In-situ forming PLGA implants: Towards less toxic solvents

In-situ forming poly(lactic-co-glycolic acid) (PLGA) implants offer a great potential for controlled drug delivery for a variety of applications, e.g. periodontitis treatment. The polymer is dissolved in a water-miscible solvent. The drug is dissolved or dispersed in this solution. Upon contact with aqueous body fluids, the solvent diffuses into the surrounding tissue and water penetrates into the formulation. Consequently, PLGA precipitates, trapping the drug. Often, N-methyl-2-pyrrolidine (NMP) is used as a water-miscible solvent. However, parenteral administration of NMP raises toxicity concerns. The aim of this study was to identify less toxic alternative solvent systems for in-situ forming PLGA implants. Various blends of polyethylene glycol 400 (PEG 400), triethyl citrate (TEC) and ethanol were used to prepare liquid formulations containing PLGA, ibuprofen (as an anti-inflammatory drug) and/or chlorhexidine dihydrochloride (as an antiseptic agent). Implant formation and drug release kinetics were monitored upon exposure to phosphate buffer pH 6.8 at 37 °C. Furthermore, the syringeability of the liquids, antimicrobial activity of the implants, and dynamic changes in the latter's wet mass and pH of the release medium were studied. Importantly, 85:10:5 and 60:30:10 PEG 400:TEC:ethanol blends provided good syringeability and allowed for rapid implant formation. The latter controlled ibuprofen and chlorhexidine release over several weeks and assured efficient antimicrobial activity. Interestingly, fundamental differences were observed concerning the underlying release mechanisms of the two drugs: Ibuprofen was dissolved in the solvent mixtures and partially leached out together with the solvents during implant formation, resulting in relatively pronounced burst effects. In contrast, chlorhexidine dihydrochloride was dispersed in the liquids in the form of tiny particles, which were effectively trapped by precipitating PLGA during implant formation, leading to initial lag-phases for drug release.

Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, genotype-phenotype correlations and common mechanisms

Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (>60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS-like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or "DTRs"). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype-phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population.

Racial disparities in the contemporary utilization and outcomes of left atrial appendage occlusion in the United States

Background

Racial and socioeconomic disparities in the utilization of percutaneous structural heart disease interventions have been described in previous years, reflecting significant gaps. However, it is unclear if increased awareness has created meaningful changes in the utilization of left atrial appendage occlusion (LAAO) in underrepresented populations.

Purpose

We aim to further clarify current practices in the United States and answer questions to help guide further efforts in attenuating health disparities.

Methods

The National Inpatient Sample (NIS) was queried from 2016–2019 to identify all patients >65 years of age diagnosed with atrial fibrillation or atrial flutter who underwent left atrial appendage occlusion (LAAO) using the international classification of diseases, tenth revision clinical modification (ICD-10-CM) codes. We selected this age cutoff to minimize confounding bias from lack of insurance coverage as patients age 65 and older qualify for the Center of Medicare & Medicaid Services. We excluded patients with missing race information. In addition, we confined our analysis to patients of White, Black, and Hispanic ethnicity because the number of other races was insufficient for meaningful analysis. Multivariate linear and logistic regression analysis was performed to compare the odds of procedure utilization, in-hospital mortality, and significant periprocedural complications among study groups.

Results

We identified a total of 14,103,690 patients >65 years of age diagnosed with either atrial fibrillation or atrial flutter. Of those, 53,350 (0.38%) underwent LAAO. The mean age of the sample was 79±7.6 years. Compared to White patients, Black patients had lesser odds of undergoing LAAO when controlling for multiple confounders (AOR = 0.49, 95% CI 0.44–0.55, p<0.001). Among Hispanic patients, there was no statistically significant difference in the odds of undergoing LAAO compared to White patients. There was no statistically significant difference in mortality, vascular complications, non-home discharge, stroke, transient ischemic attack, pericardial tamponade, and length of stay in patients undergoing LAAO among different ethnicities.

Conclusions

Significant disparities, including procedure utilization and patient characteristics prior to the procedure, such as household income, still exist among Black patients compared to White patients undergoing the LAAO in the United States. Nevertheless, adjusted odds of in-hospital outcomes were similar among Black, Hispanic, and White patients. Further research is necessary to identify what mitigation strategies could be effective and what can be changed to close the remaining gap.

Funding Acknowledgement

Type of funding sources: None.

