Generation of iPSC lines derived from skin fibroblasts of two healthy controls using non-transmissible form of Sendai Virus.

We established two iPSC lines starting from skin fibroblasts of two healthy individuals using Sendai-virus-based technique. The obtained iPSCs were characterized showing same STR profile as starting fibroblasts, normal karyotype, loss of stemness vectors, expression of stemness markers, both through real-time PCR and immunofluorescence, (OCT4, SOX2, TRA-1-60, NANOG and SSEA4) and in vitro differentiation into three germ layers.

Digital morphology compared to the optical microscope: A validation study on reporting bone marrow aspirates.

INTRODUCTION: This study aims to evaluate the effectiveness and reliability of the utilization for clinical reporting of the evaluation of digital images of bone marrow aspirates by morphologists and their comparability with the classic microscopic morphological evaluation. METHODS: We scanned 180 consecutive bone marrow needle aspirates smears using the "Metafer4 VSlide" whole slide imaging (WSI) digital scanning system. We evaluated the statistical comparability and the risk of bias of the microscopic readings with those performed on the screen on the digitized medullary images. RESULTS: The evaluation of cellularity on the screen was equivalent, with a higher frequency of "normal" than the analysis of digital preparations. The means and medians of the percentage values obtained on the different cell populations with the microscopic and digital reading were comparable as the main categories are concerned, with an average difference equal to 0 for the neutrophilic and eosinophilic granulocytic series, at -0.2% for the total myeloid cells, at 1.2% for the erythroid series, at -0.4% for the lymphocytes and at -0.4% for the blasts. Dysplastic features were consistently identified in 69/71 cell lineages. CONCLUSION: Our study demonstrated that screen evaluation of digitized bone marrow needle aspirates provides quantitative and qualitative results comparable to traditional microscopic analysis of the corresponding slide smears. Digital images offer significant benefits in reducing the workload of experienced operators, reproducibility and sharing of observations, and image preservation. Even in routine diagnostic activities, their use does not alter the quality of the results obtained in evaluating bone marrow needle aspirates.

Prognostic factors in gastric cancer patients: a 10-year mono-institutional experience.

Introduction: Gastric cancer (GC) is one of the main causes of death from cancer globally. Long-term survival, especially in Western countries, remains dismal, with no significant improvements in recent years. Therefore, precise identification of clinical and pathological risk factors is crucial for prognosis, as it allows a better selection of patients suitable for oncologically radical treatments and contributes to longer survivals. Methods: We devised a retrospective observational longitudinal study over 10 years of experience with GC patients operated with curative intent. Results: Several factors were thoroughly investigated in a multivariate analysis to look for significance as independent risk factors for disease-free survival. Our results showed that only BMI, pTNM, and lymph node ratio expressed hazard ratios with implications for survival in our series of patients. Discussion: Although limited by the retrospective nature of the study, this is one of the few cancer reports from Northern Italy showing results over 10 years, which may in our view, have an impact on decision-making processes for multidisciplinary teams dedicated to the care of gastric cancer patients.

Methylation Analysis of Urinary Sample in Non-Muscle-Invasive Bladder Carcinoma: Frequency and Management of Invalid Result.

BACKGROUND: Numerous studies showed that methylation analysis represents a newly developed urinary marker based on DNA methylation changes in a panel of genomic biomarkers and it could represent a valid tool in terms of the diagnosis and prediction of high-grade urothelial carcinoma recurrences. One of the limits of the use of this new molecular method during a follow-up is represented by the number of invalid tests in routine practice. METHOD: A total of 782 patients with a diagnosis of non-muscle-invasive high-grade carcinoma (NMIBC) was studied. The Bladder EpiCheck test (BE) was performed together with cytology in all cases within 1 year after the end of treatment. In 402 patients, the urinary samples were voided urine (UV), while, in 380 cases, the samples were collected after bladder washing (IU). For all the patients with invalid BE results, a second BE test was performed following the instructions for use that indicated the test should be repeated with a new urinary sample in the case of an invalid result. RESULTS: Analyzing the two different groups (UV and IU), we found the invalid BE results seemed to be not related to urinary samples (p = 0.13 Fisher's exact test), suggesting that the collection method was not relevant in order to reduce the number of invalid tests. CONCLUSIONS: In the follow-up for NMIBC, for patients for whom a BE test is planned, a combined approach of cytology and a methylation test is recommended in order to repeat the BE test with an invalid result only in those cases with a cytological diagnosis of atypical urothelial cells (AUC) suspicious for high-grade urothelial carcinoma (SHGUC) and high-grade urothelial carcinoma (HGUC).

