New insights into hydroxyectoine synthesis and its transcriptional regulation in the broad-salt growing halophilic bacterium Chromohalobacter salexigens.

Elucidating the mechanisms controlling the synthesis of hydroxyectoine is important to design novel genetic engineering strategies for optimizing the production of this biotechnologically relevant compatible solute. The genome of the halophilic bacterium Chromohalobacter salexigens carries two ectoine hydroxylase genes, namely ectD and ectE, whose encoded proteins share the characteristic consensus motif of ectoine hydroxylases but showed only a 51.9% identity between them. In this work, we have shown that ectE encodes a secondary functional ectoine hydroxylase and that the hydroxyectoine synthesis mediated by this enzyme contributes to C.␣salexigens thermoprotection. The evolutionary pattern of EctD and EctE and related proteins suggests that they may have arisen from duplication of an ancestral gene preceding the directional divergence that gave origin to the orders Oceanospirillales and Alteromonadales. Osmoregulated expression of ectD at exponential phase, as well as the thermoregulated expression of ectD at the stationary phase, seemed to be dependent on the general stress factor RpoS. In contrast, expression of ectE was always RpoS-dependent regardless of the growth phase and osmotic or heat stress conditions tested. The data presented here suggest that the AraC-GlxA-like EctZ transcriptional regulator, whose encoding gene lies upstream of ectD, plays a dual function under exponential growth as both a transcriptional activator of osmoregulated ectD expression and a repressor of ectE transcription, privileging the synthesis of the main ectoine hydroxylase EctD. Inactivation of ectZ resulted in a higher amount of the total ectoines pool at the expenses of a higher accumulation of ectoine, with maintenance of the hydroxyectoine levels. In addition to the transcriptional control, our results suggest a strong post-transcriptional regulation of hydroxyectoine synthesis. Data on the accumulation of ectoine and hydroxyectoine in rpoS and ectZ strains pave the way for using these genetic backgrounds for metabolic engineering for hydroxyectoine production.

The Role of Magnetic Resonance Imaging in the Pre-operative Evaluation of Women Diagnosed With Atypical Endometrial Hyperplasia.

BACKGROUND/AIM: To evaluate the role of MRI in patients with atypical endometrial hyperplasia (AEH) and incorporate MRI findings in predictive models estimating the risk of co-existent endometrial cancer (EC). PATIENTS AND METHODS: Data from 189 women diagnosed with AEH and had MRI scan prior to operation, over nine years, were retrospectively collected. RESULTS: Histology showed EC in 51 (27%) cases. Presence of myometrial invasion on MRI was more commonly detected in patients with EC compared to those with benign pathology (37.3% versus 10.9%, p<0.001). The sensitivity and specificity of MRI in identifying cancer were 37% and 89%, respectively. Age, menopausal status and presence of invasion on MRI were the best predictors for the presence of malignancy. CONCLUSION: Myometrial invasion on MRI is associated with increased risk of EC in women with AEH. Its accuracy in detecting malignancy improves when combined with clinical parameters. This could be of value for conservative-management candidates.

Cholecystectomy as Part of Cytoreductive Surgery for Advanced Ovarian Cancer: Perioperative Outcomes.

BACKGROUND/AIM: To assess the perioperative outcomes of cholecystectomy in cytoreductive procedures for epithelial ovarian cancer (EOC). PATIENTS AND METHODS: Prospectively collected perioperative data of patients that underwent cytoreduction for advanced EOC, between 2014 and 2018, were analysed. Patients were divided in two groups on the basis of whether cholecystectomy was performed. RESULTS: A total of 144 patients with stage IIIC/IV EOC were included. Cholecystectomy was performed in 22 (15.3%) patients. Those who underwent cholecystectomy more likely required diaphragmatic peritonectomy, splenectomy, lesser omentectomy, excision of disease from the porta hepatis and liver's capsule (p<0.001). There was no difference in the cytoreductive outcomes (complete or optimal) and the rate of grade 3-5 complications between the two groups (p=0.10 & p=0.06, respectively). No direct complications related to cholecystectomy were observed. CONCLUSION: A significant percentage of patients with advanced EOC require cholecystectomy. Gynecologic oncologists should embrace the opportunity to develop advanced surgical skills including cholecystectomy.

Fructose metabolism in Chromohalobacter salexigens: interplay between the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways.

