Regulation with cell size ensures mitochondrial DNA homeostasis during cell growth

To maintain stable DNA concentrations, proliferating cells need to coordinate DNA replication with cell growth. For nuclear DNA, eukaryotic cells achieve this by coupling DNA replication to cell-cycle progression, ensuring that DNA is doubled exactly once per cell cycle. By contrast, mitochondrial DNA replication is typically not strictly coupled to the cell cycle, leaving the open question of how cells maintain the correct amount of mitochondrial DNA during cell growth. Here, we show that in budding yeast, mitochondrial DNA copy number increases with cell volume, both in asynchronously cycling populations and during G1 arrest. Our findings suggest that cell-volume-dependent mitochondrial DNA maintenance is achieved through nuclear-encoded limiting factors, including the mitochondrial DNA polymerase Mip1 and the packaging factor Abf2, whose amount increases in proportion to cell volume. By directly linking mitochondrial DNA maintenance to nuclear protein synthesis and thus cell growth, constant mitochondrial DNA concentrations can be robustly maintained without a need for cell-cycle-dependent regulation.

An mTOR/RNA pol I axis shapes chromatin architecture in response to fasting

Chromatin architecture is a fundamental mediator of genome function. Fasting is a major environmental cue across the animal kingdom. Yet, how it impacts on 3D genome organization is unknown. Here, we show that fasting induces a reversible and large-scale spatial reorganization of chromatin in C. elegans . This fasting-induced 3D genome reorganization requires inhibition of the nutrient-sensing mTOR pathway, a major regulator of ribosome biogenesis. Remarkably, loss of transcription by RNA Pol I, but not RNA Pol II nor Pol III, induces a similar 3D genome reorganization in fed animals, and prevents the restoration of the fed-state architecture upon restoring nutrients to fasted animals. Our work documents the first large-scale chromatin reorganization triggered by fasting and reveals that mTOR and RNA Pol I shape genome architecture in response to nutrients.

Single-molecule experiments reveal the elbow as an essential folding guide in SMC coiled-coil arms

Structural maintenance of chromosome (SMC) complexes form ring-like structures through exceptional elongated coiled-coils (CCs). Recent studies found that variable CC conformations, including open and collapsed forms, which might result from discontinuities in the CC, facilitate the diverse functions of SMCs in DNA organization. However, a detailed description of the SMC CC architecture is still missing. Here, we study the structural composition and mechanical properties of SMC proteins with optical tweezers unfolding experiments using the isolated Psm3 CC as a model system. We find a comparatively unstable protein with three unzipping intermediates, which we could directly assign to CC features by crosslinking experiments and state-of-the-art prediction software. Particularly, the CC elbow is shown to be a flexible, potentially non-structured feature, which divides the CC into sections, induces a pairing shift from one CC strand to the other and could facilitate large-scale conformational changes, most likely via thermal fluctuations of the flanking CC sections. A replacement of the elbow amino acids hinders folding of the consecutive CC region and frequently leads to non-native misalignments, revealing the elbow as a guide for proper folding. Additional in vivo manipulation of the elbow flexibility resulted in impaired cohesin complexes, which directly link the sensitive CC architecture to the biological function of cohesin.

Segmentation, tracking and cell cycle analysis of live-cell imaging data with Cell-ACDC

Background

High-throughput live-cell imaging is a powerful tool to study dynamic cellular processes in single cells but creates a bottleneck at the stage of data analysis, due to the large amount of data generated and limitations of analytical pipelines. Recent progress on deep learning dramatically improved cell segmentation and tracking. Nevertheless, manual data validation and correction is typically still required and tools spanning the complete range of image analysis are still needed.

Results

We present Cell-ACDC, an open-source user-friendly GUI-based framework written in Python, for segmentation, tracking and cell cycle annotations. We included state-of-the-art deep learning models for single-cell segmentation of mammalian and yeast cells alongside cell tracking methods and an intuitive, semi-automated workflow for cell cycle annotation of single cells. Using Cell-ACDC, we found that mTOR activity in hematopoietic stem cells is largely independent of cell volume. By contrast, smaller cells exhibit higher p38 activity, consistent with a role of p38 in regulation of cell size. Additionally, we show that, in S. cerevisiae, histone Htb1 concentrations decrease with replicative age.

