Peptide encoding Populus CLV3/ESR-RELATED 47 (PttCLE47) promotes cambial development and secondary xylem formation in hybrid aspen.

The CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (ESR)-RELATED (CLE) peptide ligands in connection with their receptors are important players in cell-to-cell communications in plants. Here, we investigated the function of the Populus CLV3/ESR-RELATED 47 (PttCLE47) gene during secondary growth and wood formation in hybrid aspen (Populus tremula × tremuloides) using an RNA interference (RNAi) approach. Expression of PttCLE47 peaks in the vascular cambium. Silencing of the PttCLE47 gene expression affected lateral expansion of stems and decreased apical height growth and leaf size. In particular, PttCLE47 RNAi trees exhibited a narrower secondary xylem zone with less xylem cells/cell file. The reduced radial growth phenotype also correlated with a reduced number of cambial cell layers. In agreement with these results, expression of several cambial regulator genes was downregulated in the stems of the transgenic trees in comparison with controls. Altogether, these results suggest that the PttCLE47 gene is a major positive regulator of cambial activity in hybrid aspen, mainly promoting the production of secondary xylem. Furthermore, in contrast to previously characterized CLE genes expressed in the wood-forming zone, PttCLE47 appears to be active at its site of expression.

WUSCHEL-RELATED HOMEOBOX4 (WOX4)-like genes regulate cambial cell division activity and secondary growth in Populus trees.

Plant secondary growth derives from the meristematic activity of the vascular cambium. In Arabidopsis thaliana, cell divisions in the cambium are regulated by the transcription factor WOX4, a key target of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (ESR)-RELATED 41 (CLE41) signaling pathway. However, function of the WOX4-like genes in plants that are dependent on a much more prolific secondary growth, such as trees, remains unclear. Here, we investigate the role of WOX4 and CLE41 homologs for stem secondary growth in Populus trees. In Populus, PttWOX4 genes are specifically expressed in the cambial region during vegetative growth, but not after growth cessation and during dormancy, possibly involving a regulation by auxin. In PttWOX4a/b RNAi trees, primary growth was not affected whereas the width of the vascular cambium was severely reduced and secondary growth was greatly diminished. Our data show that in Populus trees, PttWOX4 genes control cell division activity in the vascular cambium, and hence growth in stem girth. This activity involves the positive regulation of PttWOX4a/b through PttCLE41-related genes. Finally, expression profiling suggests that the CLE41 signaling pathway is an evolutionarily conserved program for the regulation of vascular cambium activity between angiosperm and gymnosperm tree species.

Identification of new adventitious rooting mutants amongst suppressors of the Arabidopsis thaliana superroot2 mutation.

The plant hormone auxin plays a central role in adventitious rooting and is routinely used with many economically important, vegetatively propagated plant species to promote adventitious root initiation and development on cuttings. Nevertheless the molecular mechanisms through which it acts are only starting to emerge. The Arabidopsis superroot2-1 (sur2-1) mutant overproduces auxin and, as a consequence, develops excessive adventitious roots in the hypocotyl. In order to increase the knowledge of adventitious rooting and of auxin signalling pathways and crosstalk, this study performed a screen for suppressors of superroot2-1 phenotype. These suppressors provide a new resource for discovery of genetic players involved in auxin signalling pathways or at the crosstalk of auxin and other hormones or environmental signals. This study reports the identification and characterization of 26 sur2-1 suppressor mutants, several of which were identified as mutations in candidate genes involved in either auxin biosynthesis or signalling. In addition to confirming the role of auxin as a central regulator of adventitious rooting, superroot2 suppressors indicated possible crosstalk with ethylene signalling in this process.

Sl-IAA3, a tomato Aux/IAA at the crossroads of auxin and ethylene signalling involved in differential growth.