BACKGROUND: The halophilic bacterium Chromohalobacter salexigens metabolizes glucose exclusively through the Entner-Doudoroff (ED) pathway, an adaptation which results in inefficient growth, with significant carbon overflow, especially at low salinity. Preliminary analysis of C. salexigens genome suggests that fructose metabolism could proceed through the Entner-Doudoroff and Embden-Meyerhof-Parnas (EMP) pathways. In order to thrive at high salinity, this bacterium relies on the biosynthesis and accumulation of ectoines as major compatible solutes. This metabolic pathway imposes a high metabolic burden due to the consumption of a relevant proportion of cellular resources, including both energy molecules (NADPH and ATP) and carbon building blocks. Therefore, the existence of more than one glycolytic pathway with different stoichiometries may be an advantage for C. salexigens. The aim of this work is to experimentally characterize the metabolism of fructose in C. salexigens. RESULTS: Fructose metabolism was analyzed using in silico genome analysis, RT-PCR, isotopic labeling, and genetic approaches. During growth on fructose as the sole carbon source, carbon overflow was not observed in a wide range of salt concentrations, and higher biomass yields were reached. We unveiled the initial steps of the two pathways for fructose incorporation and their links to central metabolism. While glucose is metabolized exclusively through the Entner-Doudoroff (ED) pathway, fructose is also partially metabolized by the Embden-Meyerhof-Parnas (EMP) route. Tracking isotopic label from [1-13C] fructose to ectoines revealed that 81% and 19% of the fructose were metabolized through ED and EMP-like routes, respectively. Activities of enzymes from both routes were demonstrated in vitro by 31P-NMR. Genes encoding predicted fructokinase and 1-phosphofructokinase were cloned and the activities of their protein products were confirmed. Importantly, the protein encoded by csal1534 gene functions as fructose bisphosphatase, although it had been annotated previously as pyrophosphate-dependent phosphofructokinase. The gluconeogenic rather than glycolytic role of this enzyme in vivo is in agreement with the lack of 6-phosphofructokinase activity previously described. CONCLUSIONS: Overall, this study shows that C. salexigens possesses a greater metabolic flexibility for fructose catabolism, the ED and EMP pathways contributing to a fine balancing of energy and biosynthetic demands and, subsequently, to a more efficient metabolism.

Quantitative RNA-seq Analysis Unveils Osmotic and Thermal Adaptation Mechanisms Relevant for Ectoine Production in Chromohalobacter salexigens.

Quantitative RNA sequencing (RNA-seq) and the complementary phenotypic assays were implemented to investigate the transcriptional responses of Chromohalobacter salexigens to osmotic and heat stress. These conditions trigger the synthesis of ectoine and hydroxyectoine, two compatible solutes of biotechnological interest. Our findings revealed that both stresses make a significant impact on C. salexigens global physiology. Apart from compatible solute metabolism, the most relevant adaptation mechanisms were related to "oxidative- and protein-folding- stress responses," "modulation of respiratory chain and related components," and "ion homeostasis." A general salt-dependent induction of genes related to the metabolism of ectoines, as well as repression of ectoine degradation genes by temperature, was observed. Different oxidative stress response mechanisms, secondary or primary, were induced at low and high salinity, respectively, and repressed by temperature. A higher sensitivity to H2O2 was observed at high salinity, regardless of temperature. Low salinity induced genes involved in "protein-folding-stress response," suggesting disturbance of protein homeostasis. Transcriptional shift of genes encoding three types of respiratory NADH dehydrogenases, ATP synthase, quinone pool, Na+/H+ antiporters, and sodium-solute symporters, was observed depending on salinity and temperature, suggesting modulation of the components of the respiratory chain and additional systems involved in the generation of H+ and/or Na+ gradients. Remarkably, the Na+ intracellular content remained constant regardless of salinity and temperature. Disturbance of Na+- and H+-gradients with specific ionophores suggested that both gradients influence ectoine production, but with differences depending on the solute, salinity, and temperature conditions. Flagellum genes were strongly induced by salinity, and further induced by temperature. However, salt-induced cell motility was reduced at high temperature, possibly caused by an alteration of Na+ permeability by temperature, as dependence of motility on Na+-gradient was observed. The transcriptional induction of genes related to the synthesis and transport of siderophores correlated with a higher siderophore production and intracellular iron content only at low salinity. An excess of iron increased hydroxyectoine accumulation by 20% at high salinity. Conversely, it reduced the intracellular content of ectoines by 50% at high salinity plus high temperature. These findings support the relevance of iron homeostasis for osmoadaptation, thermoadaptation and accumulation of ectoines, in C. salexigens.