Giant Invasive Intradural Extramedullary Lumbar Schwannoma: A Case Report and Literature Review.

Schwannomas are benign nerve sheath tumors that arise from Schwann cells, which are responsible for producing the myelin sheath that surrounds nerves. They are typically slow-growing and can occur in various locations in the body, including the lumbar region of the spine. We present a case of giant invasive intradural extramedullary schwannoma managed with posterior lumbar interbody fusion (PLIF) and laminectomy with excellent results. A 58-year-old man presented with lower back pain radiating to the right leg for six months. He had no history of trauma or systemic disease. Lumbosacral magnetic resonance imaging (MRI) showed a well-defined mass at the L3-L4 level compressing the right nerve root. The patient was managed with L3-L4-L5 transpedicular fixation and right-side laminectomy L3-L4 for resection of the tumor. Histopathological examination confirmed the diagnosis of schwannoma. The patient had a favorable postoperative recovery and experienced a resolution of symptoms. Lumbar schwannomas are rare they can cause significant symptoms and require appropriate diagnosis and management. Microsurgery is the preferred treatment, and endoscopic microsurgery is the most promising technique.

The effect of recreational cannabis legalization and commercialization on substance use, mental health, and injury: a systematic review.

OBJECTIVE: To determine the effect of recreational cannabis legalization (RCL) and/or recreational cannabis commercialization (RCC) on emergency department (ED) visits, hospitalizations, and deaths due to substance use, injury, and mental health among those aged 11 years and older. METHODS: A systematic review of six electronic databases up to February 1, 2023. Original, peer-reviewed articles with interrupted time series or before and after designs were included. Four independent reviewers screened articles and assessed risk of bias. Outcomes with 'critical' risk of bias were excluded. Protocol registered on PROSPERO (# CRD42021265183). RESULTS: After screening and risk of bias assessment, 29 studies were included which examined ED visits or hospitalizations for cannabis use or alcohol (N = 10), opioid mortality (N = 3), motor vehicle fatalities or injury (N = 11), and intentional injury/mental health (N = 5). Rates or number of cannabis-related hospitalizations increased after RCL in Canada and the USA. Immediate increases in rates of cannabis-related ED visits were found after both RCL and RCC in Canada. Rates of traffic fatalities increased after RCL and RCC in certain jurisdictions in the USA. CONCLUSIONS: RCL was associated with increased rates of cannabis-related hospitalizations. RCL and/or RCC was associated with increased rates of cannabis-related ED visits, consistently shown across sex and age groups. The effect on fatal motor vehicle incidents was mixed, with observed increases found after RCL and/or RCC. The effect of RCL or RCC on opioids, alcohol, intentional injury, and mental health is not clear. These results inform population health initiatives and international jurisdictions considering RCL implementation.

Gene expression of pregnancy-associated glycoproteins-1 (PAG-1), interferon-tau (IFNt) and interferon stimulated genes (ISGs) as diagnostic and prognostic markers of maternal-fetal cellular interaction in buffalo cows.

The aim of this study was to determine the presence of Pregnancy-associated glycoprotein -1 (PAG-1) mRNA expression in the maternal circulation of pregnant buffaloes during the early stage of pregnancy. Contemporaneously, the mRNA expression levels of Interferon-tau (IFNt) and some Interferon stimulated genes (ISGs) (interferon stimulated gene 15 ubiquitin-like modifier interferon, ISG15; Mixoviruses resistance 1 and 2, MX1 and MX2; 2',5'-oligoadenylate synthase 1,OAS1) were evaluated in order to expand our knowledge of the molecular processes involved in the early stages of pregnancy and to identify potential biomarkers of maternal-fetal cellular interaction in buffalo. The study was conducted on 38 synchronized and artificially inseminated buffalo cows (d 0), divided ex post into 3 groups: Pregnant (n = 17), Non-pregnant (n = 15) and Embryo mortality (n = 6). Blood samples were collected on d 14, 19, 28 and 40 after artificial insemination (AI) for peripheral blood mononuclear cells (PBMCs) isolation. Expression levels of mRNA of PAG-1, IFNt, ISG15. MX1, MX2 and OAS1 were measured using RT-qPCR. No significant changes were observed in IFNt and PAG gene expressions between groups, while significant differences (p < 0.001) were found for ISG15, MX1, MX2, and OAS1. Pairwise comparisons revealed that the differences between groups occurred on days 19 and 28 post-AI. ISG15 proved to have the best diagnostic performance for distinguishing between pregnant animals and animals that experienced embryo mortality with the ROC analysis. According to the results of the univariate analyses, day 19 was identified as the most indicative to discriminate between groups while the most reliable genes for this differentiation were ISG15, MX1 and MX2. MX2 proved to be the best gene for discriminating pregnant buffaloes using the discriminant analysis, while MX1 was the gene that best predicted embryo mortality. Our results showed that among PAG-1, IFNt and ISGs expression as diagnostic and prognostic markers of maternal-fetal cellular interaction in buffalo cows, ISGs proved to be the best peripheral biomarkers for predicting pregnancy and embryonic mortality during the peri-implantation period. These insights into the mechanisms behind maternal-fetal interaction and the development of a method for the early detection of embryo distress may enable us to implement effective strategies to support embryo survival.

