Nucleophosmin 1 cooperates with the methyltransferase DOT1L to preserve peri-nucleolar heterochromatin organization by regulating H3K27me3 levels and DNA repeats expression

BACKGROUND

NPM1 is a phosphoprotein highly abundant in the nucleolus. However, additional nuclear functions have been attributed to NPM1, probably through interaction with other nuclear factors. DOT1L is one interaction partner of NPM1 that catalyzes methylation of histone H3 at lysine 79 (H3K79). DOT1L, playing functional roles in several biological processes, is known for its capability to organize and regulate chromatin. For example, DOT1L modulates DNA repeats expression within peri-nucleolar heterochromatin. NPM1 also affects peri-nucleolar heterochromatin spatial organization. However, it is unclear as of yet whether NPM1 and DOT1L functionally synergize to preserve nucleoli organization and genome stability, and generally, which molecular mechanisms would be involved.

RESULTS

We characterized the nuclear function of NPM1 on peri-nucleolar heterochromatin organization. We show that (i) monomeric NPM1 interacts preferentially with DOT1L in the nucleus; (ii) NPM1 acts in concert with DOT1L to maintain each other's protein homeostasis; (iii) NPM1 depletion results in H3K79me2 upregulation and differential enrichment at chromatin binding genes including Ezh2; (iv) NPM1 and DOT1L modulate DNA repeats expression and peri-nucleolar heterochromatin organization via epigenetic mechanisms dependent on H3K27me3.

CONCLUSIONS

Our findings give insights into molecular mechanisms employed by NPM1 and DOT1L to regulate heterochromatin activity and structural organization around the nucleoli and shed light on one aspect of the complex role of both proteins in chromatin dynamics.

ZBTB18 inhibits SREBP-dependent lipid synthesis by halting CTBPs and LSD1 activity in glioblastoma

Enhanced fatty acid synthesis is a hallmark of tumors, including glioblastoma. SREBF1/2 regulate the expression of enzymes involved in fatty acid and cholesterol synthesis. Yet, little is known about the precise mechanism regulating SREBP gene expression in glioblastoma. Here, we show that a novel interaction between the co-activator/co-repressor CTBP and the tumor suppressor ZBTB18 regulates the expression of SREBP genes. In line with our findings, metabolic assays and glucose tracing analysis confirm the reduction in several phospholipid species upon ZBTB18 expression. Our study identifies CTBP1/2 and LSD1 as co-activators of SREBP genes and indicates that the functional activity of the CTBP-LSD1 complex is altered by ZBTB18. ZBTB18 binding to the SREBP gene promoters is associated with reduced LSD1 demethylase activity of H3K4me2 and H3K9me2 marks. Concomitantly, the interaction between LSD1, CTBP, and ZNF217 is increased, suggesting that ZBTB18 promotes LSD1 scaffolding function. Our results outline a new epigenetic mechanism enrolled by ZBTB18 and its co-factors to regulate fatty acid synthesis that could be targeted to treat glioblastoma patients.

Statistical and agent-based modelling of the transmissibility of different SARS-CoV-2 variants in England and impact of different interventions

The English SARS-CoV-2 epidemic has been affected by the emergence of new viral variants such as B.1.177, Alpha and Delta, and changing restrictions. We used statistical models and the agent-based model Covasim, in June 2021, to estimate B.1.177 to be 20% more transmissible than the wild type, Alpha to be 50-80% more transmissible than B.1.177 and Delta to be 65-90% more transmissible than Alpha. Using these estimates in Covasim (calibrated 1 September 2020 to 20 June 2021), in June 2021, we found that due to the high transmissibility of Delta, resurgence in infections driven by the Delta variant would not be prevented, but would be strongly reduced by delaying the relaxation of restrictions by one month and with continued vaccination. This article is part of the theme issue 'Technical challenges of modelling real-life epidemics and examples of overcoming these'.

Statistical and agent-based modelling of the transmissibility of different SARS-CoV-2 variants in England and impact of different interventions

The English SARS-CoV-2 epidemic has been affected by the emergence of new viral variants such as B.1.177, Alpha and Delta, and changing restrictions. We used statistical models and the agent-based model Covasim, in June 2021, to estimate B.1.177 to be 20% more transmissible than the wild type, Alpha to be 50-80% more transmissible than B.1.177 and Delta to be 65-90% more transmissible than Alpha. Using these estimates in Covasim (calibrated 1 September 2020 to 20 June 2021), in June 2021, we found that due to the high transmissibility of Delta, resurgence in infections driven by the Delta variant would not be prevented, but would be strongly reduced by delaying the relaxation of restrictions by one month and with continued vaccination. This article is part of the theme issue 'Technical challenges of modelling real-life epidemics and examples of overcoming these'.

NF1 regulates mesenchymal glioblastoma plasticity and aggressiveness through the AP-1 transcription factor FOSL1

The molecular basis underlying glioblastoma (GBM) heterogeneity and plasticity is not fully understood. Using transcriptomic data of human patient-derived brain tumor stem cell lines (BTSCs), classified based on GBM-intrinsic signatures, we identify the AP-1 transcription factor FOSL1 as a key regulator of the mesenchymal (MES) subtype. We provide a mechanistic basis to the role of the neurofibromatosis type 1 gene (NF1), a negative regulator of the RAS/MAPK pathway, in GBM mesenchymal transformation through the modulation of FOSL1 expression. Depletion of FOSL1 in NF1-mutant human BTSCs and Kras-mutant mouse neural stem cells results in loss of the mesenchymal gene signature and reduction in stem cell properties and in vivo tumorigenic potential. Our data demonstrate that FOSL1 controls GBM plasticity and aggressiveness in response to NF1 alterations.

Effects of dietary microbial feed supplement on production efficacy in lactating dairy cows

This study evaluated the effects of a microbial feed supplement (MFS; Galaxis, Ascus Biosciences Inc.) comprising 2 native rumen microbes on performance parameters in mid-lactation dairy cows. Forty-six lactating primiparous and multiparous Holstein cows [629 ± 62 kg of body weight, mean ± standard deviation (SD); parity 1.64 ± 0.49; 119 ± 38 days in milk; 45.11 ± 3.81 and 52.73 ± 4.77 kg/d of milk yield for primiparous and multiparous, respectively] were enrolled in a study containing 3 experimental periods (P). During all periods, enrolled cows were fed the same base total mixed ration (TMR) ad libitum once daily. During P1 (7 d), baseline data were obtained for covariate analysis. At the beginning of P2 (60 d), cows were assigned to 1 of 2 dietary treatment groups in a randomized complete block design to balance for milk yield (MY), parity, and days in milk: (1) a control diet (CON; base TMR; n = 23), or (2) a control diet supplemented with 5 g/d of MFS (MFS; n = 23). Sample size was determined based on previous, unpublished results involving this MFS; a 3-kg difference between groups with a SD of 3.5 kg could be detected with sufficient power (0.81) using a total sample size of 46 cows. Treatment was top-dressed and hand-mixed into the top one-third of the TMR. During P3 (7 d), no treatment was administered, and all cows were fed the base TMR. When analyzing all cows in the data set, MFS had little to no effect on performance. However, modeling revealed that the fixed effect of covariate milk production level had a significant effect on the response of MY and ECM, and further investigation of the data revealed that treatment effectiveness in P2 correlated with milk production during P1. Cows were retrospectively categorized into 2 milk production groups (MPG) balanced for parity: MPG1 (i.e., <53 kg/d of ECM during P1; n = 34) or MPG2 (i.e., ≥53 kg/d of ECM during P1; n = 12). Energy-corrected milk was increased by 4.4% in MFS-administered MPG1 cows compared with CON cows during P2. Although there were no significant effects of MFS on production variables for MPG2 cows, MY tended to be decreased by 3.9% in MFS-administered cows compared with CON cows. Further investigation is needed to understand production level response differences and the effect of supplemented native rumen microbes on animal health and productivity.