Insights into metabolic osmoadaptation of the ectoines-producer bacterium Chromohalobacter salexigens through a high-quality genome scale metabolic model.

BACKGROUND: The halophilic bacterium Chromohalobacter salexigens is a natural producer of ectoines, compatible solutes with current and potential biotechnological applications. As production of ectoines is an osmoregulated process that draws away TCA intermediates, bacterial metabolism needs to be adapted to cope with salinity changes. To explore and use C. salexigens as cell factory for ectoine(s) production, a comprehensive knowledge at the systems level of its metabolism is essential. For this purpose, the construction of a robust and high-quality genome-based metabolic model of C. salexigens was approached. RESULTS: We generated and validated a high quality genome-based C. salexigens metabolic model (iFP764). This comprised an exhaustive reconstruction process based on experimental information, analysis of genome sequence, manual re-annotation of metabolic genes, and in-depth refinement. The model included three compartments (periplasmic, cytoplasmic and external medium), and two salinity-specific biomass compositions, partially based on experimental results from C. salexigens. Using previous metabolic data as constraints, the metabolic model allowed us to simulate and analyse the metabolic osmoadaptation of C. salexigens under conditions for low and high production of ectoines. The iFP764 model was able to reproduce the major metabolic features of C. salexigens. Flux Balance Analysis (FBA) and Monte Carlo Random sampling analysis showed salinity-specific essential metabolic genes and different distribution of fluxes and variation in the patterns of correlation of reaction sets belonging to central C and N metabolism, in response to salinity. Some of them were related to bioenergetics or production of reducing equivalents, and probably related to demand for ectoines. Ectoines metabolic reactions were distributed according to its correlation in four modules. Interestingly, the four modules were independent both at low and high salinity conditions, as they did not correlate to each other, and they were not correlated with other subsystems. CONCLUSIONS: Our validated model is one of the most complete curated networks of halophilic bacteria. It is a powerful tool to simulate and explore C. salexigens metabolism at low and high salinity conditions, driving to low and high production of ectoines. In addition, it can be useful to optimize the metabolism of other halophilic bacteria for metabolite production.

Understanding the interplay of carbon and nitrogen supply for ectoines production and metabolic overflow in high density cultures of Chromohalobacter salexigens.

BACKGROUND: The halophilic bacterium Chromohalobacter salexigens has been proposed as promising cell factory for the production of the compatible solutes ectoine and hydroxyectoine. This bacterium has evolved metabolic adaptations to efficiently grow under high salt concentrations by accumulating ectoines as compatible solutes. However, metabolic overflow, which is a major drawback for the efficient conversion of biological feedstocks, occurs as a result of metabolic unbalances during growth and ectoines production. Optimal production of ectoines is conditioned by the interplay of carbon and nitrogen metabolisms. In this work, we set out to determine how nitrogen supply affects the production of ectoines. RESULTS: Chromohalobacter salexigens was challenged to grow in media with unbalanced carbon/nitrogen ratio. In C. salexigens, overflow metabolism and ectoines production are a function of medium composition. At low ammonium conditions, the growth rate decreased importantly, up to 80%. Shifts in overflow metabolism were observed when changing the C/N ratio in the culture medium. 13C-NMR analysis of ectoines labelling revealed a high metabolic rigidity, with almost constant flux ratios in all conditions assayed. Unbalanced C/N ratio led to pyruvate accumulation, especially upon N-limitation. Analysis of an ect - mutant demonstrated the link between metabolic overflow and ectoine biosynthesis. Under non ectoine synthesizing conditions, glucose uptake and metabolic overflow decreased importantly. Finally, in fed-batch cultures, biomass yield was affected by the feeding scheme chosen. High growth (up to 42.4 g L-1) and volumetric ectoine yields (up to 4.21 g L-1) were obtained by minimizing metabolite overflow and nutrient accumulation in high density cultures in a low nitrogen fed-batch culture. Moreover, the yield coefficient calculated for the transformation of glucose into biomass was 30% higher in fed-batch than in the batch culture, demonstrating that the metabolic efficiency of C. salexigens can be improved by careful design of culture feeding schemes. CONCLUSIONS: Metabolic shifts observed at low ammonium concentrations were explained by a shift in the energy required for nitrogen assimilation. Carbon-limited fed-batch cultures with reduced ammonium supply were the best conditions for cultivation of C. salexigens, supporting high density growth and maintaining high ectoines production.