Dural arteriovenous fistula of the torcular herophili presenting with hydrocephalus and venous congestion in an 8-month-old child: A case report.

Dural arteriovenous fistulas (DAVFs) are direct communication between the dural arterial and venous systems. They are more common in adults. In children, they are relatively rare. Hydrocephalus is a common problem in pediatrics with a variety of causes. However, very few cases of hydrocephalus as a complication of DAVF have been reported in the literature. This case describes an 8-month-old male child with a large DAVF at the torcular herophili who presented with regression of milestones and hydrocephalus. Magnetic resonance imaging (MRI) on admission showed triventricular hydrocephalus and a massively dilated torcular with a compressed fourth ventricle. Angiography confirmed the presence of a DAVF at the torcula with arterial feeders from the posterior circulation. Endovascular embolization was performed with >80% embolization of the fistula with no complications. Control MRI immediately postoperative was acceptable. No cerebrospinal fluid (CSF) diversion was performed. At a 3-month follow-up, the child had attained all developmental milestones for age. MRI showed normal CSF dynamics and a further reduction in the size of the torcula. Despite being rare, DAVFs should be considered as a possible cause of pediatric hydrocephalus, and treating them can lead to a resolution of the mechanisms inducing hydrocephalus. CSF shunting should be reserved for those cases with persistent hydrocephalus and raised intracranial pressure despite endovascular treatment.

Repeat discectomy for recurrent same level disc herniation: A literature review of the past 5 years.

Background: Recurrent disc herniations remain a challenge in spinal surgery. Although some authors recommend a repeat discectomy, others offer more invasive secondary fusions. Here, we reviewed the literature (2017-2022) regarding the safety/efficacy of treating recurrent disc herniations with repeated discectomy alone. Methods: Our literature search of recurrent lumbar disc herniations included; Medline, PubMed, Google scholar, and the Cochrane database. We focused on the types of discectomy performed, perioperative morbidity, costs, length of surgery, pain scores, and incidence of secondary dural tears. Results: We identified 769 cases that included 126 microdiscectomies, and 643 endoscopic discectomies. Rates of disc recurrence ranged from 1% to 25% with accompanying secondary durotomy varying from 2% to 15%. In addition, operative times were relatively short, ranging from 29.2 min to 125 min, with a relatively small average estimated blood loss (i.e., minimal to maximally 150 mls). Conclusion: Repeated discectomy was the most commonly performed treatment for same-level recurrent disc herniations. Despite minimal intraoperative blood loss and short operating times, there was a significant risk of durotomy. Notably, patients must be informed that more extensive bone removal for treating recurrent disc increases the risk for instability warranting subsequent fusion.

Development of a 3D Printed Brain Model with Vasculature for Neurosurgical Procedure Visualisation and Training.

BACKGROUND: Simulation-based techniques using three-dimensional models are gaining popularity in neurosurgical training. Most pre-existing models are expensive, so we felt a need to develop a real-life model using 3D printing technology to train in endoscopic third ventriculostomy. METHODS: The brain model was made using a 3D-printed resin mold from patient-specific MRI data. The mold was filled with silicone Ecoflex™ 00-10 and mixed with Silc Pig® pigment additives to replicate the color and consistency of brain tissue. The dura mater was made from quick-drying silicone paste admixed with gray dye. The blood vessels were made from a silicone 3D-printed mold based on magnetic resonance imaging. Liquid containing paprika oleoresin dye was used to simulate blood and was pumped through the vessels to simulate pulsatile motion. RESULTS: Seven residents and eight senior neurosurgeons were recruited to test our model. The participants reported that the size and anatomy of the elements were very similar to real structures. The model was helpful for training neuroendoscopic 3D perception and navigation. CONCLUSIONS: We developed an endoscopic third ventriculostomy training model using 3D printing technology that provides anatomical precision and a realistic simulation. We hope our model can provide an indispensable tool for young neurosurgeons to gain operative experience without exposing patients to risk.