DOT1L-mediated murine neuronal differentiation associates with H3K79me2 accumulation and preserves SOX2-enhancer accessibility

During neuronal differentiation, the transcriptional profile and the epigenetic context of neural committed cells is subject to significant rearrangements, but a systematic quantification of global histone modification changes is still missing. Here, we show that H3K79me2 increases and H3K27ac decreases globally during in-vitro neuronal differentiation of murine embryonic stem cells. DOT1L mediates all three degrees of methylation of H3K79 and its enzymatic activity is critical to modulate cellular differentiation and reprogramming. In this context, we find that inhibition of DOT1L in neural progenitor cells biases the transcriptional state towards neuronal differentiation, resulting in transcriptional upregulation of genes marked with H3K27me3 on the promoter region. We further show that DOT1L inhibition affects accessibility of SOX2-bound enhancers and impairs SOX2 binding in neural progenitors. Our work provides evidence that DOT1L activity gates differentiation of progenitors by allowing SOX2-dependent transcription of stemness programs.

THU0601 REFRACTORY ACUTE CORONARY SYNDROME AND CARDIOGENIC SHOCK AS ATYPICAL ONSET OF EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS

Background:

Eosinophilic Granulomatosis with Polyangiitis (EGPA) is an ANCA-associated vasculitis, characterized by eosinophilic infiltration in tissues, intravascular and extravascular granuloma formation. It is a rare disease, affecting between 0 and 4 per million population per year. The cardiac involvement occurs in 15-60% of EGPA patients (generally ANCA-negative); it is often insidious, underestimated and it has a poor prognosis. The disease usually shows a prodromal phase characterized by asthma and allergic manifestations.

Objectives:

We report the case of a young patient with acute coronary syndrome (ACS) complicated by cardiogenic shock as the first manifestation of EGPA.

Methods:

A 36 year old Indian male patient, with a previous history of asthma, rhinitis, Raynaud syndrome and allergy to ketoprofen, presented to the emergency department with a complaint of chest pain and dyspnea. Cardiac troponin was elevated and he was admitted to intensive care unit with a diagnosis of ACS. The patient conditions rapidly deteriorated due to acute cardiogenic shock and an urgent coronary angiogram was performed. An occlusion of the left main coronary artery was treated with angioplasty and two drug-eluting stents. Echocardiography showed severe left ventricular dysfunction requiring inotropic and intra-aortic balloon pump support. A mild dermatitis after salicylic acid administration resolved with intravenous hydrocortisone 1 g. The thrombophilia screening was negative, as well as cardiovascular risk factors. Over the next days, the clinical conditions rapidly improved with recovery of normal ventricular function on discharge. However, two weeks later he was readmitted with recurrent mandibular and chest pain. Troponin levels were elevated and fluctuated, suggesting recurrent ischemic events. Repeated ECG during angina crisis showed ischemic alterations in different coronary territories. The coronary angiogram detected coronary vasospasm of the circumflex artery, reversible after nitroglycerin (Figure 1). Nitroglycerin and calcium channel blockers were initiated, but did not resolve the vasospastic angina crisis, occurring daily. Laboratory tests revealed eosinophilia (4390 cells/mcl), increased C reactive protein (9.4 mg/l) and positive antinuclear antibodies (1:320). The other serological and immunological tests were negative, including MPO-ANCA and PR3-ANCA. An abdomen and chest CT scan was negative.

Figure 1.

Coronary angiogram showing coronary vasospasm in the left circumflex artery (panel A, yellow arrow), reversible after nytroglicerin infusion (panel B, yellow arrow)

Results:

The eosinophilia and the history of asthma rose the suspect of EGPA vasculitis. The patient was treated with intravenous methylprednisolone 250 mg once daily for 3 days, followed by oral prednisone 1 mg/kg/day, with rapid and complete resolution of the recurrent angina episodes. Intravenous cyclophosphamide 10 mg/kg was administered every 2 weeks for 2 times, then 12 mg/kg every 4 weeks. Oral corticosteroid was tapered, with the persistence of a complete remission of the symptoms, after 2 months of immunosuppressive therapy.

Conclusion:

Coronary involvement in EGPA can mimic atherosclerotic artery disease and can be life threatening, if not promptly recognized. An accurate medical history and complete serological and immunological tests are crucial to detect an atypical onset of EGPA, prompting early immunosuppressive therapy which is pivotal for the patient survival.

References:

[1]MR Hazebroek et al. Prevalence and Prognostic Relevance of Cardiac Involvement in ANCA-associated Vasculitis: Eosinophilic Granulomatosis With Polyangiitis and Granulomatosis With Polyangiitis. Int J Cardiol 2015, 199: 170-9.

Disclosure of Interests:

None declared

DOI: 10.1136/annrheumdis-2020-eular.6482

A comparative study of combined intravenous and topical administration of tranexamic acid with topical tranexamic acid alone for blood loss reduction after primary uncemented total hip arthroplasty

The aim of the present study was to evaluate the efficacy of topical versus combined (intravenous + topical) tranexamic acid (TXA) to reduce perioperative blood loss after uncemented primary total hip arthroplasty (THA). Seventy-five patients were randomized in three comparable experimental groups: 1) topical TXA (3 g in 50 ml of saline solution); 2) intravenous + topical TXA (3 g topical + 2 g in 100 ml of saline solution intravenously); 3) controls. Pre- and post-operative hemoglobin (Hb) levels and hematocrit (Hct) values along with the rate of blood transfusion in the 3 groups were compared. The intravenous + topical TXA group demonstrated higher Hb levels and Hct values at postoperative day one (Hb = p <0.05, Hct = p <0.001), postoperative day three (Hb = p <0.05, Hct = p <0.001), and discharge (Hct = p <0.01) compared to the control group. The intravenous + topical group had a lower transfusion rate compared to the control group (0% vs 20%, p = 0.014). With the numbers available, no difference in postoperative Hb level and transfusion rate emerged between topical TXA and control group.

