Dandy-Walker malformation and variants: clinical features and associated anomalies in 28 affected children-a single retrospective study and a review of the literature

OBJECTIVE

To investigate the clinical characteristics, the neuroimaging features and associated anomalies observed in children affected by Dandy-Walker malformations (DWM) and variants (DWV) in a single tertiary hospital in Catania and compare our data to their existent in the literature.

METHODS

A retrospective case series using the medical records has been performed on 28 children diagnosed with DWM and DWV admitted to a single tertiary section of Pediatric Neurology, Department of Catania, Italy from January 2005 to January 2021. We reviewed the neuroimaging using the new diagnostic criteria of Klein et al. RESULTS: Associated anomalies were frequently reported. Among these, hydrocephalus was found in 13/28 (48%), and hydrocephalus plus corpus callosum anomalies in three children (10%). We described corpus callosum, cardiac and genitourinary anomalies in 2/28 (7%), 3/28 (10%), and 3/28 (10%), respectively. The most common clinical features were the developmental delay and epilepsy observed in 19/28 (67%) and in 9/28 (32%) of the cases. The first exam at the diagnosis was MRI in 17/28 patients, followed by transfontanellar ultrasound in 5/28, computed tomography in 4/28 and prenatal ultrasound in 2/28. To note, a child with DWM was affected by Down syndrome and one by congenital disorders of N-linked glycosylation (CDG-IId).

CONCLUSIONS

Children with DWV were more commonly observed than children with DWM. Hydrocephalus is an anomaly, frequently and equally reported in both DWM and DMV. Perinatal complications were frequent adverse events with severe respiratory distress and need for cardiopulmonary resuscitation. Cognitive involvement and epilepsy were the most common comorbidities. Single DWV is associated with a better developmental outcome.

[Quantitative imaging in nephrology: limits and potentials of elastosonography]

Chronic kidney disease is characterized by increasingly amplified fibrotic processes regardless of etiology. The severity of renal fibrosis seems to correlate with an increased risk of end-stage renal disease; therefore, monitoring of renal fibrosis over time may play an important role in the follow-up of both focal and diffuse renal diseases and in evaluating the response to treatments. Renal biopsy is the only method capable of providing objective and comparable information on the extent of fibrosis, but it is not suitable for outpatient monitoring of chronic kidney disease due to its invasiveness. Elastosonography is an innovative and non-invasive ultrasound method that allows the measurement of tissue elasticity through the transmission of mechanical waves and the measurement of their propagation speed. Although some authors have demonstrated the usefulness of elastosonographic techniques for the quantification of liver fibrosis, few studies have investigated the applications of elastosonography in renal pathology. Furthermore, the depth of native kidneys, the high anisotropy of the renal tissue, and the possibility of examining only a small region of interest currently limit its spread in clinical practice. The aim of this review is to examine the physical principles of elastosonography and to review the latest evidence about the possible applications of the ARFI (acoustic radiation force impulse) technique in the study of kidney diseases.

OP0095 SINGLE-CELL RNA SEQUENCING REVEALS POTENT ANTI-INFLAMMATORY AND ANTIFIBROTIC ACTIVITIES OF DIMETHYL-ALPHA-KETOGLUTARATE ON EXPLANTED SKIN FROM PATIENTS WITH SYSTEMIC SCLEROSIS

Background

Activated fibroblasts are the main drivers of skin fibrosis in SSc. We have recently identified dimethyl alpha-ketoglutarate (dm-aKG) as a potential repressor of myofibroblast differentiation and profibrotic activity in cultured skin fibroblasts.

Objectives

To further analyse the clinical translation of our findings by investigating the antifibrotic capacity of dm-aKG on explanted skin biopsies from SSc patients.

Methods

We cultured forearm punch skin biopsies from SSc patients (n=10) for 24h ex vivo in the presence/absence of 6 mM dm-aKG. Thereafter, skin biopsies (n=4) were dissociated into single cells using a combined mechanical-enzymatic dissociation protocol, followed by single cell (sc)RNA-seq library preparation (10x Genomics) and sequencing (Illumina, NovaSeq6000, 50,000 reads/cell). We mapped the scRNA-seq reads to the reference genome GRCh38.p13 and analysed the data with R/Bioconductor tools. We deconvoluted cell types in bulk skin transcriptomes from SSc cohorts (GSE: 45485, 59785, 9285, 32413) using human skin scRNA-seq data1. The secretion of IL-6, procollagen-1, PRO-C1 (N-terminal type I collagen pro-peptide), C1M (MMP-degradation fragment of type I collagen), and fibronectin (FBN-C) from cultured skin (n=10) was measured in supernatants by ELISA. We analysed gene and protein expression in TGFβ-activated healthy and SSc dermal fibroblasts (DF, n=10) treated or not with dm-aKG using qPCR, Western blot and ELISA. Contractile properties of DF were assessed by gel contraction assay. Traction forces generated by DF were determined by reference-free traction force microscopy.