Whereas the interplay of multiple hormones is essential for most plant developmental processes, the key integrating molecular players remain largely undiscovered or uncharacterized. It is shown here that a member of the tomato auxin/indole-3-acetic acid (Aux/IAA) gene family, Sl-IAA3, intersects the auxin and ethylene signal transduction pathways. Aux/IAA genes encode short-lived transcriptional regulators central to the control of auxin responses. Their functions have been defined primarily by dominant, gain-of-function mutant alleles in Arabidopsis. The Sl-IAA3 gene encodes a nuclear-targeted protein that can repress transcription from auxin-responsive promoters. Sl-IAA3 expression is auxin and ethylene dependent, is regulated on a tight tissue-specific basis, and is associated with tissues undergoing differential growth such as in epinastic petioles and apical hook. Antisense down-regulation of Sl-IAA3 results in auxin and ethylene-related phenotypes, including altered apical dominance, lower auxin sensitivity, exaggerated apical hook curvature in the dark and reduced petiole epinasty in the light. The results provide novel insights into the roles of Aux/IAAs and position the Sl-IAA3 protein at the crossroads of auxin and ethylene signalling in tomato.

[Polymorphous low-grade adenocarcinoma: about two cases]. / Adénocarcinome polymorphe de bas grade: à propos de deux cas.

BACKGROUND: Polymorphous low-grade adenocarcinoma (APBG) is a variant of malignant tumour of minor salivary glands usually arising in the palate. AIM: Our aim is to discuss morphology, evolution and differential diagnosis of this rare tumour. CASE REPORTS: The first case interested a 65-year-old-woman admitted for a two-months-history of a right submaxillary swelling. Examination found a tumour of the right side of the palate. A biopsy concluded to a pleomorphic adenoma. Giving that the mass enlarged, a surgical resection carrying off the thyroid with a bilateral neck dissection was performed. Diagnosis was an APBG partially resected with lymph node metastasis. The patient received adjuvant radiotherapy. Local recurrence appeared 28 months after treatment. The second case interested a 57-year-old-woman who consulted for a 12-year-history of a swelling of the lower lip. Clinical examination showed a painless nodule measuring 2 cm located in the mucosal side of the lower lip. An excisional biopsy was performed. Pathologic examination concluded to an APBG completely resected. The patient had no evidence of disease with a follow-up of 54 months. CONCLUSION: APBG is characterised by a morphologic diversity and a cytologic uniformity that may cause a diagnostic dilemma especially with adenoid cystic carcinoma and pleomorphic adenoma. Its aggressiveness is assessed by its local infiltrative growth pattern requiring a wide surgical excision.

Impacts of nutritional education before Ramadan fasting on dietary intake, weight and body composition in diabetic patients.

BACKGROUND: The fasting period of Ramadan requires special attention for diabetic patients in particular. AIM: To determine the impacts of a nutritional education program before Ramadan fasting (RF) on dietary intake, anthropometry and body composition. METHODS: This was an interventional and comparative study including 54 type 2 diabetic patients, recruited at the National Institute of Nutrition. The patients were divided into two groups: an educated group who received a nutritional education session before Ramadan (n=26), and an uneducated group who did not receive any education (n=28). Food survey, anthropometry and body composition measurements were conducted before and after the month of Ramadan. RESULTS: During RF, a significantly decrease in carbohydrate intake was observed in both educated and uneducated patients (∆=-4.1 vs. ∆=-6.25). Lipid intake was increased significantly during RF for all patients. This increase was lower in patients receiving education compared to the other group (3.4±7.43 vs. 5.25±5.7). During RF, a significant increase in protein, saturated and monounsaturated fatty acids intake was shown in the uneducated group compared to educated group (respectively, ∆=1.19±2.30 vs. ∆ =1.06±7.10, ∆=3.40±7.43 vs. ∆=5.25±5.70 and ∆=2.23±5.60 vs. ∆=2.31±5.10). The weight loss was similar between the two groups of educated (-1.05 kg) and uneducated (-0.58 kg) patients. There was no significant change in body composition during Ramadan in both groups of diabetics. CONCLUSIONS: Nutritional education programs positively impact diabetic patients who prefer RF or insist to fast during Ramadan. These programs must be provided to diabetics before Ramadan.

A Molecular Framework for the Control of Adventitious Rooting by TIR1/AFB2-Aux/IAA-Dependent Auxin Signaling in Arabidopsis.