Dynamic changes in H1 subtype composition during epigenetic reprogramming

In mammals, the histone H1 family includes five somatic replication-dependent (H1.1–H1.5) and two replication-independent (H1.10 and H1.0) subtypes. Izzo et al. analyze the contributions of all somatic H1 subtypes to the chromatin landscape during reprogramming in preimplantation embryo and primordial germ cell development.

In mammals, histone H1 consists of a family of related proteins, including five replication-dependent (H1.1–H1.5) and two replication-independent (H1.10 and H1.0) subtypes, all expressed in somatic cells. To systematically study the expression and function of H1 subtypes, we generated knockin mouse lines in which endogenous H1 subtypes are tagged. We focused on key developmental periods when epigenetic reprogramming occurs: early mouse embryos and primordial germ cell development. We found that dynamic changes in H1 subtype expression and localization are tightly linked with chromatin remodeling and might be crucial for transitions in chromatin structure during reprogramming. Although all somatic H1 subtypes are present in the blastocyst, each stage of preimplantation development is characterized by a different combination of H1 subtypes. Similarly, the relative abundance of somatic H1 subtypes can distinguish male and female chromatin upon sex differentiation in developing germ cells. Overall, our data provide new insights into the chromatin changes underlying epigenetic reprogramming. We suggest that distinct H1 subtypes may mediate the extensive chromatin remodeling occurring during epigenetic reprogramming and that they may be key players in the acquisition of cellular totipotency and the establishment of specific cellular states.

Giant endometrial cyst of the liver: a case report and review of the literature

Endometriosis is a benign condition described as the presence of endometrial- like tissue found outside the uterine cavity. Hepatic endometriosis is one of the rarest localization of extrapelvic endometriosis, only 22 cases have been reported in the literature. The preoperative diagnosis of hepatic endometriosis is rather difficult because in about the half of the patient affected they had no history of endometriosis. Moreover radiological images reveal no characteristic findings for hepatic endometriosis. It is often described as cystic mass with or without solid component, difficult to distinguish from hepatic abscess, hematoma, cystoadenoma or malignant neoplasia. We report a case of a 27-year-old female with a large cystic mass involving the left lobe of the liver. The patient underwent laparoscopic exploration and converted to laparotomy for resection of giant hepatic endometriosis.

H1 gets the genome in shape

By performing high-throughput chromosome conformation capture analyses in embryonic stem cells depleted of the linker histone H1, Geeven and colleagues have uncovered exciting new evidence concerning a role for this histone in modulating three-dimensional genome architecture and chromatin organization.

Please see link to Research article: http://www.genomebiology.com/2015/16/1/289

Design, development and characterization of a modular end effector for MIS procedures

The Minimally Invasive Surgery (MIS) paradigm is well established in modern surgical procedures. Although MIS is successful from the patient's viewpoint, the use of rigid instruments inserted through small skin incisions leads to dexterity constraints and loss of degree of motion. Robotics has been introduced as support for augmenting dexterity during interventions, restoring hand-eye coordination and providing tools with enhanced degrees of motion. However, surgical robots have high costs and large footprint, pushing the research towards the development of modular robots to be used in Naturally Orifice Trans-luminal Endoscopic Surgery (NOTES) procedures. The main need of having simple and cheap tools able to be interchanged during the surgical procedure became crucial. In this paper an innovative modular end-effector based on a compliant soft actuation system able to provide up to 5.78 N gripping forces is presented.

Renovascular anatomic variants at CT angiography

AIM

The aim of this paper was to assess the origin and course variations of vessels forming the renal vascular pedicle.

METHODS

The IRB approved study retrospectively evaluated 921 consecutive patients (503 females, 418 males; mean age, 54 years), who underwent multidetector computed tomographic (MDCT) of the abdomen for various purposes at our Department of Radiology, between January 2012 and December 2013. Multiplanar and volumetric reformations were performed in all cases. For each set of images, the locations of renal artery origins and renal venous drainage, such as all renal vessels variations, including division variations and presence of extrarenal vessels, were investigated.

RESULTS

The tract of the aorta between the upper margin of L1 and the lower margin of L2 originated 96% of main renal arteries and 72% of extra renal arteries. The most common location for renal artery origin was the L1- L2 intervertebral disc level. Sixty-nine percent of patients showed a single renal artery, with multiple arteries in 31%, bilateral multiple arteries in 11%, and early division in 6% of cases. Additional renal arteries were detected on the right side in 5% and on the left side in 12% of cases. With regard to the venous drainage, 89.8% of patients showed a single renal vein, with multiple vein in 10.2%, while 23.8% showed a retro-aortic course of the renal vein.

CONCLUSION

Renal arteries and veins variations of origin and course are not infrequent. Extrarenal vessels may compromise renal surgery. The awareness of any possible renovascular anomaly is crucial in case of a non-invasive diagnostic search for renal artery stenosis, and when renal surgery related to renal arteries is performed, such as in case of interventional radiological procedures, urological and vascular operations, and renal transplantation.

The role of linker histone H1 modifications in the regulation of gene expression and chromatin dynamics

BACKGROUND

Linker histone H1 is a structural component of chromatin. It exists as a family of related proteins known as variants and/or subtypes. H1.1, H1.2, H1.3, H1.4 and H1.5 are present in most somatic cells, whereas other subtypes are mainly expressed in more specialized cells.

SCOPE OF REVIEW

H1 subtypes have been shown to have unique functions in chromatin structure and dynamics. This can occur at least in part via specific post-translational modifications of distinct H1 subtypes. However, while core histone modifications have been extensively studied, our knowledge of H1 modifications and their molecular functions has remained for a long time limited to phosphorylation. In this review we discuss the current state of knowledge of linker histone H1 modifications and where possible highlight functional differences in the modifications of distinct H1 subtypes.

MAJOR CONCLUSIONS AND GENERAL SIGNIFICANCE

H1 histones are intensely post-translationally modified. These modifications are located in the N- and C-terminal tails as well as within the globular domain. Recently, advanced mass spectrometrical analysis revealed a large number of novel histone H1 subtype specific modification sites and types. H1 modifications include phosphorylation, acetylation, methylation, ubiquitination, and ADP ribosylation. They are involved in the regulation of all aspects of linker histone functions, however their mechanism of action is often only poorly understood. Therefore systematic functional characterization of H1 modifications will be necessary in order to better understand their role in gene regulation as well as in higher-order chromatin structure and dynamics.

