue, ranging from meristematic cells at the leaf base to mature tissue at the tip; this gradient can be related to the maturation of a functional photosynthetic apparatus. Along the fully expanded leaf, a decreasing gradient from tip to base is maintained for functional characteristics (net maximum photosynthesis, chlorophyll content, and ribulose bisphosphate carboxylase activity) and for a number of structural parameters (number of mesophyll cells and their external surface area, number of chloroplasts and their envelope area), irrespective of the light regime. In contrast, a constancy in the absolute intrachloroplastic lamellar content per plastid was revealed whatever the position in the leaf or irradiance received. However, the relative membrane content was lower in high-light chloroplasts due to their larger volume compared to low-light plastids (dilution effect).The longitudinal differences in functional and morphological characteristics are interpreted as the result of interaction between the internal gradient of differentiating tissue along a developing young leaf and the external light conditions during development.

Interaction between External and Internal Conditions in the Development of Photosynthetic Features in a Grass Leaf: II. REVERSIBILITY OF LIGHT-INDUCED RESPONSES AS A FUNCTION OF DEVELOPMENTAL STAGES.

Lolium multiflorum plants were grown under a low- or high-light regime until third leaves had emerged to one-third their final length and then were transferred to a contrasting light regime. At this stage, the leaf possesses a tissue-age gradient from tip to base; thus, the reversibility of light-acclimated responses as a function of the degree of differentiation was analyzed in individual leaves.Regional responses in the apical, medial, and basal zones of leaves of transferred plants were analyzed before and after light transfer and compared to leaves from plants kept in constant light. Leaves transferred from low to high light showed rapid recovery and attained light-saturated rates and ribulose bisphosphate carboxylase activities equivalent to those of high-light controls. However, fresh or dry weight and chlorophyll content were intermediate between those for the two irradiances. In the reciprocal experiment, the apical leaf zone retained high-light characteristics for maximum photosynthesis, whereas all the other functional parameters adapted rapidly to values characteristic of their low-light counterparts (equivalent foliar zones).On the ultrastructural level, chloroplasts in the apical zone of transferred leaves surpassed their respective constant light controls in absolute membrane content and size. However, a shift to high light induced an increase in plastid volume and, in relative terms, the plastid membrane content was diluted. A shift to low-light treatment led to smaller membrane-dense plastids. The ultrastructural readaptation is realized through differential rates of increase in plastid volume and lamellar content. Proplastids (leaf base), or juvenile plastids having reached an intermediate developmental stage (leaf middle zone) at the time of transfer, took on characteristics of the latter light regime (equivalent to controls).These results provide evidence for rapid reacclimation processes under changing light regimes and suggest a capacity for regional light responses along the leaf.

[Influence of very short photoperiods on the growth, pigment composition and chloroplast ultrastructure of Lolium multiflorum]. / Influence des héméropériodes très courtes sur la croissance de Lolium multiflorum, sa composition pigmentaire et l'ultrastructure chloroplastique.

We have described some characteristics of Lolium multiflorum cultivated under very short photoperiods (2 hours and 1 hour). The estimations of leaf growth were based on dry weight, surface measurements, and chlorophyll content. The pigment analyses were carried out by column chromatography; chloroplast ultrastructure was observed after chemical fixation.These measurements have permitted us to note a sharp drop in the growth curve of plants grown under different day-lengths: the limiting photoperiod lies between 1 hour and 2 hours of daily illumination.Pigment analyses and chloroplast ultrastructure observations show that there is a greater difference between plants cultivated under 1 hour and 2 hours of daily illumination than between plants cultivated under 2 hours and 12 hours.A decrease in day-length causes a deficit in the chlorophyll b content as well as a poor development of the grana.We have attempted to correlate these structural anomalies with the abnormal chlorophyll a/chlorophyll b ratio.