The Arabidopsis TFIID factor AtTAF6 controls pollen tube growth

AbstractInitiation of transcription mediated by RNA polymerase II requires a number of transcription factors among which TFIID is the major core promoter recognition factor. TFIID is composed of highly conserved factors which include the TATA-binding protein (TBP) and about 14 TBP-associated factors (TAFs). Recently, the complete Arabidopsis TAF family has been identified. To obtain functional information about Arabidopsis TAFs, we analyzed a T-DNA insertion mutant for AtTAF6. Segregation analysis showed that plants homozygous for the mutant allele were never found, indicating that inhibition of the AtTAF6 function is lethal. Genetic experiments also revealed that the male gametophyte was affected by the attaf6 mutation since significant reduced transmission of the mutant allele through the male gametophyte was observed. Detailed histological and morphological analysis showed that the T-DNA insertion in AtTAF6 specifically affects pollen tube growth, indicating that the transcriptional regulation of only a specific subset of genes is controlled by this basal transcription factor

Liver metastases and SBRT: A new paradigm?

BackgroundThe outstanding innovations made by early diagnosis, novel surgical techniques, effective chemotherapy regimens and conformal radiotherapy, have significantly improved patients overall survival and quality of life. Multidisciplinary approach to cancer has also led to an increased prevalence of patients with few, organ-confined metastases, who can experience long-term survival even if their disease is no longer localized. Liver is one of the most common site for metastatic disease from several cancers, and when metastatic disease is confined to liver, given the ability of this organ to regenerate almost to its optimal volume, surgical resection represents the standard of care because is associated with a better prognosis. Approximately 70–90% of liver metastases, however, are unresectable and a safe, effective alternative therapeutic option is necessary for these patients.Materials and methodsA review of the current literature was performed to analyze the role of SBRT in treating liver metastases from different cancers. A literature search using the terms “SBRT” and “liver metastases” was carried out in PUBMED.ResultsStereotactic body radiation therapy has shown to provide promising results in the treatment of liver metastases, thanks to the ability of this procedure to deliver a conformal high dose of radiation to the target lesion and a minimal dose to surrounding critical tissues.ConclusionStereotactic body radiation therapy is a non-invasive, well-tolerated and effective treatment for patients with liver metastases not suitable for surgical resection

Initial experience of hypofractionated radiation retreatment with true beam and flattening filter free beam in selected case reports of recurrent nasopharyngeal carcinoma

AimTo show our preliminary experience in using TrueBeam with RapidArc technology and FFF beam for stereotactic re-irradiation of nasopharyngeal carcinoma.BackgroundThanks to new advanced techniques, as well as intensity modulated radiation therapy, it is possible to approach head and neck recurrences in selected patients. Volumetric Modulated Arc Therapy (VMAT) in its RapidArc® format, permits to reduce significantly the time to deliver complex intensity modulated plans, allowing to treat hypofractionated regimes within a few minutes. With TrueBeam it is possible to perform photon beams without usage of the flattening filter. It seems possible to expect a reduction of out-of-field dose when flattening filter free (FFF) beams are used. While research into the physics domain for FFF beams is increasing, there are very few clinical data where FFF beams are applied in clinical practice.Materials and methodsWe present here the cases of 4 patients with local or regional recurrence of nasopharyngeal carcinoma. All patients were treated using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation.ResultsAll patients concluded SBRT and showed good tolerability. During follow-up, complete response at imaging evaluation (PET and/or MRI) for all treated patients was documented.ConclusionsOur preliminary experience using TrueBeam with RapidArc technology and FFF beam for stereotactic hypofractionated re-irradiation of nasopharyngeal carcinoma was safe and effective in all 4 treated patients. Longer follow-up and a larger population of study is needed to confirm these promising results

Silvicultural and phytosanitary researches in thinned chestnut coppices at different elevations in Sila (Calabria)