Recombinant adenovirus delivery of calreticulin-ESAT-6 produces an antigen-specific immune response but no protection against a Mycobacterium tuberculosis challenge

Bacillus Calmette-Guerin (BCG) has failed to efficaciously control the worldwide spread of the disease. New vaccine development targets virulence antigens of Mycobacterium tuberculosis that are deleted in Mycobacterium bovis BCG. Immunization with ESAT-6 and CFP10 provides protection against M. tuberculosis in a murine infection model. Further, previous studies have shown that calreticulin increases the cell-mediated immune responses to antigens. Therefore, to test whether calreticulin enhances the immune response against M. tuberculosis antigens, we fused ESAT-6 to calreticulin and constructed a recombinant replication-deficient adenovirus to express the resulting fusion protein (AdCRT-ESAT-6). The adjuvant effect of calreticulin was assayed by measuring cytokine responses specific to ESAT-6. Recombinant adenovirus expressing the fusion protein produced higher levels of interferon-γ and tumour necrosis factor-α in response to ESAT-6. This immune response was not improved by the addition of CFP-10 to the CRT-ESAT-6 fusion protein (AdCRT-ESAT-6-CFP10). Mice immunized with these recombinant adenoviruses did not decrease the mycobacterial burden after low-dose aerosol infection with M. tuberculosis. We conclude that calreticulin can be used as an adjuvant to enhance the immune response against mycobacterial antigens, but it is not enough to protect against tuberculosis.

A dual role of linker histone H1.4 Lys 34 acetylation in transcriptional activation

The linker histone H1 is a key player in chromatin organization, yet our understanding of the regulation of H1 functions by post-translational modifications is very limited. We provide here the first functional characterization of H1 acetylation. We show that H1.4K34 acetylation (H1.4K34ac) is mediated by GCN5 and is preferentially enriched at promoters of active genes, where it stimulates transcription by increasing H1 mobility and recruiting a general transcription factor. H1.4K34ac is dynamic during spermatogenesis and marks undifferentiated cells such as induced pluripotent stem (iPS) cells and testicular germ cell tumors. We propose a model for H1.4K34ac as a novel regulator of chromatin function with a dual role in transcriptional activation.

40 Mb duplication in chromosome band 5p13.1p15.33 with 800 kb terminal deletion in a foetus with mild phenotypic features

Large duplication of the short arm of chromosome 5 is a rare condition normally associated to severe phenotype anomalies including heart and brain malformations. We report a prenatal case of a large 5p duplication with sub-telomeric deletion in a foetus with very mild phenotypic abnormalities. Foetal ultrasonographic examination at 22 weeks of gestation showed short femur, clubfeet, pielectasy, and facial dysmorphisms. Chromosome investigations revealed an inverted duplication of the short arm of chromosome 5 from 5p13.1 to 5p15.33 and a 800 kb deletion at 5pter. The absence of severe anomalies such as cardiac and cerebral defects, observed so far in all large 5p duplications, and the comparison to previous cases described both in literature and in DECIPHER database suggest that the critical region for the severe phenotype in 5p duplication syndrome might be smaller than that previously described, excluding half of the 5p13 band. This might help in prenatal genetic counselling.

Methylation of H2AR29 is a novel repressive PRMT6 target

BACKGROUND

Covalent histone modifications are central to all DNA-dependent processes. Modifications of histones H3 and H4 are becoming well characterised, but knowledge of how H2A modifications regulate chromatin dynamics and gene expression is still very limited.

RESULTS

To understand the function of H2A modifications, we performed a systematic analysis of the histone H2A methylation status. We identified and functionally characterised two new methylation sites in H2A: R11 (H2AR11) and R29 (H2AR29). Using an unbiased biochemical approach in combination with candidate assays we showed that protein arginine methyltransferase (PRMT) 1 and PRMT6 are unique in their ability to catalyse these modifications. Importantly we found that H2AR29me2 is specifically enriched at genes repressed by PRMT6, implicating H2AR29me2 in transcriptional repression.

CONCLUSIONS

Our data establishes R11 and R29 as new arginine methylation sites in H2A. We identified the specific modifying enzymes involved, and uncovered a novel functional role of H2AR29me2 in gene silencing in vivo. Thus this work reveals novel insights into the function of H2A methylation and in the mechanisms of PRMT6-mediated transcriptional repression.

Chatting histone modifications in mammals

Eukaryotic chromatin can be highly dynamic and can continuously exchange between an open transcriptionally active conformation and a compacted silenced one. Post-translational modifications of histones have a pivotal role in regulating chromatin states, thus influencing all chromatin dependent processes. Methylation is currently one of the best characterized histone modification and occurs on arginine and lysine residues. Histone methylation can regulate other modifications (e.g. acetylation, phosphorylation and ubiquitination) in order to define a precise functional chromatin environment. In this review we focus on histone methylation and demethylation, as well as on the enzymes responsible for setting these marks. In particular we are describing novel concepts on the interdependence of histone modifications marks and discussing the molecular mechanisms governing this cross-talks.

Histone H2A C-terminus regulates chromatin dynamics, remodeling, and histone H1 binding

The tails of histone proteins are central players for all chromatin-mediated processes. Whereas the N-terminal histone tails have been studied extensively, little is known about the function of the H2A C-terminus. Here, we show that the H2A C-terminal tail plays a pivotal role in regulating chromatin structure and dynamics. We find that cells expressing C-terminally truncated H2A show increased stress sensitivity. Moreover, both the complete and the partial deletion of the tail result in increased histone exchange kinetics and nucleosome mobility in vivo and in vitro. Importantly, our experiments reveal that the H2A C-terminus is required for efficient nucleosome translocation by ISWI-type chromatin remodelers and acts as a novel recognition module for linker histone H1. Thus, we suggest that the H2A C-terminal tail has a bipartite function: stabilisation of the nucleosomal core particle, as well as mediation of the protein interactions that control chromatin dynamics and conformation.

Histones are the main protein components of chromatin. The N-terminal tails of histones stick out from the nucleosomes, the building blocks of chromatin, and are involved in the regulation of all DNA–dependent processes. Only Histone H2A has an additional C-terminal tail and currently very little is known about the function of this tail. The H2A C-terminus protrudes from the nucleosome and is located where the DNA enters and leaves the nucleosome. We show here that it can interact with the linker histone H1 that is important for higher order chromatin structure. We also find that this tail is involved in regulating nucleosome dynamics and mobility of H2A itself. The C-terminal H2A tail has also an important function in regulating the activity of chromatin remodelers, enzymes that can reposition nucleosomes. Furthermore we find that cells expressing C-terminally truncated H2A are more sensitive to stress, demonstrating that this tail is important for cellular homeostasis. Together our results reflect a key function of the H2A C-terminus in chromatin biology.

Rehabilitative treatment in peripheral artery disease: protocol application and follow-up

AIM

Peripheral arterial disease (PAD) is a chronic figure suitable to be treated at the II stage to prevent the extreme developments both of the critical limb ischemia and the amputation, as well. The aim of this study was to establish a rehabilitation program (pharmacological and physical) focused not only on the improvement of the flow but also on the metabolic rebalancing in the claudicant limb.

METHODS

The study enrolled 222 patients, (125 non-diabetics and 97 diabetics): 54 II A and 168 II B stage; 172 patients (131 II B and 41 II A; 104 non-diabetics and 68 diabetics) were submitted to iv. L-propionil carnytine (Lpc) and physical training on treadmill or exercise bike and 50 patients to iv. therapy alone. Instrumental (Rheoscreen, Oximetry, ABI, walking distance measurement) and clinical checks (questionnaire - Appendix 1) were performed at days: T0, T45,T 90,T180, T230 and during the follow up stated at T 90,T180,T360 from T 230 (end of DH).