Generation of an iPSC line from skin fibroblasts of a patient with Joubert syndrome carrying the homozygous loss of function variant c.787dupC in the AHI1 gene.

We produced an iPSC line from a patient with Joubert syndrome carrying the homozygous c.787dupC variant in the AHI1 gene. The iPSC line was obtained by reprogramming skin fibroblasts, mycoplasma-free, using Sendai-virus-based technique. Characterization of iPSCs showed the same Short Tandem Repeats profile than fibroblasts, normal karyotype, expression of staminal markers (OCT4, SOX2, SSEA4 and NANOG) and ability to differentiate into three germ layers in vitro.

Degenerative Grade 3 Spondylolisthesis Management: A Case Report and Literature Review.

Degenerative spine disorders are very common in the aging population. Degenerative spondylolisthesis is a relatively uncommon cause of chronic back pain in these patients. We present a case of high-grade spondylolisthesis managed with posterior lumbar interbody fusion (PLIF) and reduction of the listhesis with excellent results. A 56-year-old woman presented with chronic lower back pain managed as an outpatient for over 5 months with no relief. She had no history of trauma or risk factors for malignancy. Lumbosacral CT showed Meyerding grade 3 anterolisthesis of the fifth lumbar vertebra with complete L5-S1 disc collapse and bilateral spondylolysis. An MRI confirmed the findings. There was no spinal canal stenosis. The patient was managed with L4-L5-S1 transpedicular fixation and L5-S1 interbody cage with reduction of the listhesis. The patient had an incidental intraoperative dural tear which was repaired primarily and a wound drain was kept for 5 days without complications. The patient was ambulating by day 5 and was discharged without complications on day 10. Degenerative spondylolisthesis can cause chronic back pain with or without a history of trauma. Although no specific clinical features exist for this condition, it should be suspected in elderly patients even in the absence of a history of trauma. Surgical management in high-grade spondylolisthesis is indicated with interbody fixation and reduction.

Sjögren syndrome successfully treated with oxygen-ozone auto-hemotherapy (O2-O3-AHT). a case report.

OBJECTIVE: Sjögren syndrome (SS) is an autoimmune disorder, affecting about 16,000 individuals in Italy, yet lacking a standardized therapy protocol and a plain inclusion in the reimbursed healthcare services. This raises many controversial issues about how managing the SS patient, to relief pain and discomfort and improve patients' health and social life. The ozone therapy resulted successful in previous reports, and therefore, it was used in this case report. CASE PRESENTATION: A 69-years old female outpatient, showing positivity to Schirmer's test, was previously diagnosed as a primary Sjögren syndrome, who later developed an autoimmune thyroiditis and showed the presence of rheumatoid factors. The patient suffered from a marked ocular dryness, subsequently to a purported endothelitis, alongside with fatigue and pain. Laboratory tests showed a positive ANA 1:320 in a speckled pattern with negative anti-SSA and anti-SSB tests. From December 2020 to January 2021 she underwent 2 routes of three sessions of oxygen-ozone autohemotherapy (O2-O3 AHT), as described below and improved, with only 2 sessions, her symptomatology and clinical outcome, as ocular dryness, fatigue and pain, rapidly disappeared. CONCLUSIONS: The use of ozone in the therapy of SS is a straightforward, affordable and feasible approach to treat primary Sjögren syndrome without significant side effects.

Surgical Management of Lumbar Hardware Failure Due to Recurrent Postoperative Spondylodiscitis: Case Report.

Spondylodiscitis is a rare bacterial infection of the vertebrae and intervertebral discs that causes inflammation and follows a destructive course. When conservative management fails, surgical management requires immediate debridement of the infective focus, with decompression and stabilization through a ventral approach. The most frequently involved locations are the lumbar spine (58%), thoracic (30%), and cervical (11%) regions. Gram-positive organisms such as Staphylococcus aureus and Streptococcus species are the most commonly isolated organisms (67% and 24%, respectively). Pathophysiologically, infectious spondylodiscitis begins in the anterior portion of the vertebral body, due to its rich vascular supply, and then spreads to the rest of the vertebral body and along the medullary spaces. In this study, we report the management of recurrent lumbar postoperative spondylodiscitis with transforaminal lumbar interbody fusion (TLIF) hardware failure in a 62-year-old female.