The impact of ultra-radical surgery in the management of patients with stage IIIC and IV epithelial ovarian, fallopian tube, and peritoneal cancer.

OBJECTIVE: The aim of this study is to estimate the percentage of patients with metastatic ovarian, fallopian tube, and primary peritoneal cancer requiring ultra-radical surgery to achieve cytoreduction to less than 1 cm (optimal) or no macroscopic residual disease (complete). METHODS: Perioperative data were collected prospectively on consecutive patients undergoing elective cytoreductive surgery for metastatic epithelial ovarian, fallopian tube, or primary peritoneal cancer at the Norfolk and Norwich University Hospital, a tertiary referral cancer centre in the United Kingdom from November 2012 to June 2016. RESULTS: Over a 42-month period, 135 consecutive patients underwent cytoreductive surgery for stage IIIC and IV ovarian, fallopian tube, or primary peritoneal cancer. The median age of the patients was 69 years. 47.4% of the patients underwent diaphragmatic peritonectomy and/or resection, 20% underwent splenectomy, 14.1% had excision of disease from porta hepatis and celiac axis, and 5.2% of the patients had gastrectomy. Cytoreduction to no macroscopic visible disease (complete) and to disease with greater tumour diameter of less than 1 cm (optimal) was achieved in 54.1 and 34.1% of the cases, respectively. Without incorporating surgical procedures in the upper abdomen ('ultra-radical'), the combined rate of complete and optimal cytoreduction would be only 33.3%. CONCLUSIONS: Up to 50.4% of the patients in this study required at least one surgical procedure classified as ultra-radical, emphasizing the importance of cytoreductive surgery in the upper abdomen in management of women with stage IIIC and IV ovarian, fallopian tube, and primary peritoneal cancer.

Investigating vaginal bleeding in postmenopausal women found to have an endometrial thickness of equal to or greater than 10 mm on ultrasonography.

PURPOSE: This aim of this study is to determine the risk of endometrial cancer in symptomatic postmenopausal women, when endometrial thickness on transvaginal ultrasonography is equal to or greater than 10 mm, and subsequent office-based endometrial sampling histology is negative. METHODS: This is a prospective cross-sectional study, performed in a gynaecological oncology centre in the United Kingdom between February 2008 and July 2012. All postmenopausal women presenting with vaginal bleeding were investigated using transvaginal ultrasonography. Women with endometrial thickness measurements equal to or greater than 10 mm and negative office-based endometrial biopsy underwent hysteroscopy and endometrial biopsies. RESULTS: Over a 52-month period, 4148 women were investigated for postmenopausal vaginal bleeding. 588 (14.2%) women were found to have endometrial thickness measurements of equal to or greater than 10 mm on transvaginal ultrasonography. 170 (28.9%) cases of endometrial cancer were diagnosed in this group: 149 (87.6%) of the cancer cases were diagnosed in the outpatient setting with a Pipelle® endometrial sampler, whilst 21 (12.4%) had a negative Pipelle® sample and were diagnosed with hysteroscopy. The group diagnosed with hysteroscopy had lower BMI (32.7 kg/m2 versus 39.7 kg/m2, p < 0.001) whilst the group diagnosed with Pipelle was more likely to have a history of hypertension and diabetes mellitus (p = 0.019 for both). The sensitivity of Pipelle was 87.65%. CONCLUSION: For women presenting with postmenopausal bleeding and where the endometrial thickness is equal to or greater than 10 mm and Pipelle sampling is negative, hysteroscopic evaluation with directed biopsy is strongly recommended.

Contribution of RpoS to metabolic efficiency and ectoines synthesis during the osmo- and heat-stress response in the halophilic bacterium Chromohalobacter salexigens.