Results

Dissociated cultured SSc skin exhibited comparable cell yield and viability in the presence (20,203; 89%) and absence (25,280; 93%) of dm-aKG, respectively. scRNA-seq skin analysis included 20,869 high quality single cell profiles segregating into 10 distinct skin cell populations (Figure 1A). This analysis demonstrated decreased proportion of fibroblasts and increased proportion of keratinocytes in dm-aKG treated skin (p<0.05; Figure 1B). Among skin cell types, skin fibroblasts exhibited the largest amount of differentially expressed genes upon dm-aKG treatment (44%, n=779, x-fold>0.5, FDR<0.05), suggesting that these cells are key targets of dm-aKG therapy in SSc skin. We identified inflammatory/cytokine signalling (hub genes IL6, STAT1) and extracellular matrix (ECM) organization (hub genes MMP1, ITGB3) as top downregulated biological processes in fibroblasts in dm-aKG treated SSc skin (Figure 1C), coinciding with a decreased abundance of proinflammatory skin fibroblast subpopulation. Specifically, these cells were identified as the main source of IL6 (Figure 1D) and were enriched in SSc skin as revealed by deconvolution analysis of skin transcriptomes. Furthermore, dm-aKG reduced the secretion of IL-6, procollagen-1 and C1M, but not pro-C1 and FBN-C, from cultured skin explants. In cultured DF, dm-aKG blocked the inflammatory (IL-6, pSTAT3), profibrotic (aSMA, Fibronectin, Procollagen-1, Pro-C1) and contractile activities, and significantly diminished traction forces exerted by DF on the matrix substrate.

Figure 1.

scRNA-seq – comparison of untreated and dm-aKG treated paired skin biopsies. (A) UMAP plot with annotated skin cells, (B) differential abundance of main skin cell types, (C) volcano plot of DE genes with top downregulated gene ontology (GO) pathways in dm-aKG treated skin fibroblasts, (D) IL6 expression in untreated (blue) and treated (pink) skin fibroblasts.

Conclusion

Dm-aKG broadly interferes with inflammatory and ECM organizational activities of skin fibroblasts in culture and in explanted skin from SSc patients. These results confirm that dm-aKG might represent a potential new therapeutic approach for efficient targeting of skin inflammation and fibrosis in SSc.

References

[1]He H et al. J Allergy Clin Immunol 2020

Acknowledgements

This work was supported by a research grant from FOREUM Foundation for Research in Rheumatology and University Medical Centre Ljubljana.

Disclosure of Interests

Blaž Burja: None declared, Dominique Paul: None declared, Reto Gerber: None declared, Sam G. Edalat: None declared, Muriel Elhai Speakers bureau: BMS, Elena Pachera: None declared, Rahel S. Zingg: None declared, Francesca Michela Pramotton: None declared, Sofie Falkenløve Madsen: None declared, Kristina Buerki: None declared, Giampietro Costanza: None declared, Michael Whitfield: None declared, Anne-Christine Bay-Jensen: None declared, Snežna Sodin-Šemrl: None declared, Matija Tomsic: None declared, Gabriela Kania: None declared, Hubert Rehrauer: None declared, Oliver Distler Speakers bureau: Bayer, Boehringer Ingelheim, Janssen, Medscape, Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, 4P Science, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Grant/research support from: Kymera, Mitsubishi Tanabe, Boehringer Ingelheim, Ziga Rotar: None declared, Mark Robinson: None declared, Katja Lakota: None declared, Mojca Frank Bertoncelj: None declared.