Conclusions

Cell-ACDC provides a framework for the application of state-of-the-art deep learning models to the analysis of live cell imaging data without programming knowledge. Furthermore, it allows for visualization and correction of segmentation and tracking errors as well as annotation of cell cycle stages. We embedded several smart algorithms that make the correction and annotation process fast and intuitive. Finally, the open-source and modularized nature of Cell-ACDC will enable simple and fast integration of new deep learning-based and traditional methods for cell segmentation, tracking, and downstream image analysis.

Source code: https://github.com/SchmollerLab/Cell_ACDC

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-022-01372-6.

AB1580-PARE REMISSION: IS IT UNKNOWN?

Background

Remission is the alleviation or disappearance of the symptoms of a pathology. It may be due to the cessation of a pathogenic action, its overcoming by the body’s defense mechanisms, the implementation of adequate therapy. The term is used when the phenomenon is transitory and can have variable duration, even very long (months or years). However, the morbid process persists in the body and then fatally returns to recur.

But how much do patients with chronic rheumatological diseases know? How many of them know this word and, among those who know it, how many correctly understand its full meaning? Here is the objective of the campaign: to verify the level of awareness among rheumatological patients with respect to the concept of remission of the pathology.

Objectives

The objective of the Association, in collaboration with SIR (which has already granted the patronage to the campaign) is to verify, in 3 years, how and how much awareness has improved on the concept of remission between patients and if, and how much, doctor-patient communication will be improved on the subject.

Methods

This awareness campaign is on the concept of remission will start, implemented with different tools:

1 – Informative booklet on the concept of remission, on what it is and how it can be achieved. And to maintain, both from the point of view of the rheumatologist and from the patient’s point of view. The booklet will be accompanied by the results of the questionnaire mentioned above.

2- Ideation, creation and realization of a Facebook page: https://www.facebook.com/ObiettivoRemissione/ which will be used as a vehicle for a series of informative contents on the concept of remission and for an emotional video intended for the target of patients and their family:

Results

Started in 2020, the campaign is still ongoing and the first preliminary results will be delivered in the last quarter of 2022

Conclusion

A survey conducted on 1,300 respondents, of which 93% were patients or family members of patients, shows that 26% do not know the concept of remission and only half report having heard about it from their referring physician.

From an SEO survey conducted on the main search engines, then, it is clear that the concept of remission in the context of rheumatic diseases is totally absent from the Internet which is, unfortunately or fortunately, at this moment, the first research outpost by of patients or potential patients on health issues.

Disclosure of Interests

None declared

Multimodal real-time frequency tracking of cantilever arrays in liquid environment for biodetection: Comprehensive setup and performance analysis

We present a nanomechanical platform for real-time quantitative label-free detection of target biomolecules in a liquid environment with mass sensitivity down to few pg. Newly fabricated arrays of up to 18 cantilevers are integrated in a micromachined fluidic chamber, connected to software-controlled fluidic pumps for automated sample injections. We discuss two functionalization approaches to independently sensitize the interface of different cantilevers. A custom piezo-stack actuator and optical readout system enable the measurement of resonance frequencies up to 2 MHz. We implement a new measurement strategy based on a phase-locked loop (PLL), built via in-house developed software. The PLL allows us to track, within the same experiment, the evolution of resonance frequency over time of up to four modes for all the cantilevers in the array. With respect to the previous measurement technique, based on standard frequency sweep, the PLL enhances the estimated detection limit of the device by a factor of 7 (down to 2 pg in 5 min integration time) and the time resolution by more than threefold (below 15 s), being on par with commercial gold-standard techniques. The detection limit and noise of the new setup are investigated via Allan deviation and standard deviation analysis, considering different resonance modes and interface chemistries. As a proof-of-concept, we show the immobilization and label-free in situ detection of live bacterial cells (E. coli), demonstrating qualitative and quantitative agreement in the mechanical response of three different resonance modes.

AB0918-PARE FAMILY PLANNING AND RMDS: A SURVEY

Background:

It is well known and universally aknowledged that RMDs are not related to old age, as those who are affected by these illness between 30 and 45 years old are a big number, perhaps the biggest one. Therefore, family planning and pregnancy are topics even more actual and their management is certainly one of the biggest source of distress and troubles in people affected by RMDs and their spouses.