Effect of frailty on in-hospital outcomes after transcatheter mitral valve repair

Background

Mitral regurgitation (MR) is a common valvular disorder associated with significant morbidity and mortality. Transcatheter mitral valve repair (TMVr) is a minimally invasive procedure indicated for the treatment of selected patients with moderate-severe or severe primary MR. Despite a lack of a universal definition, frailty has been associated with poor post-procedural outcomes. Albeit several trials have examined individual prognostic factors in this population, there is a paucity of data regarding the effect of frailty on in-hospital outcomes after TMVr.

Purpose

To further elucidate the association of frailty with in-hospital outcomes in patients undergoing TMVr.

Methods

The national inpatient sample (NIS) database, which is part of the Healthcare Cost and Utilization Project (HCUP), was queried from 2016 to 2019 to identify all who underwent TMVr. International classification of diseases, tenth revision clinical modification (ICD-10-CM) codes were used to divide patients into frail and non-frail study groups. Frailty was defined using Johns Hopkins Adjusted Clinical Groups diagnosis cluster for frailty. Multivariate linear and logistic regression analysis was performed to compare in-hospital mortality, hospital length of stay, non-home discharge, and iatrogenic cardiac complications among Frail and Non-Frail groups.

Results

A total of 30,660 patients who underwent TMVr were identified. The mean age was 76±11.6 years. Of those, 2,950 (9.6%) were identified as frail. The overall in-hospital mortality rate for the entire study population was 1.89%. Compared to non-frail patients, those identified as frail had greater odds of in-hospital mortality (AOR= 2.13, 95% CI 1.29–3.51, p<0.001) and non-home discharge (AOR= 4.34, 95% CI 3.54–5.32, p<0.001). However, there was no statistically significant difference in hospital length of stay and rates of iatrogenic cardiac complications.

Conclusions

Frailty models continue to be underutilized as a prognostic tool in clinical practice. After following HCUP guidelines, our analysis found that frailty is independently associated with increased in-hospital mortality and non-home discharge in patients undergoing TMVr. Therefore, we recommend that further efforts in incorporating frailty models in the pre-procedural assessment of patients undergoing TMVr should be sought along with a standardized predictive model for defining frailty.

Funding Acknowledgement

Type of funding sources: None.

Impact of left bundle branch block in patients with takotsubo cardiomyopathy

Background

Takotsubo cardiomyopathy (TCM) is a syndrome characterized by reversible left-ventricular regional systolic dysfunction in the absence of obstructive coronary artery disease (CAD). The presence of left bundle branch block (LBBB) has been described as an independent predictor of mortality in patients with CAD. One study using the National Inpatient Sample (NIS) for 2016 found that the presence of LBBB was associated with worse outcomes in patients with TCM.

Purpose

To better clarify the association between LBBB and various in-hospital outcomes in patients with TCM.

Methods

The NIS database was queried from 2016–2019 to identify all admissions with a primary diagnosis of TCM that had a cardiac catheterization to improve the specificity of the diagnosis. International classification of diseases, tenth revision clinical modification (ICD-10-CM) codes were used to divide patients based on the presence or absence of LBBB. A 1:3 propensity score matching based on age, race, gender, and risk factor stratification was used to reduce selection bias. Multivariate linear and logistic regression analysis was performed to compare various outcomes among both groups.

Results

A total of 27,125 patients admitted with a primary diagnosis of TCM that also underwent diagnostic coronary angiography were identified. In the study sample, 955 (3.5%) were determined to have a LBBB. After calculating propensity scores, 955 patients with LBBB were paired to 2,865 patients without LBBB. LBBB was associated with higher rates of ventricular arrhythmias (AOR=3.098, 95% CI 1.483–6.471, p=0.003); however, it was not statistically associated with cardiogenic shock, sudden cardiac arrest (SCA), acute kidney injury, acute heart failure, and hospital length of stay. In addition, there was no statistical difference in intra-hospital mortality.

Conclusions

LBBB is associated with left ventricular dyssynchrony. It has been proposed that intraventricular dyssynchrony might be a predisposing factor for ventricular arrhythmias (VA) and SCA. Several trials have demonstrated that cardiac resynchronization therapy alone (i.e., without defibrillation) reduces the rate of VA and SCA. The mechanism for this improvement is unclear but may be related to hemodynamic improvement from ventricular synchrony in heart failure (HF). In fact, LBBB has been reported as an independent risk factor for all-cause mortality and SCA at one year in patients with HF. Our analysis did not find any significant association between LBBB and SCA but did find an association with VA. Moreover, there were not enough events of intra-hospital mortality to assess a possible association between LBBB and mortality. Therefore, a prospective study with a longer follow-up would be needed to clarify the role of LBBB in mortality and establish causality between LBBB and VA in patients with TCM.