In Arabidopsis thaliana, canonical auxin-dependent gene regulation is mediated by 23 transcription factors from the AUXIN RESPONSE FACTOR (ARF) family that interact with auxin/indole acetic acid repressors (Aux/IAAs), which themselves form co-receptor complexes with one of six TRANSPORT INHIBITOR1/AUXIN-SIGNALLING F-BOX (TIR1/AFB) proteins. Different combinations of co-receptors drive specific sensing outputs, allowing auxin to control a myriad of processes. ARF6 and ARF8 are positive regulators of adventitious root initiation upstream of jasmonate, but the exact auxin co-receptor complexes controlling the transcriptional activity of these proteins has remained unknown. Here, using loss-of-function mutants we show that three Aux/IAA genes, IAA6, IAA9, and IAA17, act additively in the control of adventitious root (AR) initiation. These three IAA proteins interact with ARF6 and/or ARF8 and likely repress their activity in AR development. We show that TIR1 and AFB2 are positive regulators of AR formation and TIR1 plays a dual role in the control of jasmonic acid (JA) biosynthesis and conjugation, as several JA biosynthesis genes are up-regulated in the tir1-1 mutant. These results lead us to propose that in the presence of auxin, TIR1 and AFB2 form specific sensing complexes with IAA6, IAA9, and/or IAA17 to modulate JA homeostasis and control AR initiation.

[Intimal sarcoma of the aorta: a case report]. / Sarcome intimal de l'aorte: une observation.

Primary aortic tumours are very rare. To our knowledge, only 120 cases had been reported in the world literature. Their clinical presentation is not specific. They are usually diagnosed at aortic surgery or by post-mortem examination. Intimal sarcoma is the most frequent histological type. We report a case of intimal sarcoma of the thoracic aorta diagnosed on autopsy of a 48-year-old man victim of sudden death. The main problem raised by intimal sarcoma lies in its poor differentiation or lack of differentiation. Thus, the pathologist must perform a phenotypic analysis as complete as possible of this tumor.

Evaluation of tumor-free distance and depth of myometrial invasion as prognostic factors in endometrial cancer.

The aim of the study was to investigate whether the tumor free distance (TFD), which is the distance in millimeters between the deepest point of invasion and the serosal surface, and absolute depth of invasion (DMI), the distance in millimeters between the endomyometrial junction and the deepest point of myometrial invasion, are useful in surgical staging and in predicting prognosis. The present study retrospectively analyzed 62 cases of endometrial carcinoma with complete surgical staging, carried out over a 4 and half-year period (January 2003 to June 2007). All surgicopathological findings including surgical stages, histological type and grade, myometrial invasion, lymphovascular space invasion, cervical and adnexal involvement, and lymph node metastasis were abstracted from medical records and pathological reports. Univariate and multivariate analyses were performed comparing TFD, DMI and the percentage of mypmetrial invasion (MI) with established prognostic factors. A total of 62 patients were included in the study. A total of 52 (84%) had endometrioid carcinomas and 31 patients (60%) had grade 1 cancer. The deepest MI was <50% in 32 patients (52%). Median DMI was 2.7 mm (range 0-15 mm). Median TFD was 3 mm (range 0-19 mm). There was lymphovascular space invasion (LVSI) in 11 patients (17.5%), cervical involvement in 11 patients (17.5%), extra-uterine extension in 9 cases (14%) and lymph node metastasis in 12 patients (22%). It was demonstrated that 50% MI was significantly associated with prognostic factors (cervical involvement, type 2 carcinomas and LVSI, and was a significant predictor of the 5-year overall survival rate and recurrence-free survival (P=0.05, P=0.01). No significant association was observed between DMI and TFD with clinicopathological parameters and survival rates. The importance of DMI in predicting recurrence of disease was observed to be highest in terms of sensitivity and specificity. The cut-off value with the highest sensitivity and specificity crossing the receive operating characteristic curve was calculated to be 3 mm for DMI and 2.5 mm for TFD. The results indicate that DMI is a superior predictive factor of recurrence of the disease compared with TFD. However, further studies are required in order to prove the prognostic usefulness of these parameters and then to improve management of endometrial cancer.

Identification and functional characterization of two HOOKLESS genes in Tomato (Solanum lycopersicum).