Objectives:

to define and deeply understand the problem’s dimension, ANMAR made a survey according to the CAPIRE Observatory.

Methods:

an pposite questionnaire was given to patients waiting for a rheumatological consultation, during 6 months in 2020.

Results:

Over 300 women with an RMD fulfilled the questionnaire:

7 on 10 women are trying to become pregnant

51% of them did not notice it to their Rheumatologist.

57% of them has been already pregnant.

Conclusion:

In Italy, women with RMDs are over 3.5 millions and the a lot of them are women of childbearing potential.

As therapies actually used are really effective, but may induce side effects on the reproductive system, it is absolutely needed to inform the Rheumatologist about the intent to procreate and to have suggestions about the correct chice of contracception models.

Communication between patient and Rheumatologist must be improoved, even in this important topic.

Disclosure of Interests:

None declared

Nanotechnological immunoassay for rapid label-free analysis of candidate malaria vaccines

Malaria is a life-threatening epidemic disease with half of the world's population at risk. Although its incidence rate has fallen since 2010, this ratio dramatically stalled between 2014 and 2018. New fast and optimized tools in vaccine analysis and seroconversion testing are critically needed. We developed a clinical diagnostic device based on piezo-actuated nanoresonators that perform as quantitative in situ calibrated nano-bio sensors for specific detection of multiple target molecules in serum samples. The immunoassay successfully diagnoses humoral immune responses induced by malaria vaccine candidates and reveals the timeline and stage of the infection. We applied the newly developed strategy to a variety of different samples, from pure antibody/vaccine solutions, to blood samples from clinical trials on both naïve and pre-exposed malaria volunteers from sub-Saharan countries. Our nanomechanical assay provides a direct one-step label-free quantitative immunoassay that is on par with the gold-standard, multi-step enzyme-linked immunosorbent assay (ELISA). We achieve a limit of detection of few pg ml-1, or sub-pM concentrations. The 6 μl sample volume allows more than 50 experiments from one finger prick. Furthermore, we simultaneously detected multiple analytes by differential functionalization of multiple sensors in parallel. The inherent differential read-out with in situ controls reduces false positive results. Due to the faster turnaround time, the minimal volume required and the automatized handling system, this technique has great potential for miniaturization and routine diagnostics in pandemic emergencies.

Towards personalised rapid label free miRNA detection for cancer and liver injury diagnostics in cell lysates and blood based samples

Advances in prevention, diagnosis and therapy are coupled to innovation and development of new medical tools, leading to improved patient prognosis. We developed an automatic biosensor platform that could provide a non-invasive, rapid and personalised diagnosis using nanomechanical cantilever sensors. miRNA are involved in gene expression and are extractable biomarkers for multiple diseases. We detected specific expression patterns of miRNA relevant to cancer and adverse drug effects directly in cell lysates or blood based samples using only a few microliters of sample within one hour. Specific miRNA hybridisation to the upper cantilever surface induces physical bending of the sensor which is detected by monitoring the position of a laser that reflects from the sensors surface. Internal reference sensors negate environmental and nonspecific effects. We showed that the sensitivity of label free cantilever nanomechanical sensing of miRNA surpasses that of surface plasmon resonance by more than three orders of magnitude. A cancer associated miRNA expression profile from cell lysates and one associated with hepatocytes derived from necrotic liver tissue in blood-based samples has been successfully detected. Our label free mechanical approach displays the capability to perform in relevant clinical samples while also obtaining comparable results to PCR based techniques. Without the need to individually extend, amplify or label each target allowing multitarget analysis from one sample.

Gastric Cancer: Histopathologic Patterns According to Lauren's Classification in a High-Risk Area and Distribution by Residence

A total of 1061 advanced gastric cancers with histologic confirmation, diagnosed from 1973 to 1982 at the Morgagni-Pierantoni Hospital (Forlì) were reclassified according to Lauren, and histologic types were related to the source of the histologic specimen, sex, age at diagnosis, place of birth and residence. This large case series showed a high percentage of intestinal type cancers, consistent with the high risk for gastric cancer which characterizes the area under study. Intestinal type carcinomas tend to be represented more in the older age groups, in males and in subjects born in the Forlì province and resident in hilly and mountainous areas. The distribution over time of biopsy specimens in this case series showed an increased use of gastroscopy for diagnosis in the population under study.