Funding Acknowledgement

Type of funding sources: None.

High rate of autonomic neuropathy in Cornelia de Lange Syndrome

Background

Cornelia de Lange Syndrome (CdLS) is a rare congenital disorder characterized by typical facial features, growth failure, limb abnormalities, and gastroesophageal dysfunction that may be caused by mutations in several genes that disrupt gene regulation early in development. Symptoms in individuals with CdLS suggest that the peripheral nervous system (PNS) is involved, yet there is little direct evidence.

Method

Somatic nervous system was evaluated by conventional motor and sensory nerve conduction studies and autonomic nervous system by heart rate variability, sympathetic skin response and sudomotor testing. CdLS Clinical Score and genetic studies were also obtained.

Results

Sympathetic skin response and sudomotor test were pathological in 35% and 34% of the individuals with CdLS, respectively. Nevertheless, normal values in large fiber nerve function studies.

Conclusions

Autonomic nervous system (ANS) dysfunction is found in many individuals with Cornelia de Lange Syndrome, and could be related to premature aging.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02082-y.

MAU2 and NIPBL Variants Impair the Heterodimerization of the Cohesin Loader Subunits and Cause Cornelia de Lange Syndrome

The NIPBL/MAU2 heterodimer loads cohesin onto chromatin. Mutations in NIPBL account for most cases of the rare developmental disorder Cornelia de Lange syndrome (CdLS). Here we report a MAU2 variant causing CdLS, a deletion of seven amino acids that impairs the interaction between MAU2 and the NIPBL N terminus. Investigating this interaction, we discovered that MAU2 and the NIPBL N terminus are largely dispensable for normal cohesin and NIPBL function in cells with a NIPBL early truncating mutation. Despite a predicted fatal outcome of an out-of-frame single nucleotide duplication in NIPBL, engineered in two different cell lines, alternative translation initiation yields a form of NIPBL missing N-terminal residues. This form cannot interact with MAU2, but binds DNA and mediates cohesin loading. Altogether, our work reveals that cohesin loading can occur independently of functional NIPBL/MAU2 complexes and highlights a novel mechanism protective against out-of-frame mutations that is potentially relevant for other genetic conditions.

Rare Variants in 48 Genes Account for 42% of Cases of Epilepsy With or Without Neurodevelopmental Delay in 246 Pediatric Patients

In order to characterize the genetic architecture of epilepsy in a pediatric population from the Iberian Peninsula (including the Canary Islands), we conducted targeted exome sequencing of 246 patients with infantile-onset seizures with or without neurodevelopmental delay. We detected 107 variants in 48 different genes, which were implicated in neuronal excitability, neurodevelopment, synaptic transmission, and metabolic pathways. In 104 cases (42%) we detected variant(s) that we classified as pathogenic or likely pathogenic. Of the 48 mutated genes, 32 were dominant, 8 recessive and 8 X-linked. Of the patients for whom family studies could be performed and in whom pathogenic variants were identified in dominant or X-linked genes, 82% carried de novo mutations. The involvement of small copy number variations (CNVs) is 9%. The use of progressively updated custom panels with high mean vertical coverage enabled establishment of a definitive diagnosis in a large proportion of cases (42%) and detection of CNVs (even duplications) with high fidelity. In 10.5% of patients we detected associations that are pending confirmation via functional and/or familial studies. Our findings had important consequences for the clinical management of the probands, since a large proportion of the cohort had been clinically misdiagnosed, and their families were subsequently able to avail of genetic counseling. In some cases, a more appropriate treatment was selected for the patient in question, or an inappropriate treatment discontinued. Our findings suggest the existence of modifier genes that may explain the incomplete penetrance of some epilepsy-related genes. We discuss possible reasons for non-diagnosis and future research directions. Further studies will be required to uncover the roles of structural variants, epimutations, and oligogenic inheritance in epilepsy, thereby providing a more complete molecular picture of this disease. In summary, given the broad phenotypic spectrum of most epilepsy-related genes, efficient genomic tools like the targeted exome sequencing panel described here are essential for early diagnosis and treatment, and should be implemented as first-tier diagnostic tools for children with epilepsy without a clear etiologic basis.