The results of mensurational and phytosanitary researches ten years after thinning trials in chestnut coppices (Castanea sativa Miller) in Sila, are reported.. Eight experimental areas, four located at an average elevation of 1200 m a.s.l. aged 20 yrs and four located on average at 1050 m a.s.l. aged 13 yrs, were compared. Three sub-plots were installed in each area and mensurational and phytosanitary surveys were carried out in 1997 (before and after thinning trials) and ten years later (2007) on 30 stools per sub-plot to assess bio-ecological, structural and compositional status of the standing crops. At each elevation, the experimental protocol included the following theses: thesis T (control: release of the standing crop and removal of dried up stems on the ground, only); thesis A (light thinning: removal of the dominated storey, on average 30% of coppice shoots, poorly shaped, both withered and green); thesis B (moderate thinning: removal from the dominated up to the dominant storey = 43% of the shoots, both dried up and green); thesis C (heavy thinning: removal = 62% of coppice shoots, both withered and green). Results highlighted the significance of thinnings in the cultivation of chestnut coppices. As for silviculture and growth pattern, the surveying ten years later showed the following outcomes: reduction of shoots mortality, according to the thinning intensity from A to C (by comparing the number of dried up coppice shoots surveyed in the control theses); a higher number of coppice shoots in the commercial category “average stems” in the thinned plots; the higher percentage increment in dbh, basal area and volume in the sub-plots undergoing thinning A and C at the elevation of 1050 m and, in general, with thesis C at both elevations; the complete recovery of canopy cover even in the sub-plots heavily thinned. As for the phytosanitary aspects, the research has been oriented on the chestnut blight caused by Cryphonectria parasitica, due to the lack of symptomatology of “ink disease” in the sub-plots, even though present on the same territory. The hypovirulence is predominant and steady with time for the high presence of healing and healed cankers. Among the factors of coppice shoots mortality, blight plays a minor role here. The disease spreads regardless of thinnings and silviculture can operate therefore independently to get a wide range of assortments, from poles to timber. Basically, thinning release has to ensure the predominance and steady presence of hypovirulence in the chestnut stands. In this way, foci for the natural spreading of hypovirulent strains are being created and preserved. This seem to be a basic tool to ensure a phytosanitary equilibrium between the parasite and the host in chestnut coppices, which still represent an important economic resource in Calabria as well as in several other Italian regions

SMaRT modulation of tau isoforms rescues cognitive and motor impairments in a preclinical model of tauopathy

Tau is a microtubule-associated protein predominantly expressed in neurons, which participates in microtubule polymerization and axonal transport. Abnormal tau metabolism leads to neurodegenerative diseases named tauopathies, such as Alzheimer’s disease and frontotemporal dementia. The alternative splicing of exon 10 (E10) in the primary transcript produces tau protein isoforms with three (3R) or four (4R) microtubule binding repeats, which are found in equal amounts in the normal adult human brain. Several tauopathies are associated with abnormal E10 alternative splicing, leading to an imbalance between 3R and 4R isoforms, which underlies disease. Correction of such imbalance represents a potential disease-modifying therapy for those tauopathies. We have previously optimized a trans-splicing RNA reprogramming strategy to modulate the 3R:4R tau content in a mouse model of tauopathy related to tau mis-splicing (htau mice), and showed that local modulation of E10 inclusion in the prefrontal cortex prevents cognitive decline, neuronal firing impairments and hyperphosphorylated tau accumulation. Furthermore, local shifting of 3R–4R tau into the striatum of htau mice prevented motor coordination deficits. However, a major bottleneck of our previous work is that local splicing regulation was performed in young mice, before the onset of pathological phenotypes. Here we tested whether regulation of tau E10 splicing could rescue tau pathology phenotypes in htau mice, after the onset of cognitive and motor impairments, comparable to early stages of human tauopathies. To determine phenotypic time course and affected brain nuclei, we assessed htau mice using behavioural tests and microPET FDG imaging over time, similarly to diagnosis methods used in patients. Based on these analyses, we performed local delivery of pre-trans splicing molecules to regulate E10 inclusion either into the medial prefrontal cortex (mPFC) or the striatum at 6-month-old once behavioral phenotypes and metabolic changes were detected. Tau isoforms modulation into the mPFC restored cognitive performance in mice that previously showed mild to severe memory impairment while motor coordination deficit was rescued after striatal injection of trans-splicing molecules. Our data suggest that tau regulation could recover pathological phenotypes early after phenotypic onset, raising promising perspectives for the use of RNA based therapies in tauopathies related to MAPT abnormal splicing.Fil: Muñiz, Javier Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Facal, Carolina Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Urrutia, Leandro. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Clerici Delville, Ramiro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; ArgentinaFil: Damianich, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Ferrario, Juan Esteban. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biociencias, Biotecnología y Biología Traslacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Falasco, Germán Alfredo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Avale, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