Three-Dimensional Plastic Modeling on Bone Frames for Cost-Effective Neuroanatomy Teaching.

Cadaveric models remain an essential part of medical training across all specialties. Due to their scarcity, high costs, and possible health hazards, there is a need for more accessible and affordable alternatives, especially in low-resource settings. We introduce cost-effective and easily replicable three-dimensional (3D) printed models to help democratize access to hands-on neuroanatomy education. Silicone-based glue is applied on the surface of a 3D-printed or cadaveric bone frame. Using plastiline on a 3 mm 3D acrylonitrile butadiene styrene pen, the desired anatomical structure is printed on the bone frame. A heat gun is used to smoothen the plastic edges. The structure can then be painted according to its appearance in the real anatomy. Using this technique, we successfully generated a variety of anatomical models to study the cerebrovascular anatomy, the course of the cranial nerves in relation to the skull base, and extracranial structures including the spine. Procurement and conservation of cadaveric specimens can be cumbersome. Our model may be an affordable and easily replicable approach to bridging the gap in anatomy education between low- and high-resource facilities.

Apparent autistic traits in transgender people: a prospective study of the impact of gender-affirming hormonal treatment.

PURPOSE: We evaluated differences in Autism Spectrum Quotient (AQ) scores between a sample of hormone-naïve transgender and cisgender people and the impact of gender-affirming hormonal treatment (GAHT) on AQ scores across time. Furthermore, we assessed alexithymia and social anxiety as possible mediators of changes in AQ scores. METHODS: A cross-sectional comparison between cisgender and transgender people before GAHT and a prospective study on the effects of GAHT over time were performed. Transgender and cisgender people completed several psychometric tests. A total sample of 789 persons (n = 229 cismen; n = 172 ciswomen; n = 206 transmen; n = 182 transwomen) referring to the Florence and Rome Gender Clinics between 2018 and 2020 was enrolled. Of these, 62 participants referring to the Florence Gender Clinic were evaluated in a prospective study at baseline and 12 months after GAHT. RESULTS: Groups showed significant differences in terms of autistic traits: ciswomen showed lower scores of AQ, while cismen reported higher scores of AQ than all other groups. Transgender individuals showed significant higher levels of Gender Dysphoria (GD), body uneasiness, alexithymia and social anxiety, compared to cisgender ones. No significant differences in general psychopathology were found between groups. Across time, transmen and transwomen showed a significant reduction in AQ scores. The decrease in alexithymia and social anxiety after GAHT did not predict the change in AQ scores. CONCLUSIONS: The autistic traits in our sample may represent an epiphenomenon of GD rather than being part of an Autism Spectrum Disorder (ASD) condition, since they significantly decreased after 12 months of GAHT.

Microsurgical Wiltse Paraspinal Approach Using a Low-Budget Exoscope.

Access to microneurosurgical care in low- and middle-income countries remains limited mainly due to a lack of equipment. High purchasing and maintenance costs hinder the use of operating microscopes in low-resource facilities. The authors present an improved version of their previously introduced low-cost exoscope to achieve high magnification and illumination in low-resource environments. The setup included a 48-megapixel two-dimensional digital microscope camera, a wide field C-mount lens, ring light, and a two-link cantilever with a screw terminal. The surgical field was projected to a portable 17.3-inch 2K resolution monitor. Ten patients underwent exoscope-assisted transforaminal lumbar interbody fusion via the Wiltse paraspinal approach. The simple construction allowed a fast and intuitive preoperative setup. The in-plane switching type display provided a clear and bright image regardless of the viewing angle. The two-link arm of the cantilever allowed smooth positioning of the camera, overcoming the cumbersome up and down movements needed to zoom in and out with the previous prototype. Industrial microscope cameras are effective low-budget alternatives to conventional operating microscopes in lumbar microdiscectomy. The improved system is superior compared to the authors' previous prototype with regard to affordability, image quality, and adjustability of position and angle.

First-trimester prediction of gestational hypertension through the bioelectrical impedance analysis of the body composition.