Phenomenological friction equation for turbulent flow of Bingham fluids

Most discussions in the literature on the friction coefficient of turbulent flows of fluids with complex rheology are empirical. As a rule, theoretical frameworks are not available even for some relatively simple constitutive models. In the present work, a formula is proposed for the evaluation of the friction coefficient of turbulent flows of Bingham fluids. The developments combine a fresh analysis for the description of the microscales of Kolmogorov and the phenomenological turbulence model of Gioia and Chakraborty [G. Gioia and P. Chakraborty, Phys. Rev. Lett. 96, 044502 (2006)PRLTAO0031-900710.1103/PhysRevLett.96.044502]. The resulting Blasius-type friction equation is tested against some experimental data and shows good agreement over a significant range of Hedstrom and Reynolds numbers. Comments on pressure measurements in yielding fluids are made. The limits of the proposed model are also discussed.

Publisher's Note: Phenomenological Blasius-type friction equation for turbulent power-law fluid flows [Phys. Rev. E 92, 063006 (2015)]

This corrects the article DOI: 10.1103/PhysRevE.92.063006.

Impact of anaemia on health-related quality of life and cardiac remodelling in patients with lower risk myelodysplastic syndromes. Results of GlobQoL study

The aim of this study was to analyse the eventual changes in health-related quality of life (HRQoL) and left ventricular function (LVF) over a 1-year follow-up period in a cohort of patients with lower risk myelodysplastic syndromes (MDS) receiving standard supportive treatment, in order to identify potential clues for early clinical intervention, as well as to analyse how they relate to haemoglobin levels and other aspects of the disease. A total of 39 adult anaemic patients with lower risk MDS were included in a prospective, observational, multi-centre study. Changes in performance status, functional capacity and HRQoL were collected by using standardised measures (ECOG scale; SPPB, Short Physical Performance Battery; SF-36, Short-Form 36 questionnaire; QLQ-C30, Quality of Life Core Questionnaire; FACT-An, Functional Assessment of Cancer Therapy-Anaemia scale questionnaires respectively). Need for transfusion (Linear Analogue Scale Assessment), as perceived independently by the patient and the haematologist, was also recorded. No changes in HRQoL (or LVF) were found, except for slight reductions in SF-36 physical function (P = 0.034), SPPB gait speed (P = 0.038) and FACT-An score (P = 0.029), all without apparent immediate clinical relevance for HRQoL, that were unrelated to changes in haemoglobin level. Periodical evaluation of gait speed may assist the clinician in early detection of patient's occult functional decline before it becomes clinically relevant.

Phenomenological Blasius-type friction equation for turbulent power-law fluid flows

We propose a friction formula for turbulent power-law fluid flows, a class of purely viscous non-Newtonian fluids commonly found in applications. Our model is derived through an extension of the friction factor analysis based on Kolmogorov's phenomenology, recently proposed by Gioia and Chakraborty. Tests against classical empirical data show excellent agreement over a significant range of Reynolds number. Limits of the model are also discussed.

Evolution of maple syrup urine disease in patients diagnosed by newborn screening versus late diagnosis

Maple syrup urine disease (MSUD) is a rare metabolic disorder for which the newborn screening (NBS) is possible but it has not been yet implemented for most Spanish regions. In the present study, we assess the clinical features and outcome of 14 MSUD Spanish patients with similar treatment protocol diagnosed either by NBS or by clinical symptoms. Eight patients were detected by NBS, four classic and four moderate MSUD. The average age at detection was 4.6 days, the mean plasmatic concentration of leucine at diagnosis was 1807 μM; the average number of days with leucine >1000 μM was 0.7 (0-4) and the mean number of total hospitalizations was 1.6 (0-5). Mean follow-up time was 70 months. They had good evolution: all remain asymptomatic, but 2 patients have attention deficit and hyperactivity disorder. Six patients with late diagnosis of classic MSUD were followed during 41 months. All presented with acute encephalopathy during the first month of life, mean leucine levels of 2355 μM, mean number of days with leucine >1000 μM of 6.6 (1-13) and mean number of total hospitalizations of 5.3 (4-7). Only two patients have a psychomotor development index in the lower limit (80 and 83). For all patients a good genotype-phenotype correlation was found and four novel mutations were identified: p.A311H, p.T84S, p.T397L, pL398P. Our study support that NBS improves prognosis of MSUD patients. But early diagnosis and an aggressive treatment together with a close monitoring of leucine levels improve neurological evolution in MSUD patients, even for those not detected by NBS.