RESULTS

A significant increasing of the walking distance has been reached in the group undergoing the rehabilitation program. Treadmill: non-diabetics +261.48% at 0% and +122.53% at slope 10% (T230) further increasing to +502.31% at 0% and +289.42% at slope 10% (T360); diabetics: + 158.49% at T0 and + 98.26% at slope 10% (T230) further increased to +287.74% at 0% and +197.39% at 10% (T360) in comparison with the group which had only iv. Lpc : non-diabetics +141.63% at 0% and +104.08% at slope 10% (T230) further increased to +202.064% at 0% and +155.10% at slope 10% (T360); diabetics: +109.124% at T0 and +100% at slop 10% (T230) further increased to +171.08% at 0% and +140% at 10% (T360) . Exercise bike: non-diabetics: +170.27% at T230 in comparison T0 increased to +305.4% at T360; diabetics: +166.66 at T230 reaching +288.88% at T 360.

CONCLUSION

Our rehabilitative program gives not only good results at the end of the treatment but mainly stable, with the chance to reach further improving of both walking distance and quality of life, particularly in those patients which observe constantly the physical training.

Systematic quality control for management of ST elevation acute myocardial infarction in setting of local network

AIM

Adherence to evidence based guidelines, assessed by measuring key indicators, allows to detect, evaluate and improve quality of care. Since 2004 in Carlo Poma Hospital, following the introduction of a network for ST-elevation myocardial infarction (STEMI) management, the authors carried out a clinical database in order to measure quality of care in STEMI patients.

MATERIALS AND METHODS

A real time upgradable database was developed, to assess clinical practice in myocardial infarction management. The authors evaluated prevalence and control of risk factors, pharmacological therapies and interventional procedures, pathways and delays to care.

RESULTS

From 1 February 2004 to 31 January 2008, 1,714 consecutive patients with myocardial infarction were admitted in the Intensive Care Unit (ICU). Primary percutaneous coronary intervention (PCI) was performed in 85% of STEMI patients. Door to balloon time was greater than 90 min in only 17% of patients, of whom 88% coming from emergency department and 12% transferred by 118.

CONCLUSION

In the authors' experience quality indicators proved useful in the management of myocardial infarction. Implementation of 118 and improvement of pre-hospital diagnosis in setting of local network can reduce time to treatment.

Histone H1 variant-specific lysine methylation by G9a/KMT1C and Glp1/KMT1D

Background

The linker histone H1 has a key role in establishing and maintaining higher order chromatin structure and in regulating gene expression. Mammals express up to 11 different H1 variants, with H1.2 and H1.4 being the predominant ones in most somatic cells. Like core histones, H1 has high levels of covalent modifications; however, the full set of modifications and their biological role are largely unknown.

Results

In this study, we used a candidate screen to identify enzymes that methylate H1 and to map their corresponding methylation sites. We found that the histone lysine methyltransferases G9a/KMT1C and Glp1/KMT1D methylate H1.2 in vitro and in vivo, and we mapped this novel site to lysine 187 (H1.2K187) in the C-terminus of H1. This H1.2K187 methylation is variant-specific. The main target for methylation by G9a in H1.2, H1.3, H1.5 and H1.0 is in the C-terminus, whereas H1.4 is preferentially methylated at K26 (H1.4K26me) in the N-terminus. We found that the readout of these marks is different; H1.4K26me can recruit HP1, but H1.2K187me cannot. Likewise, JMJD2D/KDM4 only reverses H1.4K26 methylation, clearly distinguishing these two methylation sites. Further, in contrast to C-terminal H1 phosphorylation, H1.2K187 methylation level is steady throughout the cell cycle.

Conclusions

We have characterised a novel methylation site in the C-terminus of H1 that is the target of G9a/Glp1 both in vitro and in vivo. To our knowledge, this is the first demonstration of variant-specific histone methylation by the same methyltransferases, but with differing downstream readers, thereby supporting the hypothesis of H1 variants having specific functions.

Changes in ectomycorrhizal community structure on two containerized oak hosts across an experimental hydrologic gradient

Shifts in ectomycorrhizal (ECM) community structure were examined across an experimental hydrologic gradient on containerized seedlings of two oak species, Quercus montana and Quercus palustris, inoculated from a homogenate of roots from mature oak trees. At the end of one growing season, seedlings were harvested, roots were sorted by morphotype, and proportional colonization of each type was determined. DNA was subsequently extracted from individual root tips for polymerase chain reaction, restriction fragment length polymorphism, and rDNA sequencing of the ITS1/5.8S/ITS2 region to determine identities of fungal morphotypes. Twelve distinct molecular types were identified. Analysis of similarity showed that ECM fungal assemblages shifted significantly in composition across the soil moisture gradient. Taxa within the genus Tuber and the family Thelephoraceae were largely responsible for the changes in fungal assemblages. There were also significant differences in ECM community assemblages between the two oak host species. These results demonstrate that the structure of ECM fungal communities depends on both the abiotic and biotic environments and can shift with changes in soil moisture as well as host plant, even within the same genus.

[Mortality triplicates in acute myocardial infarction patients affected by chronic renal failure]

In order to calculate the cardiovascular risk in patients with chronic renal failure (CRF), we retrospectively analyzed 1482 acute myocardial infarctions (AMIs) treated in the ICU at C. Poma General Hospital, Mantua, Italy, from 1 December 2004 to 31 July 2007. Of these patients, 133 suffered from CRF at hospital admission (eGFR <40 mL/min/1.73 m2 body surface and/or serum creatinine >2 mg/dL). During hospitalization for AMI, the CRF-affected patients showed a 2.7 times higher relative risk of mortality than patients without CRF (Yates chi square 14.46; p = 0.0001432). The evaluated comorbidities (hypertension, type 2 diabetes, supra-aortic vascular stenosis >70%, previous PTCA, COPD, previous AMI, previous coronary artery bypass and chronic obliterative peripheral arteriopathy) increased the relative risk of death 1.2- to 3.76-fold in those affected. In accord with recent evidence in the international literature, our results point to the importance of early assessment of CRF for the prognosis of patients with AMI.

The histone H1 family: specific members, specific functions?

The linker histone H1 binds to the DNA entering and exiting the nucleosomal core particle and has an important role in establishing and maintaining higher order chromatin structures. H1 forms a complex family of related proteins with distinct species, tissue and developmental specificity. In higher eukaryotes all H1 variants have the same general structure, consisting of a central conserved globular domain and less conserved N-terminal and C-terminal tails. These tails are moderately conserved among species, but differ among variants, suggesting a specific function for each H1 variant. Due to compensatory mechanisms and to the lack of proper tools, it has been very difficult to study the biological role of individual variants in chromatin-mediated processes. Our knowledge about H1 variants is indeed limited, and in vitro and in vivo observations have often been contradictory. Therefore, H1 variants were considered to be functionally redundant. However, recent knockout studies and biochemical analyses in different organisms have revealed exciting new insights into the specificity and mechanisms of actions of the H1 family members. Here, we collect and compare the available literature about H1 variants and discuss possible specific roles that challenge the concept of H1 being a mere structural component of chromatin and a general repressor of transcription.