[Urinary tract infections in nephrology: antibiotic therapy in the era of antibiotic resistance]

Urinary tract infections (UTIs) are an emerging health problem. Kidney patients with UTI are at increased risk of antimicrobials resistance (AMR) and bad prognosis. In the nephrological setting, optimizing the management of UTIs is certainly a challenge, but it is indispensable for a favorable clinical outcome and in fighting AMR. When UTIs caused by multidrug-resistant germs are suspected, it is necessary to initiate empirical antibiotic therapy timely, pending microbiological study and bacterial sensitivity. The empirical choice of antibiotic must be based on: guidelines, resistance rates recorded in the region, and knowledge of pharmacokinetic and pharmacodynamic characteristics of the drug, in order to maximize efficacy, reduce adverse effects and minimize AMR development. Recently, the clinical use of old drugs such as colistin has increased, due to the limited circulation of resistant bacterial strains. On the other hand, ceftolozane/tazobactam, ceftazidime/avibactam, cefiderocol, imipenem/cilastatin/relebactam and meropenem-vaborbactam are very promising new antibiotics. Ongoing clinical studies will be able to determine the place for these interesting molecules in the treatment of infections and in fighting AMR.

[SGLT2 inhibitors, beyond glucose-lowering effect: impact on nephrology clinical practice]

Epidemiological data show an increasing diffusion of diabetes mellitus worldwide. In the diabetic subject, the risk of onset of chronic kidney disease (CKD) and its progression to the terminal stage remain high, despite current prevention and treatment measures. Although SGLT2 inhibitors have been approved as blood glucose lowering drugs, they have shown unexpected and surprising cardioprotective and nephroprotective efficacy. The multiple underlying mechanisms of action are independent and go beyond glycemic lowering. Hence, it has been speculated to extend the use of these drugs also to subjects with advanced stages of CKD, who were initially excluded because of the expected limited glucose-lowering effect. Non-diabetic patients could also benefit from the favorable effects of SGLT2 inhibitors: subjects with renal diseases with different etiologies, heart failure, high risk or full-blown cardiovascular disease. In addition, these drugs have a good safety profile, but several post-marketing adverse event have been reported. The ongoing clinical trials will provide clearer information on efficacy, strength and safety of these molecules. The purpose of this review is to analyze the available evidence and future prospects of SGLT2 inhibitors, which could be widely used in nephrology clinical practice.

[Ultrasonography for diagnosis and management of nephrolithiasis: state of the art and new perspectives]

The correct management of patients with kidney stones is a crucial issue for nephrologists. In recent years, the incidence and prevalence rates of nephrolithiasis have maintained a growing trend worldwide, showing a strong correlation with other systemic disease such as diabetes mellitus, hypertension, obesity, metabolic syndrome and chronic kidney disease. International guidelines indicate computed tomography as the first choice for all adult patients with suspected acute symptoms for obstructive nephrolithiasis. Intravenous pyelogram is more useful in the follow-up of patients with relapsing nephrolithiasis and known stone composition, while the high costs and the long image acquisition times limit the routine use of magnetic resonance. Recent innovative tools have improved the accuracy of kidney stone localization and measuring with B-Mode and color Doppler imaging, thereby reducing the gap between ultrasonography and computer tomography. The aim of this review is to report the latest evidence on risk factors and on the pathophysiology of nephrolithiasis, and to compare the utility of the available imaging techniques in the management of patients with kidney stones, focusing on the role of ultrasonography and the present and future strategies to improve its accuracy.

Relationship Between Carotid Atherosclerosis and Pulse Pressure with Renal Hemodynamics in Hypertensive Patients

BACKGROUND

Structural atherosclerotic damage, arterial stiffness, pulse pressure (PP), and renal hemodynamics may interact and influence each other. Renal resistance index (RRI) appears as a good indicator of systemic vascular changes. The aim of our study was to assess the independent relationships of carotid intima-media thickness (cIMT), aortic pulse wave velocity (aPWV), and peripheral PP with RRI in hypertensives with various degrees of renal function.

METHODS

We enrolled 463 hypertensive patients (30-70 years) with normal renal function (group 0; n = 280) and with chronic kidney disease (groups I-V; n = 183). All subjects underwent ultrasonographic examination of intrarenal and carotid vasculature, as well as a 24-h ambulatory blood pressure monitoring.

RESULTS

A statistically significant difference in RRI, cIMT, aPWV, and clinic PP was observed in the different 6 groups (all P < 0.001), even after adjustment for age. RRI correlated with cIMT (r = 0.460, P < 0.001), aPWV (r = 0.386, P < 0.001), clinic PP (r = 0.279, P < 0.001), and 24-h PP (r = 0.229, P < 0.001) in the entire study population. These correlations were similar in subjects with and without renal dysfunction. In the overall study population, the association between RRI, cIMT, and clinic PP remained statistically significant even after adjustment for various confounding factors, whereas the relationship between RRI and aPWV was lost in multivariate analysis.