Azacitidine frontline therapy for unfit acute myeloid leukemia patients: clinical use and outcome prediction

Hypomethylating agents are able to prolong the overall survival of some patients diagnosed with acute myeloid leukemia. The aim of this study was to evaluate the clinical use of azacitidine as front-line therapy in unfit acute myeloid leukemia (AML) patients and to develop a clinical prediction model to identify which patients may benefit more from the drug. One hundred and ten untreated unfit AML patients received front-line azacitidine therapy in Spain, and response and survival were evaluated in them following European LeukemiaNet (ELN) guidelines. A clinical prediction rule was obtained from this population that was validated and refined in 261 patients treated in France, Austria and Italy. ELN response was achieved in 21.0% of the 371 patients (CI95% 17.0-25.5) and did not depend on bone marrow blast cell percentage. Median overall survival was 9.6 months (CI95% 8.5-10.8) and 40.6% of the patients were alive at 1 year (CI95% 35.5-45.7). European ALMA score (E-ALMA), based on performance status, white blood cell counts at azacitidine onset and cytogenetics, discriminated three risk groups with different survival and response rates. Azacitidine seems a reasonable therapeutic option for most unfit AML patients, i.e. those displaying a favorable or intermediate E-ALMA score.

Diagnosis of ganglionar tuberculosis by endoscopic ultrasonography

INTRODUCTION

The endoscopic ultrasonography (EUS) is an endoscopic technique of proven clinical validity today, having a significant impact on the diagnosis and evaluation of several diseases with a low complication rate. The EUS-fine-needle aspiration (FNA) allows the evaluation of subepithelial lesions, extra-luminal lymph nodes or the gastrointestinal tract that are difficult to access by other methods with safe and high diagnostic accuracy.

AIMS AND METHODS

In the case reported, the EUS-FNA was useful for the differential diagnosis with residual biliary microlithiasis and the diagnosis of non-oncologic pathology.

RESULTS

Male, white, 35-year-old, human immunodeficiency virus and tuberculosis treatment for about 5 months presented with jaundice. No fever, weight loss or abdominal pain. Choluria and hipocholia. History of cholecystectomy for about 1 year due to cholelithiasis. Laboratory tests showed cholestatic jaundice (direct hyperbilirrubinemia). Abdominal ultrasound showed liver without particularities, without biliary dilatation or filling defects. Initially suspected hepatitis due tuberculosis drugs so, the treatment was suspended. After a week with no drugs, no improvement in jaundice was observed. In contrast, a progressive increase indirect bilirubin. EUS performed with identification of mass along the distal common bile duct near the duodenal papilla. FNA performed with the presence of lymphocytes and tuberculosis bacile positive. After, endoscopic retrograde cholangiopancreatography was performed with sphincterotomy and placement of endoprosthesis for biliary drainage. The tuberculosis drugs were restarted with the plan to complete. The jaundice was resoluted. The patient completed 9 months of treatment and abdominal tomography has not identified a mass in that place.

CONCLUSION

The EUS-FNA was proven to be a useful tool for diagnosis of non-oncologic pathologies like tuberculosis.

[Chronic recurrent multifocal osteomyelitis: case series of four patients treated with biphosphonates]

AIM

To report and describe a series of four cases of chronic recurrent multifocal osteomyelitis (CRMO) and to discuss therapeutic options, particularly bisphosphonate therapy.

METHODS

Retrospective review of four CRMO cases in two Pediatric Units in Lisbon, between 2005 and 2010.

RESULTS

Median age of first CRMO symptoms was 11.3 years (range 9-13). The more affected sites were the metaphysis of the long bones, pelvis and coxofemoral joints. Median number of initial bony lesions for each patient was 2.3 (range 1-3) at onset and 3.8 (range 2-6) during the disease course. All patients failed to respond to NSAIDs therapy. Two patients received corticosteroids, with clinical disease remission in only one of them. All patients received bisphosphonates (alendronate in two and pamidronate in two), all with good clinical response and induction of clinical remission in two of them. After a median follow-up period of 4.3 years (range 4-5), three patients are clinically asymptomatic and one patient remains with chronic residual pain.

CONCLUSIONS

The treatment of CRMO is not standardized. Bisphosphonate therapy can be of benefit to patients with relapsing symptoms. Randomized controlled multicentric trials are needed to provide better evidence for universal recommendation and definition of bisphosphonate therapy protocol.