Chromohalobacter salexigens is a halophilic γ-proteobacterium that responds to osmotic and heat stresses by accumulating ectoine and hydroxyectoine respectively. Evolution has optimized its metabolism to support high production of ectoines. We analysed the effect of an rpoS mutation in C. salexigens metabolism and ectoines synthesis. In long-term adapted cells, the rpoS strain was osmosensitive but not thermosensitive and showed unaltered ectoines content, suggesting that RpoS regulates ectoine(s)-independent osmoadaptive mechanisms. RpoS is involved in the regulation of C. salexigens metabolic adaptation to stress, as early steps of glucose oxidation through the Entner-Doudoroff pathway were deregulated in the rpoS mutant, leading to improved metabolic efficiency at low salinity. Moreover, a reduced pyruvate (but not acetate) overflow was displayed by the rpoS strain at low salt, probably linked to a slowdown in gluconate production and/or subsequent metabolism. Interestingly, RpoS does not seem to be the main regulator triggering the immediate transcriptional response of ectoine synthesis to osmotic or thermal upshifts. However, it contributed to the expression of the ect genes in cells previously adapted to low or high salinity.

Investigation and management of abnormal peri-menopausal bleeding.

Abnormal peri-menopausal bleeding is a common clinical problem. Decisions to investigate if the menstrual disorders are related to an underlying pathology or represent physiologic changes are often complex especially as no clear guidance is available. The aim of this review is to present a summary of the current available evidence regarding the investigation tools used to evaluate women with abnormal uterine bleeding during menopausal transition and in the post-menopausal period. In this article, we focus mainly on the investigation and exclusion of endometrial carcinoma, as this represents the most common malignancy diagnosed.

Role of central metabolism in the osmoadaptation of the halophilic bacterium Chromohalobacter salexigens.

Bacterial osmoadaptation involves the cytoplasmic accumulation of compatible solutes to counteract extracellular osmolarity. The halophilic and highly halotolerant bacterium Chromohalobacter salexigens is able to grow up to 3 m NaCl in a minimal medium due to the de novo synthesis of ectoines. This is an osmoregulated pathway that burdens central metabolic routes by quantitatively drawing off TCA cycle intermediaries. Consequently, metabolism in C. salexigens has adapted to support this biosynthetic route. Metabolism of C. salexigens is more efficient at high salinity than at low salinity, as reflected by lower glucose consumption, lower metabolite overflow, and higher biomass yield. At low salinity, by-products (mainly gluconate, pyruvate, and acetate) accumulate extracellularly. Using [1-(13)C]-, [2-(13)C]-, [6-(13)C]-, and [U-(13)C6]glucose as carbon sources, we were able to determine the main central metabolic pathways involved in ectoines biosynthesis from glucose. C. salexigens uses the Entner-Doudoroff pathway rather than the standard glycolytic pathway for glucose catabolism, and anaplerotic activity is high to replenish the TCA cycle with the intermediaries withdrawn for ectoines biosynthesis. Metabolic flux ratios at low and high salinity were similar, revealing a certain metabolic rigidity, probably due to its specialization to support high biosynthetic fluxes and partially explaining why metabolic yields are so highly affected by salinity. This work represents an important contribution to the elucidation of specific metabolic adaptations in compatible solute-accumulating halophilic bacteria.

Temperature- and salinity-decoupled overproduction of hydroxyectoine by Chromohalobacter salexigens.

Hydroxyectoine overproduction by the natural producer Chromohalobacter salexigens is presented in this study. Genetically engineered strains were constructed that at low salinity coexpressed, in a vector derived from a native plasmid, the ectoine (ectABC) and hydroxyectoine (ectD) genes under the control of the ectA promoter, in a temperature-independent manner. Hydroxyectoine production was further improved by increasing the copies of ectD and using a C. salexigens genetic background unable to synthesize ectoines.

Isoprenyl-thiourea and urea derivatives as new farnesyl diphosphate analogues: synthesis and in vitro antimicrobial and cytotoxic activities.

A series of new isoprenyl-thiourea and urea derivatives were synthesized by the reaction of alkyl or aryl isothiocyanate or isocyanate and primary amines. The structures of the compounds were established by (1)H NMR, (13)C NMR, MS, HRMS and elemental analysis. The new compounds were screened for in vitro antimicrobial activity against seven strains representing different types of gram-positive and gram-negative bacteria. More than a third of the synthesized compounds showed variable inhibition activities against the tested strains. Best antimicrobial activities were found for those thiourea analogues with 3-methyl-2-butenyl, isobutyl or isopentyl groups and aromatic rings possessing electron withdrawing substituents. The new compounds were also subjected to a preliminary screening for antitumoral activity. The presence of a highly lipophilic group and an electron withdrawing group in the aromatic rings enhanced anticancer activity of the synthesized compounds, showing in most cases more activity than that of the controls.

Role of trehalose in heat and desiccation tolerance in the soil bacterium Rhizobium etli.