Evaluation of the efficacy of propionyl-L-carnitine versus pulsed muscular compressions in diabetic and non-diabetic patients affected by obliterating arteriopathy Leriche stage II

AIM

The effectiveness of propionyl-L-carnitine (PLC) monotherapy regimen alone or in association with pulsed muscular compression was compared to the physical therapy by itself against obliterant arteriopathy Leriche Fontaine stage II. PLC is involved in cellular metabolism and is transformed into two active substances, free L-carnitine and propionyl-coenzyme A in the mitochondria, which take part in fatty acid transfer and in the citric acid cycle, respectively.

METHODS

Forty-two patients with arterial disease were selected (22 males and 20 females; mean age: 62+/-8 years; 21 type 2 diabetic [DB] and 21 non-DB [NDB]). At enrollment all patients completed a symptoms questionnaire enabling both clinical and social evaluation of the impact of the arteriopathy on the quality of life. Then, patients had: routine blood samples, echo duplex scan; evaluation of the ankle/arm (Winsor) index; impedance plethysmography (Rheoscreen) to measure the crest time (CT), index of the pathological changes due to the sclerosis on the vascular wall, and measurement of walking distance by means of treadmill test. Patients were randomized in three groups, each of them composed by 14 patients (7 DB and 7 NDB): the first group was submitted to infusional PLC therapy at a dosage of 4 fl (total: 1,200 mg PLC) in 250 cc of physiological solution for 5 days a week for 4 weeks; the second group was treated with PLC in association with pulsed muscular compression therapy by Vascupump (5 sessions a week for 4 weeks); the third group was submitted only to Vascupump.

RESULTS

The efficacy of both PLC and Vascupump in the treatment of the peripheral vasculopathies was confirmed. From a subjective point of view, patients referred benefits both in clinical terms, i.e. increased walking distance (average increaseaegroup I: DB 102%, NDB 118%; group II: DB 94%, NDB 193%; group III: DB 33%, NDB 67%) and of decreased intensity of the calf pain from the quality of life questionnaire (21.5 to 10.7). The instrumental parameters showed a trend towards normality, i.e decrease in CT and an increase of the Winsor index, indicators of increased peripheral blood circulation.

CONCLUSION

Combined pharmaco- and physical therapy was most efficient treatment regime and best results were seen in NDB compared to the DB patients.

[Evaluation of radon levels in bank buildings: results of a survey on a major Italian banking group]

Radon, the second cause of lung cancer after smoking, is a natural, radioactive gas, which originates from the soil and pollutes indoor air, especially in closed or underground spaces. Italian legislation recommends an action level of 500 Bq/m3 per year for occupational exposure in underground premises.

OBJECTIVES

Since banks usually use various underground premises (archives, safe-deposit room), a study was made of the radon levels on such premises with the aim of identifying useful monitoring strategies.

METHODS

134 branches of a major Italian banking group were examined using 1817 nuclear track dosimeters at ground level and underground level premises. The branches were located in 7 Italian regions in the north (Piedmont, Lombardy, Veneto), centre (Lazio) and south (Campania, Apulia, Sicily). Information on measurement points was recorded in a technical sheet and statistical analysis was carried out.

RESULTS

Annual underground measurements gave an average concentration of 157 Bq/m3, with 5.1% for 400 < C < 500 Bq/m3 and 2.9%for C > 500 Bq/m3. Seasonal variability was reflected in a significant decrease in concentrations between winter and spring (delta(mean)% = -47.3%) and good stability between autumn and winter (delta(mean)% = 3%); moreover quarterly concentrations account for 85% of the variability of the corresponding annual level. A multiple linear regression model (R2 = 0.33) indicated geographic location as the principal factor in radon accumulation, followed by underground level, humidity, use, lack of windows, heating and natural ventilation, and direct contact of at least one wall with ground rock; whereas the safe-deposit room structure seems to protect from radon accumulation. Moreover, the ground level measurement results were significantly associated with the corresponding underground average concentrations (p < 0.001).

CONCLUSIONS

The results could be a useful tool in planning a monitoring strategy for assessment of bank worker exposure, especially for banking groups with a large number of branches.

Structure-function analysis of the RNA helicase maleless

Loss of function of the RNA helicase maleless (MLE) in Drosophila melanogaster leads to male-specific lethality due to a failure of X chromosome dosage compensation. MLE is presumably involved in incorporating the non-coding roX RNA into the dosage compensation complex (DCC), which is an essential but poorly understood requirement for faithful targeting of the complex to the X chromosome. Sequence comparison predicts several RNA-binding domains in MLE but their properties have not been experimentally verified. We evaluated the RNA-binding characteristics of these conserved motifs and their contributions to RNA-stimulated ATPase activity, to helicase activity, as well as to the targeting of MLE to the nucleus and to the X chromosome territory. We find that RB2 is the dominant, conditional RNA-binding module, which is indispensable for ATPase and helicase activity whereas the N-terminal RB1 motif does not bind RNA, but is involved in targeting MLE to the X chromosome. The C-terminal domain containing a glycine-rich heptad repeat adds potential dimerization and RNA-binding surfaces which are not required for helicase activity.

Automated quality control in computed radiography

PURPOSE

The purpose of this paper is to describe the automation of quality control procedures on photo-stimulable imaging plates by means of an image-processing tool providing automatic reading of the images and automatic calculation of the quality parameters monitored.

MATERIALS AND METHODS

Quality-control procedures were performed according to the main available guidelines. The quality assurance programme was applied to several Kodak and Philips devices in four radiological departments. The automatic image-processing tool was developed using public domain software (Java-based ImageJ software) and contains both reading and computation procedures.

RESULTS

The quality checks and algorithms described were successfully applied, proving useful for identification of defective plates and for implementation of the quality assurance programme. The use of automation allowed significant savings in the time required for quality checks.

CONCLUSIONS

Completely automated image reading allows substantial economic and human resources savings, as it eliminates much of the transfer, reproduction, processing and filing procedures.