OBJECTIVE: Obesity is a risk factor for the development of gestational hypertension, with important consequences for both the mother and fetus. This prospective observational study aims to propose an early prediction model of hypertensive disorders in pregnancy among obese women, through the bioelectrical impedance analysis (BIA) at the first trimester, thus allowing early recognition of obese women that are at risk to develop gestational hypertension, in order to target preventive interventions. PATIENTS AND METHODS: Singleton obese women (BMI ≥ 30 kg/m2) between the 9th and 12th week of pregnancy were included in the study. The exclusion criteria were chronic diseases, like type 2 diabetes mellitus, hypertension, and other medical pre-existing conditions. Eligible women were followed up at 20, 28, and 36 weeks of gestation by measuring blood pressure, weight, and body composition with the use of the BIA. The diagnosis of gestational hypertension was made after the 20th week of gestation. Pregnancy and perinatal outcomes were then recorded. RESULTS: Of the 479 women included in the study, 85 (17.7%) developed gestational hypertension; the remaining 394 (82.3%) resulted to be normotensive. A higher rate of nulliparous women was found in the hypertensive group (50.6% vs. 37.6%, p = 0.02), together with a higher rate of induction of labor (55.3% vs. 40.9%, p = 0.02) and of small for gestational age (SGA) newborns (12.9% vs. 6.9%, p = 0.03). Significant differences emerged in the body composition between the two groups already from the first trimester, indeed women developing gestational hypertension showed elevated values of Total body Mass, FM, FFM, TBW (p < 0.02), and of leg's FM, FFM (p < 0.006). At the multivariate logistics regression, the risk of developing gestational hypertension resulted higher in women with elevated total body water levels in the first trimester (OR 1.10 95% CI 1.04 -1.92). CONCLUSIONS: The BIA is a rapid, easy, non-invasive, and inexpensive tool to evaluate the body composition of obese pregnant women. It represents a promising predictor of hypertensive disorders in pregnancy, which allows an early identification of the patients at risk of developing gestational hypertension, thus opening a window of opportunity for strictly monitoring and target preventive intervention.

Determination of ion recombination and polarity effects for the PTW Advanced Markus ionization chamber in synchrotron based scanned proton and carbon ion beams.

The aim of this work was the investigation of the ion recombination and polarity factors (ksat ad kpol) for a PTW Advanced Markus ionization chamber exposed to proton and carbon ion beams at the Centro Nazionale di Adroterapia Oncologica. Measurements with protons were specifically dedicated for ocular treatments, in the low energy range and for small, collimated scanning fields. For both protons and carbon ions, several measurements were performed by delivering a 2D single energy layer of 3x3 cm2 and homogeneous, biologically-optimized SOBPs. Data were collected at different depths in water, by varying the voltage values of the ionization chamber and for two different dose rates (the nominal one and one reduced to 20% of it). The ksat-values were determined from extrapolation of the saturation curves. Furthermore kpol-values were calculated using the recommendations from the International Atomic Energy Agency (IAEA) Technical Report Series (TRS)-398 Code of Practice. Results showed that the Advanced Markus performs optimally in this clinical scenario characterized by small treatment volumes and high dose gradients although for both particle types, but particularly for carbon ions, a charge multiplication effect up to 1.7% occurs at voltage higher than 150 V. For protons, both the ion recombination and polarity corrections were always smaller than 0.3%, for all the analysed cases and adopted dose rates, so not affecting the dosimetric measurements for clinical routine. For carbon ions the polarity effect can be neglected while ion recombination has to be carefully calculated and cannot be neglected since corrections even higher than 1% can be found, especially at high LET measuring points.

New insights into real-time detection of tephra grainsize, settling velocity and sedimentation rate.

Characterizing the size and settling velocity of pyroclastic fragments injected into the atmosphere during volcanic eruptions (i.e., tephra) is crucial to the forecasting of plume and cloud dispersal. Optical disdrometers have been integrated into volcano monitoring networks worldwide in order to best constrain these parameters in real time. Nonetheless, their accuracy during tephra fallout still needs to be assessed. A significant complication is the occurrence of particle aggregates that modify size and velocity distributions of falling tephra. We made the first use of the Thies Clima Laser Precipitation Monitor (LPM) for tephra-fallout detection at Sakurajima volcano (Japan), which is characterized by a lower size detection window with respect to more commonly used disdrometers (e.g., Parsivel2) and can more easily distinguish different falling objects. For the first time, individual particles have been distinguished from most aggregates based on disdrometer data, with the potential to provide useful grain-size information in real time. In case of negligible aggregation, LPM and collected sample-based estimates are in agreement for both grain-size and sedimentation rate. In case of significant aggregation, particle shape analyses and a dedicated drag equation are used to filter out aggregates from LPM data that also provide good agreement with collected tephra samples.