CONCLUSIONS

cIMT and clinic PP rather than directly aPWV are associated with intrarenal hemodynamics. Our results confirm that in hypertensives RRI not only detects derangement of intrarenal circulation but may also be considered as a sensor of systemic vascular changes, independently of level of renal function.

Additional constraints in adsorption-desorption kinetics

In this work, the adsorption-desorption kinetic in the framework of the lattice gas model is analyzed. The transition probabilities are written as an expansion of the occupation configurations. Due to that, the detail balance principle determine half of the adsorption A{i} and desorption D{i} coefficients, consequently, different functional relations between them are proposed. Introducing additional constrains, it is demonstrated that when those coefficients are linearly related through a parameter gamma , there are values of lateral interaction V , that lead to anomalous behavior in the adsorption isotherms, the sticking coefficient and the thermal programmed desorption spectra. Diagrams for the allowed values of V and gamma are also shown. Alternatively, a more reliable formulation for the adsorption desorption kinetic based on the transition state theory is introduced. In such way the equilibrium and non equilibrium observables do not present anomalous or inconsistent behavior.

Ageing, lifestyle modifications, and cardiovascular disease in developing countries

Developing countries face the double menace of still prevalent infectious diseases and increasing cardiovascular disease (CVD) with epidemic proportions in the near future, linked to demographic changes (expansion and ageing), and to urbanisation and lifestyle modifications. It is estimated that the elderly population will increase globally (over 80% during the next 25 years), with a large share of this rise in the developing world because of expanding populations. Increasing longevity prolongs the time exposure to risk factors, resulting in a greater probability of CVD. As a paradox, increased longevity due to improved social and economical conditions associated with lifestyle changes in the direction of a rich diet and sedentary habits in the last century, is one of the main contributors to the incremental trend in CVD. The variable increase rate of CVD in different nations may reflect different stages of "epidemiological transition" and it is probable that the relatively slow changes seen in developing populations through the epidemiological transition may occur at an accelerated pace in individuals migrating from nations in need to affluent societies (i.e. Hispanics to the USA, Africans to Europe). Because of restrained economic conditions in the developing world, the greatest gains in controlling the CVD epidemic lies in its prevention. Healthy foods should be widely available and affordable, and healthy dietary practices such as increased consumption of fresh fruits and vegetables, reduced consumption of saturated fat, salt, and simple sugars, may be promoted in all populations. Specific strategies for smoking and overweight control may be regulation of marketed tobacco and unhealthy fast food and promotion of an active lifestyle. Greater longevity and economic progress are accompanied by an increasing burden of CVD and other chronic diseases with an important decrease in quality of life, which should question the benefit of these additional years without quality.

Structures of solid and liquid during melting and solidification of indium

During melting and solidification of polycrystalline indium the structures of the solid and liquid phases were investigated by X-ray diffractometry (XRD) in 1g conditions. The experiments showed that melting is immediately preceded and accompanied by an abnormal increase of vacancy concentration in the solid that enhances the diffusion. At the melting point (T(M)) the lattice planes facing the first formed liquid appear to be [002] and [101]; that is, those planes allocating first and second neighbors around a given atom, with shell radii very close to the mean distance of nearest neighbors in liquid as obtained from the radial distribution function (RDF). On this basis some types of solid-liquid interface (sharp or diffuse) are discussed; the possibility of a sudden texture change in the solid is also considered. On the other hand, the evolution of RDF curve of liquid indium, cooled down through T(M), shows that there are correlations between the structure of the liquid and of the forming solid during solidification. To avoid convective motions in the liquid and to achieve the best experimental conditions, we discuss the possibility of repeating the measurements in microgravity (microg) using thin oxide films as containers. This technique was already successfully tested by one of the investigators in the experiment ES 311 A-B carried out during the mission SPACELAB-1.

Theoretical continuous equation derived from the microscopic dynamics for growing interfaces in quenched media

We present an analytical continuous equation for the Tang and Leschhorn model [Phys. Rev. A 45, R8309 (1992)] derived from their microscopic rules using a regularization procedure. As well in this approach, the nonlinear term (nablah)(2) arises naturally from the microscopic dynamics even if the continuous equation is not the Kardar-Parisi-Zhang equation [Phys. Rev. Lett. 56, 889 (1986)] with quenched noise (QKPZ). Our equation is similar to a QKPZ equation but with multiplicative quenched and thermal noise. The numerical integration of our equation reproduces all the scaling exponents of the directed percolation depinning model.