Evaluation of plan complexity and dosimetric plan quality of total marrow and lymphoid irradiation using volumetric modulated arc therapy

PurposeTo assess the impact of the planner's experience and optimization algorithm on the plan quality and complexity of total marrow and lymphoid irradiation (TMLI) delivered by means of volumetric modulated arc therapy (VMAT) over 2010-2022 at our institute. MethodsEighty-two consecutive TMLI plans were considered. Three complexity indices were computed to characterize the plans in terms of leaf gap size, irregularity of beam apertures, and modulation complexity. Dosimetric points of the target volume (D2%) and organs at risk (OAR) (Dmean) were automatically extracted to combine them with plan complexity and obtain a global quality score (GQS). The analysis was stratified based on the different optimization algorithms used over the years, including a knowledge-based (KB) model. Patient-specific quality assurance (QA) using Portal Dosimetry was performed retrospectively, and the gamma agreement index (GAI) was investigated in conjunction with plan complexity. ResultsPlan complexity significantly reduced over the years (r = -0.50, p < 0.01). Significant differences in plan complexity and plan dosimetric quality among the different algorithms were observed. Moreover, the KB model allowed to achieve significantly better dosimetric results to the OARs. The plan quality remained similar or even improved during the years and when moving to a newer algorithm, with GQS increasing from 0.019 +/- 0.002 to 0.025 +/- 0.003 (p < 0.01). The significant correlation between GQS and time (r = 0.33, p = 0.01) indicated that the planner's experience was relevant to improve the plan quality of TMLI plans. Significant correlations between the GAI and the complexity metrics (r = -0.71, p < 0.01) were also found. ConclusionBoth the planner's experience and algorithm version are crucial to achieve an optimal plan quality in TMLI plans. Thus, the impact of the optimization algorithm should be carefully evaluated when a new algorithm is introduced and in system upgrades. Knowledge-based strategies can be useful to increase standardization and improve plan quality of TMLI treatments

Automatic planning of the lower extremities for total marrow irradiation using volumetric modulated arc therapy

Purpose Total marrow (and lymphoid) irradiation (TMI-TMLI) is limited by the couch travel range of modern linacs, which forces the treatment delivery to be split into two plans with opposite orientations: a head-first supine upper-body plan, and a feet-first supine lower extremities plan. A specific field junction is thus needed to obtain adequate target coverage in the overlap region of the two plans. In this study, an automatic procedure was developed for field junction creation and lower extremities plan optimization. Methods Ten patients treated with TMI-TMLI at our institution were selected retrospectively. The planning of the lower extremities was performed automatically. Target volume parameters (CTV_J-V-98% > 98%) at the junction region and several dose statistics (D-98%, D-mean, and D-2%) were compared between automatic and manual plans. The modulation complexity score (MCS) was used to assess plan complexity. Results The automatic procedure required 60-90 min, depending on the case. All automatic plans achieved clinically acceptable dosimetric results (CTV_J-V-98% > 98%), with significant differences found at the junction region, where D-mean and D-2% increased on average by 2.4% (p < 0.03) and 3.0% (p < 0.02), respectively. Similar plan complexity was observed (median MCS = 0.12). Since March 2022, the automatic procedure has been introduced in our clinic, reducing the TMI-TMLI simulation-to-delivery schedule by 2 days. Conclusion The developed procedure allowed treatment planning of TMI-TMLI to be streamlined, increasing efficiency and standardization, preventing human errors, while maintaining the dosimetric plan quality and complexity of manual plans. Automated strategies can simplify the future adoption and clinical implementation of TMI-TMLI treatments in new centers