Pleiotropic role of VEGF-A in regulating fetal pulmonary mesenchymal cell turnover

Tight regulation of VEGF-A production and signaling is important for the maintenance of lung development and homeostasis. VEGF null mice have provided little insight into the role of VEGF during the later stages of lung morphogenesis. Therefore, we examined the in vitro effects of autocrine and paracrine VEGF-A production and the inhibition of VEGF-A signaling on a Flk-1-negative subset of fetal pulmonary mesenchymal cells (pMC). We hypothesized that VEGF-A receptor signaling regulates turnover of fetal lung mesenchyme in a cell cycle-dependent manner. VEGF receptor blockade with SU-5416 caused cell spreading and decreased proliferation and bcl-2 localization. Nuclear expression of the cell cycle inhibitory protein, p21, was increased with SU-5416 treatment, and p27 was absent. Autocrine VEGF production by pMC resulted in proliferation and p21/p27-dependent contact inhibition. In contrast, exogenous VEGF-A increased cell progression through the cell cycle. Selective activation of Flt by placental growth factor demonstrated the importance of this receptor/kinase in the VEGF-A responsiveness of pMC. The expression and localization of the survival factor bcl-2 was dependent on VEGF. These results provide evidence that VEGF-A plays a critical role in the regulation of fetal pulmonary mesenchymal proliferation, survival, and the subsequent development of normal lung architecture through bcl-2 and p21/p27-dependent cell cycle control.

The MRG domain mediates the functional integration of MSL3 into the dosage compensation complex

The male-specific-lethal (MSL) proteins in Drosophila melanogaster serve to adjust gene expression levels in male flies containing a single X chromosome to equal those in females with a double dose of X-linked genes. Together with noncoding roX RNA, MSL proteins form the "dosage compensation complex" (DCC), which interacts selectively with the X chromosome to restrict the transcription-activating histone H4 acetyltransferase MOF (males-absent-on-the-first) to that chromosome. We showed previously that MSL3 is essential for the activation of MOF's nucleosomal histone acetyltransferase activity within an MSL1-MOF complex. By characterizing the MSL3 domain structure and its associated functions, we now found that the nucleic acid binding determinants reside in the N terminus of MSL3, well separable from the C-terminal MRG signatures that form an integrated domain required for MSL1 interaction. Interaction with MSL1 mediates the activation of MOF in vitro and the targeting of MSL3 to the X-chromosomal territory in vivo. An N-terminal truncation that lacks the chromo-related domain and all nucleic acid binding activity is able to trigger de novo assembly of the DCC and establishment of an acetylated X-chromosome territory.

[Coronary disease: early intervention saves lives. Treatment of acute myocardial infarction in Mantova: results of thirty months of work after the implementation of a province network]

BACKGROUND

Since June 2001, in the province of Mantova, we have undertaken a program for the management of acute myocardial infarction based on the early assessment of patient risk profiles, concerning telematic connections among care centers and on the optimization of in-hospital and out of hospital critical pathways for access to care.

MATERIALS AND METHODS

Our network provides connections among the following centers: advanced life support ambulances, seven hospitals, three coronary care units, one cath lab on call 24 h a day for primary angioplasty, and one thoracic surgery division. This program, through its strong telematic platform, allows the early assessment of myocardial infarction and provides primary angioplasty to all high-risk patients, as fibrinolytic treatment is reserved only for low-risk patients admitted in peripheral hospitals.

RESULTS

Two hundred and eighty patients with acute myocardial infarction were treated with angioplasty; 224 patients (80%) underwent primary angioplasty, 36 patients (13%) facilitated angioplasty and 20 patients (7%) rescue angioplasty. One hundred and thirty-two patients (47%) were first admitted to Mantova Hospital; 78 patients (28%) were referred to Mantova from peripheral hospitals and 70 patients (25%) were directly transported to the cath lab by advanced life support ambulances. Procedural success was obtained in 98% of patients, with 0.4% intraprocedural mortality. In-hospital mortality was 5.7%, while mortality in cardiogenic shock patients was 36%. The recurrence of acute myocardial infarction occurred in 1% of patients and major bleeding occurred in 2.2% of patients. One patient with cardiogenic shock died during transport. Mean door to balloon time was 67 min with a 42% reduction in the 3rd recruitment period.

CONCLUSIONS

This program, developed in the setting of a provincial network for the management of acute myocardial infarction, provided primary angioplasty to all high-risk patients, with a high procedural success rate. Within a few months, time to treatment was minimized by the use of telematic facilities.

Effects of Vaginal Progesterone on Pain and Uterine Contractility in Patients with Threatened Abortion before Twelve Weeks of Pregnancy

Fifty women with previous diagnosis of inadequate luteal phase and threatened abortion underwent a prospective, randomized, double-blind study in one medical center carried out with a parallel trial. The primary objective was to establish the effects of vaginal progesterone (Crinone 8%) in reducing both pain and uterine contractions (UCs). The gel with or without (placebo) vaginal progesterone was administered once a day since the diagnosis of threatened abortion and for 5 days. The efficacy on pain symptom amelioration was evaluated by a 5-score intensity gradation, while the UCs were evaluated by ultrasound. The secondary objective of the study was to evaluate the outcome of the pregnancies. The use of progesterone was effective both on pain relief and on the frequency of the UCs that decreased after 5 days of vaginal progesterone administration (P < 0.005). The evaluation of the ongoing pregnancy and spontaneous abortion in both study groups after 60 days showed that 4 patients of group A and 8 patients of group B miscarried (P < 0.05). In conclusion, patients with threatened abortion benefit from vaginal progesterone by a reduction of UCs and pain. The use of vaginal progesterone improved the outcome of pregnancies complicated by threatened abortion and previous diagnosis of inadequate luteal phase.

[Effectiveness of Troxerutin in association with Pycnogenol in the pharmacological treatment of venous insufficiency]

AIM

The purpose of our study was to assess the different effectiveness of Troxerutin in association with Pycnogenol compared to the effects obtainable with the same pharmacological principle in monotherapy in patients suffering from venous insufficiency.

METHODS

Seventy patients with venous insufficiency of the lower extremities at the first stages of the CEAP classification (Cs1,3; Es; As 1; invalidity score 2, clinical score 1-2) were selected and subdivided into 2 groups: one of 50 and one of 20. All patients reported the following symptoms either associated or in isolation: heaviness, cramps, pruritus and pain at palpation. Evaluation of the degree of venous insufficiency was carried out by means of echo-Doppler at recruitment. The 1st group received Troxerutin (470 mg) associated with Pycnogenol (20 mg) in a dose of 1 g/day per os for 60 days; the 2nd group Troxerutin alone (300 mg) in a dose of 2 tablets twice a day per os for 60 days. Controls were set up at 30 and 60 days from the start of treatment and after a period of 3 months from the end of treatment to assess the effects on the symptomatology over time. The effectiveness of the drugs on symptomatology reported by both groups was assessed by means of an analysis of the qualitative variation of the symptoms using the score-scales method: 3=severe; 2=moderate; 1=slight; 0=absent and this variation was expressed as a percentage decrease and analysed using Student's test.

RESULTS

The results of our study after 30 days of treatment highlighted a clinical improvement in all patients with the disappearance of symptoms (score from 3 to 1) in 50% of patients in the 1st group and in 35% in the 2nd with a peak of 96% in patients of the 1st group and 80% in the 2nd at the end of treatment (60 days). This result held stable in the course of follow-up for 96% of patients in the 1st group (p<0.001) and for 50% of those in the 2nd group (p<0.005).