Interobserver Reproducibility of Immunohistochemical Her-2/Neu Assessment in Human Breast Cancer: An Update from INQAT round III

The clinical interest in HER-2/neu is related to trastuzumab, a drug used to treat patients with invasive breast carcinoma overexpressing the HER-2/neu protein. It is very important to correctly identify those patients who may benefit from trastuzumab by accurate assessment of the HER-2/neu status. Of the various methods available, the Dako Herceptest for immunohistochemical assay is considered the most reliable to reach this goal. The aim of this study was to investigate within a group of Italian laboratories the reproducibility of the results of HER-2/neu assessment by means of the Dako scoring system on slides stained with the Herceptest kit. This study was also conceived as the continuation of one of our previous studies, which was similar in its aims but different in the classification criteria adopted. Our results show that, whereas the intra-observer reproducibility was generally satisfactory, the interobserver reproducibility was not. Moreover, our findings confirm that the two extreme classes (0 and 3+) are more easy to identify than the other two and that the Herceptest does not allow to discriminate optimally between scoring classes 2+ and 3+. These findings are relevant in clinical practice where the treatment choice is based on categories defined by this assay, suggesting the need of adopting educational programs and/or new reference materials to improve the assay performance.

Nanomechanical clinical coagulation diagnostics and monitoring of therapies

Clinical coagulation diagnostics often requires multiple tests. Coagulation times are a first indication of an abnormal coagulation process, such as a coagulation factor deficiency. To determine the specific deficient factor, additional immuno- and/or enzyme assays are necessary. Currently, every clinical laboratory has to normalize their assays (international normalized ratio, INR), and therefore, certain variability within the clinical analytics exists. We report a novel strategy for a quick, reliable and quantitative diagnosis of blood coagulation diseases (e.g. haemophilia) and for monitoring factor replacement and anticoagulant therapies (e.g. heparin treatment). We exploit nano-oscillations of microcantilevers for real-time measurements of the evolving blood plasma clot strength (viscosity). The sensors are oscillated at multiple high resonance mode numbers, in order to minimise the oscillation amplitude (a few nanometers), to provide direct internal control and to increase the quality factor. Along with the activated thromboplastin time (aPTT) and prothrombin time (PT) other parameters important for thrombosis diagnostics can be obtained, including the final clot strength and the fibrinolysis time. We demonstrate the dependence of the parameters on factor deficiencies and we diagnose a specific factor deficiency through an integrated and quantitative in situ immunoassay. This approach does not require continuous calibration since it delivers an absolute quantity (clot strength). The low sample volume required (a few μl) and the ability to measure different parameters within the same test (PT, aPTT and global coagulation assay) make the presented technique a versatile point-of-care device for clinical coagulation diagnostics.

Treatment of brain arteriovenous malformations by double arterial catheterization with simultaneous injection of Onyx: retrospective series of 17 patients

BACKGROUND AND PURPOSE

The use of Onyx in the treatment of intracranial AVMs has increased the cure rate of endovascular embolization compared with the use of liquid adhesive agents. Inadvertent occlusion of the draining veins before the complete exclusion of the nidus constitutes a major risk of bleeding. We report a case series using the technique of double simultaneous arterial catheterization as an approach to achieve the complete exclusion of the nidus before reaching the venous drainage, through a more controlled hemodynamic filling.

MATERIALS AND METHODS

Between April 2008 and November 2009, 17 patients with brain AVMs were treated by the DACT. The mean age of the patients was 32.7 years (range, 6-54 years), with 9 females and 8 males. The clinical onset was characterized by intracranial hemorrhage in 8 patients and by seizures in 7. The size of the AVMs ranged from 13 to 54 mm (average, 26.2 mm). The DACT was always used with the objective of curing the AVM.

RESULTS

All 17 patients completed the EVT. The average number of sessions conducted was 1.4 (range, 1-3 sessions), with the average injection amount of 6.9 mL of Onyx (range, 2-25.2 mL). Sixteen AVMs (94.1%) were angiographically cured by embolization. Clinical complications occurred in 2 patients (11.7%); 1 of these was permanent (5.9%). No deaths were registered.

CONCLUSIONS

This preliminary series shows that the DACT presents satisfactory results when used with curative intent.