Multimodality therapy approaches, local and systemic treatment, compared with chemotherapy alone in recurrent glioblastoma

BACKGROUND: Long-term local control in Glioblastoma is rarely achieved and nearly all patients relapse. In this study we evaluated the clinical effect of different treatment approaches in recurrent patients. METHODS: Forty-three patients, with median age of 51 years were evaluated for salvage treatment: re-resection and/or re-irradiation plus chemotherapy or chemotherapy alone. Response was recorded using the Response Assessment in Neuro-Oncology criteria. Hematologic and non-hematologic toxicities were graded according to Common Terminology Criteria for Adverse Events 4.0. Twenty-one patients underwent chemotherapy combined with local treatment, surgery and/or radiation therapy, and 22 underwent chemotherapy only. RESULTS: The median follow up was 7 months (range 3–28 months). The 1 and 2-years Progression Free Survival was 65 and 10 % for combined treatment and 22 and 0 % for chemotherapy alone (p < 0.01). The 1 and 2-years overall survival was 69 and 29 % for combined and 26 and 0 % for chemotherapy alone (p < 0.01). No toxicity greater than grade 2 was recorded. CONCLUSION: These data showed that in glioblastoma recurrence the combination of several approaches in a limited group of patients is more effective than a single treatment alone. This stress the importance of multimodality treatment whenever clinically feasible

Immunological predictors of CD4+ T cell decline in antiretroviral treatment interruptions

<p>Abstract</p> <p>Background</p> <p>The common response to stopping anti-HIV treatment is an increase of HIV-RNA load and decrease in CD4⁺, but not all the patients have similar responses to this therapeutic strategy. The aim was to identify predictive markers of CD4⁺cell count declines to < 350/μL in CD4-guided antiretroviral treatment interruptions.</p> <p>Methods</p> <p>27 HIV-infected patients participated in a prospective multicenter study in with a 24 month follow-up. Patients on stable highly active antiretroviral therapy (HAART), with CD4⁺count > 600/μL, and HIV-RNA < 50 copies/ml for at least 6 months were offered the option to discontinue antiretroviral therapy. The main outcome was a decline in CD4⁺cell count to < 350/μL.</p> <p>Results</p> <p>After 24 months of follow-up, 16 of 27 (59%) patients (who discontinued therapy) experienced declines in CD4⁺cell count to < 350/μL. Patients with a CD4⁺nadir of < 200 cells/μL had a greater risk of restarting therapy during the follow-up (RR (CI95%): 3.37 (1.07; 10.36)). Interestingly, lymphoproliferative responses to <it>Mycobacterium tuberculosis </it>purified protein derivative (PPD) below 10000 c.p.m. at baseline (4.77 (1.07; 21.12)), IL-4 production above 100 pg/mL at baseline (5.95 (1.76; 20.07)) in PBMC cultured with PPD, and increased IL-4 production of PBMC with p24 antigen at baseline (1.25 (1.01; 1.55)) were associated to declines in CD4⁺cell count to < 350/μL.</p> <p>Conclusion</p> <p>Both the number (CD4⁺nadir) and the functional activity of CD4⁺(lymphoproliferative response to PPD) predict the CD4⁺decrease associated with discontinuation of ART in patients with controlled viremia.</p