CONCLUSION

Comparison between the 2 groups showed that the group which received Troxerutin associated with Pycnogenol reported greater therapeutic effectiveness than the control group as regards both the rapidity of disappearance of the symptoms and as regards maintenance of the cure obtained.

Pelvic lipomatosis complicating ovarian cyst removal: a case report

Pelvic lipomatosis consists of an abdominal capsulated mass containing lipidic tissue, generally with remarkable dimensions, responsible for urinary tract disturbances. Here we describe the first case to our knowledge of accidental intraoperative diagnosis associated to an ovarian cyst in absence of objective symptoms and signs.

Fertility after laparoscopic myomectomy of large uterine myomas: operative technique and preliminary results

OBJECTIVE

The purpose of this study was to evaluate indications and complications of laparoscopic myomectomy with regard to the reproductive outcome of infertile women with a large leiomyomatous uterus.

METHODS

From January 1997 to July 1999, 144 patients underwent laparoscopic myomectomy for a myoma measuring > or = 5 cm in diameter. Indications for surgery were increase in size of myoma in infertile patients (70.8%), pain (44.4%) or abnormal bleeding (68%). Average size of myomas were 7.8 cm with a range of 5 cm to 18 cm. The myomas were intramural/submucosal (n = 108), subserosal (n = 15), intraligamentous (n = 14) and peduncolated (n = 7). The laparotomy conversion rate was 1.39% (n = 2); one case required a blood transfusion. Operating time ranged from 58 to 180 minutes with an average of 95 minutes. Average hospital stay was 2.6 days and the overall complication rate was 2.08%. Eighteen patients (12.5%) underwent second-look laparoscopy. The rate of postoperative adhesion was 33.3%; there were no adnexal adhesions. In all cases ultrasonography was done one day after the operation and five weeks postoperatively to compare wound healing, the last control showed an irregular hypodense area in only 14 patients (9.7%).

RESULTS

Twenty-six patients operated on in 1997 went on to conceive: nine vaginal deliveries, 12 Caesarean sections, four miscarriages and one ectopic pregnancy. No uterine rupture was observed. The pregnancy rate for patients submitted to laparoscopic myomectomy in 1997 (n = 38) was 34.21% at six months (n = 13) and 55.26% (n = 21) at 12 months after the procedures.

CONCLUSIONS

Our preliminary results confirm that conception occurs in the majority of infertile women with a large leiomyomatous uterus who undergo myomectomy and second-look laparoscopy leads to a low complication rate.

Depot leuprorelin acetate versus danazol in the treatment of infertile women with symptomatic endometriosis

PURPOSE OF INVESTIGATION

Endometriosis is a common finding in women with infertility, but the mechanism by which it renders a woman infertile remains unclear. The medical treatment of pelvic endometriosis includes hormonal therapy that directly attacks endometriosis lesions or indirectly by inhibiting endometrial proliferation through estrogenic deprivation. The aim of this study was to compare the efficacy and safety of leuprorelin acetate depot and danazol for endometriosis in infertile women.

METHODS

This randomized trial involved 81 women 19-41 years old with regular menses and known pelvic endometriosis who were recruited from the Fertility Center of the Second University of Naples between 1992 and 1999. Fifty-four women were given 3.75 mg of leuprolide acetate depot every 28 days for 24 weeks and the remaining 27 took 200 mg of danazol three times daily for 24 weeks. Efficacy assessments were based on pre-admission and end-of-treatment laparoscopic scores and subjective symptoms scores at 4-week intervals during and after treatment. Safety was evaluated by adverse events and clinical laboratory tests.

RESULTS

In each group, endometriosis growth and symptoms significantly improved during treatment (p < 0.001). Significantly fewer patients randomized to leuprorelin acetate (5.5%) withdrew during treatment compared with 18.5% randomized to danazol (p < 0.05). After treatment symptoms returned in each group, but severity was less than at admission at all time points (p < 0.02). Hypoestrogenic side-effects were more common in those receiving leuprorelin, particularly hot flushes, but anabolic/androgenic side-effects of weight gain and acne were more common in those receiving danazol.

CONCLUSION

Both leuprorelin acetate depot and danazol are effective in the treatment of endometriosis in infertile patients. The hypoestrogenic side-effects of leuprorelin may be better tolerated than the androgenic, anabolic effects of danazol.

Molecular mechanisms of gene silencing mediated by DNA methylation

DNA methylation and chromatin modification operate along a common pathway to repress transcription; accordingly, several experiments demonstrate that the effects of DNA methylation can spread in cis and do not require promoter modification. In order to investigate the molecular details of the inhibitory effect of methylation, we microinjected into Xenopus oocytes a series of constructs containing a human CpG-rich sequence which has been differentially methylated and cloned at different positions relative to a specific promoter. The parameters influencing the diffusion of gene silencing and the importance of histone deacetylation in the spreading effect were analyzed. We demonstrate that a few methylated cytosines can inhibit a flanking promoter but a threshold of modified sites is required to organize a stable, diffusible chromatin structure. Histone deacetylation is the main cause of gene repression only when methylation does not reach levels sufficient to establish this particular structure. Moreover, contrary to the common thought, promoter modification does not lead to the greater repressive effect; the existence of a competition between transactivators and methyl-binding proteins for the establishment of an open conformation justifies the results obtained.

Molecular mechanisms of gene silencing mediated by DNA methylation

DNA methylation and chromatin modification operate along a common pathway to repress transcription; accordingly, several experiments demonstrate that the effects of DNA methylation can spread in cis and do not require promoter modification. In order to investigate the molecular details of the inhibitory effect of methylation, we microinjected into Xenopus oocytes a series of constructs containing a human CpG-rich sequence which has been differentially methylated and cloned at different positions relative to a specific promoter. The parameters influencing the diffusion of gene silencing and the importance of histone deacetylation in the spreading effect were analyzed. We demonstrate that a few methylated cytosines can inhibit a flanking promoter but a threshold of modified sites is required to organize a stable, diffusible chromatin structure. Histone deacetylation is the main cause of gene repression only when methylation does not reach levels sufficient to establish this particular structure. Moreover, contrary to the common thought, promoter modification does not lead to the greater repressive effect; the existence of a competition between transactivators and methyl-binding proteins for the establishment of an open conformation justifies the results obtained.

Pregnancy after cytoplasmic transfer in a couple suffering from idiopathic infertility: case report

Couples suffering from idiopathic infertility are among the most difficult to treat in IVF cycles due to the unknown cause of failure to reproduce. This can lead to years of unsuccessful attempts to conceive and often the abandonment of treatment. In some couples, the only observable problem is the development of poor quality embryos. In this case report, we describe the successful use of cytoplasmic donation in a couple where the high level of embryo fragmentation and poor embryo development was thought to be the unique cause of failure to conceive after intracytoplasmic sperm injection (ICSI). We noted a strong reduction in embryo fragmentation and a consequent increase in embryo quality after the treatment. Transfer of four of the embryos receiving donor cytoplasm led to a pregnancy with two gestational sacs and the birth of healthy twins.