BACKGROUND: The compatible solute trehalose is involved in the osmostress response of Rhizobium etli, the microsymbiont of Phaseolus vulgaris. In this work, we reconstructed trehalose metabolism in R. etli, and investigated its role in cellular adaptation and survival to heat and desiccation stress under free living conditions. RESULTS: Besides trehalose as major compatible solute, R. etli CE3 also accumulated glutamate and, if present in the medium, mannitol. Putative genes for trehalose synthesis (otsAB/treS/treZY), uptake (aglEFGK/thuEFGK) and degradation (thuAB/treC) were scattered among the chromosome and plasmids p42a, p42c, p42e, and p42f, and in some instances found redundant. Two copies of the otsA gene, encoding trehalose-6-P-synthase, were located in the chromosome (otsAch) and plasmid p42a (otsAa), and the latter seemed to be acquired by horizontal transfer. High temperature alone did not influence growth of R. etli, but a combination of high temperature and osmotic stress was more deleterious for growth than osmotic stress alone. Although high temperature induced some trehalose synthesis by R. etli, trehalose biosynthesis was mainly triggered by osmotic stress. However, an otsAch mutant, unable to synthesize trehalose in minimal medium, showed impaired growth at high temperature, suggesting that trehalose plays a role in thermoprotection of R. etli. Desiccation tolerance by R. etli wild type cells was dependent of high trehalose production by osmotic pre-conditioned cells. Cells of the mutant strain otsAch showed ca. 3-fold lower survival levels than the wild type strain after drying, and a null viability after 4 days storage. CONCLUSIONS: Our findings suggest a beneficial effect of osmotic stress in R. etli tolerance to desiccation, and an important role of trehalose on the response of R. etli to high temperature and desiccation stress.

A novel approach to postoperative bladder care in women after radical hysterectomy.

PURPOSE: Currently, controversy exists with regard to the duration of bladder drainage and choice of catheter used in women who undergo radical hysterectomy. In this manuscript, we propose a novel approach to improving postoperative bladder care in women who undergo radical hysterectomy. METHODS: This is a retrospective study of women who underwent Type 3 Piver radical hysterectomy in a gynaecological oncology centre in the United Kingdom from January 2009 to September 2011. We report the outcomes of removal of urinary catheter 48-72 h following radical hysterectomy. RESULTS: Over a 32-month period, 30 women underwent radical hysterectomy. 19 (63.3 %) women underwent surgery for treatment of cervical cancer, 5 (16.7 %) women for management of endometrial cancer, 6 (20 %) women for other conditions. One patient underwent partial cystectomy at the time of radical hysterectomy and was not included in the analysis. Of the 29 patients, only five (17.2 %) were found to have urinary residuals greater than 100 ml following the removal of the indwelling catheter on the second postoperative day and required recatheterisation. 82.8 % of the patients had the catheter removed within 48-72 h postoperatively. None of these patients required re-admission with urinary retention. CONCLUSION: Removal of urinary catheter on the second postoperative day following radical hysterectomy is feasible and not associated with increased morbidity. This approach may be particularly useful to complement the introduction of laparoscopic and robotic surgical approaches for surgical management of cervical cancer.

Role of trehalose in salinity and temperature tolerance in the model halophilic bacterium Chromohalobacter salexigens.

The disaccharide trehalose is considered as a universal stress molecule, protecting cells and biomolecules from injuries imposed by high osmolarity, heat, oxidation, desiccation and freezing. Chromohalobacter salexigens is a halophilic and extremely halotolerant γ-proteobacterium of the family Halomonadaceae. In this work, we have investigated the role of trehalose as a protectant against salinity, temperature and desiccation in C. salexigens. A mutant deficient in the trehalose-6-phosphate synthase gene (otsA::Ω) was not affected in its salt or heat tolerance, but double mutants ectoine- and trehalose-deficient, or hydroxyectoine-reduced and trehalose-deficient, displayed an osmo- and thermosensitive phenotype, respectively. This suggests a role of trehalose as a secondary solute involved in osmo- (at least at low salinity) and thermoprotection of C. salexigens. Interestingly, trehalose synthesis was osmoregulated at the transcriptional level, and thermoregulated at the post-transcriptional level, suggesting that C. salexigens cells need to be pre-conditioned by osmotic stress, in order to be able to quickly synthesize trehalose in response to heat stress. C. salexigens was more sensitive to desiccation than E. coli and desiccation tolerance was slightly improved when cells were grown at high temperature. Under these conditions, single mutants affected in the synthesis of trehalose or hydroxyectoine were more sensitive to desiccation than the wild-type strain. However, given the low survival rates of the wild type, the involvement of trehalose and hydroxyectoine in C. salexigens response to desiccation could not be firmly established.