The apical hook of dark-grown dicotyledonous plants results from asymmetric growth of the inner and outer sides of the upper part of the hypocotyl. This protective structure prevents damage of the shoot apical meristem and the young leaves as the seedling pushes through the soil. HOOKLESS (HLS1) of Arabidopsis was recognised as an ethylene response gene whose product is required for hook formation. We cloned two cDNAs from tomato, Sl-HLS1 and Sl-HLS2, and showed through the complementation of the Arabidopsis hls1 mutant that the encoded proteins are functional orthologs of At-HLS1. The genomic clones of Sl-HLS1 and Sl-HLS2 showed similar structure with two introns and three exons. While the data indicate complete functional redundancy between the two tomato HLS genes, only the expression of Sl-HLS2 is regulated by ethylene and auxin and the ethylene-induced expression of Sl-HLS2 is localised in the outer side of the hook while the auxin-responsive expression is not restricted to a specific side of the hook. 1-MCP, an inhibitor of ethylene signalling, inhibited auxin-enhanced accumulation of Sl-HLS2 mRNA in the apical hook suggesting that regulation of Sl-HLS2 by auxin is ethylene-dependent. The overexpression of tomato Sl-HLS1 and Sl-HLS2 in Arabidopsis confers hypersensitivity to ethylene. The data presented bring further insight into the complex ethylene-auxin interplay in hook formation.

Correlation Between Immunohistochemical Biomarkers Expression and Prognosis of Ovarian Carcinomas in Tunisian Patients.

BACKGROUND: Ovarian cancer is the leading cause of death from gynaecological malignancies. Newer biological prognostic factors and predictors of response to therapy are needed. Our study was designed to evaluate the expression of p53, Bcl-2, Estrogen receptor (ER) and Progesterone receptor (PR) in ovarian carcinoma and to compare it with other prognostic parameters such as age, FIGO stage, size of residual tumor, histological type and grade. METHODS: This is a retrospective study conducted in the department of pathology at Sfax University Hospital. Confirmed 57 cases of ovarian carcinoma were reviewed in the period between January 1995 and December 2006. We used immunohistochemistry to evaluate the expression of p53, Bcl-2, ER and PR receptors and Chi-Square and Student test to correlate immunohistochemical findings with some prognostic parameters of ovarian carcinoma. RESULTS: The percentage of expression of p53, Bcl-2, ER and PR was 73,7; 47,4; 35,1 and 33,3 % respectively. p53 overexpression correlated with an advanced FIGO stage (p = 0,026) and presence of ascitis (p < 10-4). The expression of PR was associated with an early stage (FIGO I and II), a non serous histologic type and a low tumour grade (p = 0,045; 0,010 and 0,036 respectively). No correlation was found between Bcl-2 and ER and prognostic parameters. Survival analysis revealed that Bcl-2 status, FIGO stage, presence of ascites, peritoneal cytology, and residual disease were significant predictive factors of survival. CONCLUSION: p53 expression correlates with a worse prognosis in epithelial ovarian cancer, whereas Bcl-2 expression is related to a better outcome. For hormonal status, expression of PR is found to be an independent indicator of favourable prognosis. These results should be supported by more and larger studies.

The tomato Aux/IAA transcription factor IAA9 is involved in fruit development and leaf morphogenesis.

Auxin/indole-3-acetic acid (Aux/IAA) proteins are transcriptional regulators that mediate many aspects of plant responses to auxin. While functions of most Aux/IAAs have been defined mainly by gain-of-function mutant alleles in Arabidopsis thaliana, phenotypes associated with loss-of-function mutations have been scarce and subtle. We report here that the downregulation of IAA9, a tomato (Solanum lycopersicum) gene from a distinct subfamily of Aux/IAA genes, results in a pleiotropic phenotype, consistent with its ubiquitous expression pattern. IAA9-inhibited lines have simple leaves instead of wild-type compound leaves, and fruit development is triggered before fertilization, giving rise to parthenocarpy. This indicates that IAA9 is a key mediator of leaf morphogenesis and fruit set. In addition, antisense plants displayed auxin-related growth alterations, including enhanced hypocotyl/stem elongation, increased leaf vascularization, and reduced apical dominance. Auxin dose-response assays revealed that IAA9 downregulated lines were hypersensitive to auxin, although the only early auxin-responsive gene that was found to be upregulated in the antisense lines was IAA3. The activity of the IAA3 promoter was stimulated in the IAA9 antisense genetic background, indicating that IAA9 acts in planta as a transcriptional repressor of auxin signaling. While no mutation in any member of subfamily IV has been reported to date, the phenotypes associated with the downregulation of IAA9 reveal distinct and novel roles for members of the Aux/IAA gene family.