[Wilson's disease]

Wilson's disease is a rare inherited metabolic disorder usually characterized by liver and/or neurological degeneration. Unlike most genetically transmitted diseases, it rapidly responds to pharmacological treatment in case of early diagnosis and treatment. Often, however, as this disease presents with aspecific symptoms, patients are wrongly diagnosed as psychiatric cases or as having generic chronic liver disease and the true cause of symptoms is only discovered at a much later stage. The authors give a detailed review of the literature with the aim of presenting the most recent research on the main aspects of this disease and offering a practical and simple approach to early diagnosis.

[Insulin resistance in patients with Graves' disease and reduced glucose tolerance. The normalization of fasting insulin secretion in parallel with the restoration of thyroid function]

In order to investigate the nature of impaired glucose tolerance (IGT) in 3 young patients with Graves' disease we have studied their insulin secretion fasting and in response to oral glucose by means of measurement of serum C-peptide. Fasting levels of serum C-peptide of these patients were beyond the range of 15 age-matched normal subjects; the C-peptide/glucose ratio was also significantly higher (p less than 0.001) in the patients than in the controls. Following glucose ingestion serum levels of C-peptide resulted high in the range of normals, with a mean C-peptide/glucose ratio greater than in the controls, but without reaching of statistical significance. To investigate whether the anomaly in fasting insulin secretion of these patients had any correlation with their hyperthyroidism, afterwards we surveyed fasting concentrations of serum C-peptide in parallel with progressive variations of serum free thyroxine and triiodothyronine (FT4 and FT3) and thyrotrophin (TSH) during antithyrotoxic treatment with methimazole. The data of 23 tests on serum FT3 and FT4 levels, carried out during 16-18 months, resulted in significant correlation with contemporaneous measurements of fasting serum C-peptide (p less than 0.001). No significant correlation was found between serum TSH and fasting C-peptide levels. The results suggest that IGT of the patients in this study is not dependent on lacking insulin secretion, but on mild insulin resistance. Such glucose metabolic anomaly appears to be in clear correlation with the degree of hyperthyroidism, even if its pathogenesis remains to be further investigated.

[Correlation between thyroid hypofunction and the presence of circulating antithyroid microsomal antibodies. A phenomenon in the aged, prevalent in women]

The authors evaluated the existence of serum thyroid microsomal antibodies (anti-TMS) and their correlation, if any, with thyroid function in a group of 120 consecutive patients, who seemed clinically worthy to be studied from that point of view, even if they were lacking of a previous laboratory framing. Present study shows a consistent prevalence (81.8%) of anti-TMS concentrations were not related with any hormone parameter of thyroid function. Instead, the prevalence of anti-TMS positive subjects get to 69% in the 39 over-65 aged patients (32 women) of survey, with a concordance between high anti-TMS concentration and hypothyroidism of 87.5% in the subgroup. In these elderly patients circulating anti-TMS and serum TSH were found directly correlated (p less than 0.001), whereas serum FT4 was found in inverse correlation with the same antibodies (p less than 0.01). The consistent share of hypothyroid-aging patients, although mild or subclinical but clearly related with immunological phenomena, cannot be overlooked.

[Behavior of blood ferritin in acute myocardial infarct]

Ferritin (F) is an iron-protein (molecular weight 445.000) present in various organs including the heart. Using the immunoenzymatic method (Ferrizyme Abbott), ferritinemia (Fe) was determined daily in 28 patients with acute myocardial infarction (AMI). A significant rise was revealed, already evident in the first few days 8-9 after with Fe gradually returns to baseline levels. The results have shown that this pattern is not evident in patients with angina, heart failure, valve defects, pericarditis or cor pulmonale and may thus be considered a reliable, if not early, marker of myocardial cytolysis. In those cases studied no correlations were observed between CPK and Fe peak or between these and clinical intensity of AMI.

Serum potassium levels, red-blood-cell potassium and alterations of the repolarization phase of electrocardiography in old subjects

Seventeen elderly patients are described, who showed minor changes in the e.c.g. recovery phase. Serum potassium levels appeared to be normal, but red-blood-cell potassium was found to be more or less markedly reduced. Restoration of the latter to normal values, which followed treatment with potassium salts was also associated with normalization of the e.c.g. pattern. These observations demonstrate that electrolyte disorders, and particularly hypokalaemia, may determine 'minor' alterations of repolarization much more frequently than is usually thought, and that determination of serum potassium levels is not a reliable tool for detecting potassium depletion, which is more accurately reflected by red-blood-cell potassium concentration.