[Benign solitary fibrous tumor of the pancreas: a rare location of extra-pleural fibrous tumor. Single case report and review of the literature]

BACKGROUND/AIMS

Extra pleural solitary fibrous are very rare, but occasionally they appear in extraserosal soft tissues or parenchymatous organs, where their diagnosis is often a challenge. In this report we describe the case of a patient with a single primary solitary fibrous tumor of the pancreatic head with a review of the literature.

METHODS/RESULTS

A 62 years old woman underwent a Traverso-Longmire procedure in November 2004. Sixteen months after resection there is no evidence of recurrence. The tumour showed immunoreactivity for CD34, CD99, bcl-2, vimentin and smooth muscle actin. MIB-1 proliferating activity was < 5%.

CONCLUSIONS

Extra pleural solitary fibrous tumor are often benign lesions. In the pancreas only 2 cases have been described so far. Other mesenchymal tumours that may occur in the pancreas include leiomyosarcoma, tumours of the peripheral nerve sheath, fibrous histiocytic tumours and rare vascular tumours. The differential diagnosis is mainly based on immunohistochemistry. The surgical approach is fundamental for the treatment of solitary fibrous tumour.

Flow-cytometric determination of tumor cells in lymph nodes

In solid tumors, metastasis occurs through the dissemination of tumor cells in the bloodstream and the lymphatic system. In particular, lymph node infiltration gives useful prognostic information and represents one of the most important factors for selecting the type of clinical treatment in disease management. Furthermore, the analysis of lymph node infiltration has become important for identifying patients with breast cancer or malignant melanoma who may be candidates for regional lymph node dissection. Tumor cells in lymph nodes are currently identified in tissue sections using morphological and immunohistochemical analyses, but these approaches are time-consuming, and micrometastases may escape detection. The aim of the present study was to define the potential of a flow cytometric (FCM) determination based on cell size and autofluorescence to shorten the time required for lymph node analysis. The sensitivity of the FCM approach, defined on mixtures of tumor cells from established cell lines and peripheral blood lymphocytes (PBL(s)) at different concentrations, was 1 tumor cell/1,000 PBL(s). FCM analysis was performed on 89 lymph nodes, 29 from breast, 41 from lung and 19 from colon cancer patients. Agreement between FCM and morphological results, used as gold standard, was observed in 83% of the cases, and there was a 90% sensitivity to the FCM approach for each tumor type. Disagreement was observed for 15 lymph nodes and was due, in the majority of cases (80%), to FCM-positive and morphologically negative results. A large number of patients and a more accurate pathological examination of consecutive histological sections of lymph nodes are needed to further evaluate the validity of the FCM approach.

Increased risk of autoimmune hypothyroidism in patients affected by retinitis pigmentosa

Patients with Retinitis Pigmentosa (RP) show hemeralopia, restricted field of vision and reduced visual acuity, owing to the degeneration and proliferation of photoreceptors and a retinal pigment epithelium. The prevalence in Italy is 1:4,000. A certain number of "syndromic" associations have been described, and, in particular, also that with hypothyroidism, but very few cases have been studied. We describe a family of 40 people, spanning four generations, in which we have recorded the presence of autosomic dominant RP, associated with autoimmune hypothyroidism or with circulating antithyroid autoantibodies (ATA), currently considered as the expression of active autoimmune thyroiditis or a risk factor for this complaint. We measured, in all members, TSH, FT3, FT4, antithyroglobulin and antithyroperoxidase autoantibodies. A fundus oculi examination was performed in every subject, as well as a careful examine of the anterior region on the neck. A control population of 100 healthy people was also studied. Our data show a higher prevalence of ATA, statistically significant, in the patients with RP and in their relatives, compared with the control population and the data from the literature (13 cases over 40 = 32.5%; p < 0.01). 3 patients with RP and ATA were affected by clinically evident hypothyroidism. 10 patients with ATA were clinically euthyroid; 8 patients affected by RP did not show circulating ATA at the time of the study. The interest for the physician in this "syndromic" retinal distrophy reflects the need, emerging from our data, to test the thyroid function in the subjects with RP and in members of their families, since circulating ATA are considered a risk factor for the development of autoimmune hypothyroidism.