Management of postmenopausal women with vaginal bleeding when the endometrium can not be visualized.

OBJECTIVE: To determine the risk of endometrial cancer when endometrial thickness is not visualized using ultrasonography. DESIGN: Cross-sectional study. SETTING: Gynecological oncology center in the United Kingdom. POPULATION: All postmenopausal women referred with vaginal bleeding. METHODS: All women were investigated using gray-scale transvaginal ultrasonography. Women were arbitrarily stratified into four groups according to the endometrial thickness measurement. Women with endometrial thickness that was not adequately visualized on ultrasonography were included in a separate group. MAIN OUTCOME MEASURES: Endometrial cancer diagnosis. RESULTS: Over a 50-month period, 4454 women were investigated for postmenopausal vaginal bleeding. A total of 259 (6%) of women were diagnosed with endometrial carcinoma. Endometrial thickness measured 5-9.9 mm in 1201 (27%), 10-14.9 mm in 468 (11%), 15-19.9 mm in 209 (5%), and equal to or greater than 20mm in 197 (4%) of women. In 174 (4%) of women, the endometrial thickness was not visualized on transvaginal ultrasonography. For women where the endometrial thickness was not adequately visualized, the final histology included benign endometrium (124), endometrial cancer (26), endometrial polyps (11), endometritis (7), and other pathology (7). The odds of endometrial cancer in women where the endometrial thickness was not visualized were found to be significantly higher than the odds of cancer for women with an endometrial thickness of 5-9.9 mm (OR = 5.23, 95%CI 3.10-8.85, p-value <0.0001). CONCLUSIONS: For women presenting with postmenopausal bleeding and where the endometrial thickness cannot be adequately visualized on ultrasonography, hysteroscopic evaluation is recommended.

Late presentation of metastatic smooth muscle neoplasm of the uterus with low malignant potential.

A 48-year-old woman underwent total abdominal hysterectomy with conservation of the ovaries and tubes. Histology showed a well-circumscribed smooth muscle tumor with foci of degeneration (including infarct-type necrosis) but no coagulative tumor cell necrosis and only mild focal cytological atypia. She presented, 24 years later with shortness of breath and abdominal distension and underwent bilateral salpingo-oophorectomy, appendectomy, omental biopsy and para-aortic lymph node sampling. Histology showed bilateral ovarian smooth muscle tumors with no coagulative tumor cell necrosis or significant cellular atypia. The cells were mitotically active. The tumors in both ovaries were most likely secondary to the previous uterine smooth muscle neoplasm. To our knowledge, this case is the first in the literature to describe a benign cellular leiomyoma that subsequently behaved as a smooth muscle tumor of uncertain malignant potential, which recurred 24 years after the initial diagnosis.

Postmenopausal vaginal bleeding in women using hormone replacement therapy.

OBJECTIVE: To estimate the risk of endometrial cancer in postmenopausal women presenting with vaginal bleeding using estrogen-progestogen hormone replacement therapy (HRT) regimens and to assess if the duration of HRT use has an effect on the risk of diagnosing endometrial cancer. STUDY DESIGN: Cross-sectional study of consecutive women presenting with postmenopausal vaginal bleeding at a gynaecological oncology centre in the UK. Main outcome measures Endometrial cancer diagnosis. RESULTS: Over a 62-month period, 4847 women were investigated for postmenopausal vaginal bleeding. The majority of women (4097, 84.5%) did not use any HRT preparation at the time of initial referral and 750 (15.5%) women were using combined HRT preparations. A total of 298 (6.1%) women were diagnosed with endometrial carcinoma. Women using HRT preparations were significantly less likely to be diagnosed with endometrial cancer compared with women not using HRT (adjusted odds ratio = 0.229, 95% CI 0.116-0.452; P < 0.0001). The longer duration of HRT use did increase the risk of diagnosing endometrial cancer in women presenting with postmenopausal vaginal bleeding, but this was not statistically significant. CONCLUSIONS: Postmenopausal women presenting with vaginal bleeding and using combined HRT preparations have significantly lower risk of being diagnosed with endometrial cancer when compared with women not using HRT.