Adenomyoma of the stomach. Report of a case and review of the literature

A case of adenomyoma of the prepyloric antrum and a review of the previous reported in the literature are presented. The tumor is composed of cysts and glandular structures lined by cuboidal-to-columnar epithelium surrounded by hypertrophic smooth muscle bundles. Furthermore, glands resembling Brunner's and/or heterotopic pancreatic tissue are present in some patients. The endoscopic characteristics of the lesion are discussed, as well as the diagnostic and therapeutic approaches.

[Community-acquired bronchopneumonias in the elderly. The cost-benefit ratio in some plans of antibiotic therapy]

Community-acquired pneumonias represent the first cause of mortality due to a infectious disease, and determine more than 500,000 hospitalizations per year in the USA: moreover, they are the terminal event in many geriatric patients. Although the etiological microbial agents responsible for the majority of such pneumonias, Haemophilus influenzae and Streptococcus pneumoniae, are still sensitive to traditional antibiotics, as ampicillin, many doctors treat community acquired pneumonias with more recent and expensive antibiotics, as the third generation cephalosporins or other beta-lactamines, so enhancing the cost of the treatments, without a known, real advantage with respect to the older therapies. In this study, to evaluate whether the use of the latter antibiotics improves the outcome of community acquired pneumonias of the elderly with respect to the traditional therapy with ampicillin, we studied 123 hospitalized patients older than 65 years, affected by community-acquired pneumonia, simple or complicated. We also evaluated the cost/benefit ratio of every single treatment. Our data demonstrate that the recent antibiotics do not influence the outcome of the disease of the elderly: in particular, they do not affect the duration of the hospitalization, do not have a lower incidence of side effects, do not show a better efficacy versus ampicillin. The cost of the treatment with ampicillin is about one third of the cost of a third-generation cephalosporin treatment. We conclude that the treatment of choice for community acquired pneumonias of the elderly is ampicillin; only in few cases, as in nosocomial or in nursing homes pneumonias, third-generation cephalosporins or other antibiotics are necessary.

[Value of the in situ hybridization technique in the diagnosis of human papilloma virus infections of the uterine cervix. Correlations between the human papilloma virus type and the morphological features]

Clinico-pathologic, epidemiologic and molecular analytic studies have shown that: i) the squamous cancer of the uterine cervix derives from intraepithelial lesions with different degrees of atypia; ii) human papillomavirus (HPV) can play a fundamental role in the progression of these lesions. We have examined 219 uterine cervix biopsies by means of the in situ hybridization technique (ISH) using biotinylated probes for 6/11, 16/18 and 31/35/51 HPV strains. The histologic lesions were as follows: 104 (49.7%) focal koilocytotic lesions 26 (11.8%) low grade intraepithelial lesions (SIL) 45 (20.5%) high grade intraepithelial lesions (SIL) 18 (8.2%) condylomata acuminata 21 (9.8%) invasive cancers. The percentage of the positivity found in the whole material examined is 14.1%. In particular, none of the 109 cases of focal koilocytotic lesions was positive, whereas the 28.1% of the remaining 110 biopsies turned out to contain HPV. We hypothesize that our small percentage of positivity in preinvasive and invasive lesions of the uterine cervix can be due to the fact that the HPV is not the only cancerogenic factor involved, although the possibility of a low sensitivity of the technique cannot completely be excluded.

[Epidermoid cyst of the spleen. Presentation of a case]

Cystic lesions of the spleen are unusual. They are classified essentially as: parasitic or nonparasitic, based on their etiology, and true or pseudo based on the presence or absence of lining epithelium. The pathogenesis of true cysts is unknown and numerous hypotheses are given by different Authors. After a short review of the literature, the Authors describe the clinical and pathological data of a case of epithelial (epidermoid) splenic cyst occurs in a 12-year-old woman. The Authors put forward some personal observations on pathogenesis, still doubtful, by means of histochemical and immunohistochemical study.

[Study on the sensibility "in vitro" to antibiotics of 77 strains of "Pseudomonas aeruginosa" (author's transl)]

It has been studied the sensibility in vitro to antibiotics of 77 strains of Pseudomonas aeruginosa isolated from various biological materials derived from sheltered patients. The best results have been obtained with colistin, carbenicillin and gentamicin which have done inhibition respectively in 80.5%, 70.1% and 50.6% of the strains.