Microfluidic-based skin-on-chip systems for safety assessment of nanomaterials.

The skin is the body's largest organ, continuously exposed to and affected by natural and anthropogenic nanomaterials (materials with external and internal dimensions in the nanoscale range). This broad spectrum of insults gives rise to irreversible health effects (from skin corrosion to cancer). Organ-on-chip systems can recapitulate skin physiology with high fidelity and potentially revolutionize the safety assessment of nanomaterials. Here, we review current advances in skin-on-chip models and their potential to elucidate biological mechanisms. Further, strategies are discussed to recapitulate skin physiology on-chip, improving control over nanomaterials exposure and transport across cells. Finally, we highlight future opportunities and challenges from design and fabrication to acceptance by regulatory bodies and industry.

Brain Abnormalities in Patients with Germline Variants in H3F3: Novel Imaging Findings and Neurologic Symptoms Beyond Somatic Variants and Brain Tumors.

BACKGROUND AND PURPOSE: Pathogenic somatic variants affecting the genes Histone 3 Family 3A and 3B (H3F3) are extensively linked to the process of oncogenesis, in particular related to central nervous system tumors in children. Recently, H3F3 germline missense variants were described as the cause of a novel pediatric neurodevelopmental disorder. We aimed to investigate patterns of brain MR imaging of individuals carrying H3F3 germline variants. MATERIALS AND METHODS: In this retrospective study, we included individuals with proved H3F3 causative genetic variants and available brain MR imaging scans. Clinical and demographic data were retrieved from available medical records. Molecular genetic testing results were classified using the American College of Medical Genetics criteria for variant curation. Brain MR imaging abnormalities were analyzed according to their location, signal intensity, and associated clinical symptoms. Numeric variables were described according to their distribution, with median and interquartile range. RESULTS: Eighteen individuals (10 males, 56%) with H3F3 germline variants were included. Thirteen of 18 individuals (72%) presented with a small posterior fossa. Six individuals (33%) presented with reduced size and an internal rotational appearance of the heads of the caudate nuclei along with an enlarged and squared appearance of the frontal horns of the lateral ventricles. Five individuals (28%) presented with dysgenesis of the splenium of the corpus callosum. Cortical developmental abnormalities were noted in 8 individuals (44%), with dysgyria and hypoplastic temporal poles being the most frequent presentation. CONCLUSIONS: Imaging phenotypes in germline H3F3-affected individuals are related to brain features, including a small posterior fossa as well as dysgenesis of the corpus callosum, cortical developmental abnormalities, and deformity of lateral ventricles.

Natural history and clinical characteristics of inhibitors in previously treated haemophilia A patients: a case series.

BACKGROUND: Development of inhibitors is the most serious complication in haemophilia A treatment. The assessment of risk for inhibitor formation in new or modified factor concentrates is traditionally performed in previously treated patients (PTPs). However, evidence on risk factors for and natural history of inhibitors has been generated mostly in previously untreated patients (PUPs). The purpose of this study was to examine cases of de novo inhibitors in PTPs reported in the scientific literature and to the EUropean HAemophilia Safety Surveillance (EUHASS) programme, and explore determinants and course of inhibitor development. METHODS: We used a case series study design and developed a case report form to collect patient level data; including detection, inhibitor course, treatment, factor VIII products used and events that may trigger inhibitor development (surgery, vaccination, immune disorders, malignancy, product switch). RESULTS: We identified 19 publications that reported 38 inhibitor cases and 45 cases from 31 EUHASS centres. Individual patient data were collected for 55/83 (66%) inhibitor cases out of 12 330 patients. The median (range) peak inhibitor titre was 4.4 (0.5-135.0), the proportion of transient inhibitors was 33% and only two cases of 12 undergoing immune tolerance induction failed this treatment. In the two months before inhibitor development, surgery was reported in nine (22%) cases, and high intensity treatment periods reported in seven (17%) cases. CONCLUSIONS: By studying the largest cohort of inhibitor development in PTPs assembled to date, we showed that inhibitor development in PTPs, is on average, a milder event than in PUPs.

The triad psoriasis-obesity-adipokine profile.

Psoriasis is a chronic inflammatory skin disease, often associated with overweight/obesity. The adipose tissue is a complex organ that secretes several adipokines, involved in the regulation of some metabolic processes, such as lipid metabolism, glucose homeostasis, angiogenesis, blood pressure and inflammation. In obesity, the distribution and function of adipose tissue, and the adipokine profile are altered. The unbalanced production of pro- and anti-inflammatory adipokines in obesity, contributes to the development of a chronic low-grade inflammation state, which seems to favour worsening of psoriasis lesion and a poorer response to treatment. In this review, we will debate published data concerning the current knowledge about the triad psoriasis-obesity-adipokine profile.

Circulating cell-free DNA levels in Portuguese patients with psoriasis vulgaris according to severity and therapy.

BACKGROUND: Inflammation has a key role in the pathogenesis of psoriasis. Circulating cell-free DNA (CFD) is a marker of tissue cell damage closely associated with inflammation. OBJECTIVES: We aimed to understand the relation of CFD levels with psoriasis severity, defined by the Psoriasis Area and Severity Index (PASI), with inflammation and with psoriasis therapy. METHODS: Forty-six patients with psoriasis vulgaris were evaluated before (T0) and after 12 weeks (T12) of treatment with narrowband ultraviolet light B (NB-UVB; n = 17), psoralen plus UVA (PUVA; n = 20) or topical therapy (n = 9). We evaluated interleukin (IL)-6 and circulating CFD levels. RESULTS: Compared with controls, at T0, patients presented significantly higher levels of circulating CFD. CFD presented a significant positive correlation with IL-6 and a trend towards a positive correlation with PASI. Multiple linear regression analysis identified IL-6 as an independent variable associated with CFD circulating levels. As shown by the PASI score, a trend towards higher values of CFD was observed in the severe psoriasis forms; moderate and severe psoriasis presented also significantly higher CFD values, compared with control. Both NB-UVB and PUVA treatments significantly decreased the levels of CFD. CONCLUSIONS: Patients with psoriasis, at the active stage of the disease, presented an increased inflammation associated with raised circulating CFD levels, which seem to be linked to psoriasis severity. Both NB-UVB and PUVA, anti-inflammatory therapies, were effective in decreasing CFD values. We propose that the evaluation of circulating CFD may provide a new biomarker to monitor psoriasis, its severity and its treatment.

The role of adipocytes in the modulation of iron metabolism in obesity.

A tight relationship between iron deficiency and obesity is known to exist. The chronic low-grade inflammation that characterizes obesity enhances hepcidin production, the principal regulator of iron availability. Adipose tissue is known to secret interleukin-6 and leptin that triggers hepcidin production. It was found that adipose tissue also expresses hepcidin and hemojuvelin, a regulator of hepcidin production. These recent findings suggest that adipose tissue may have an important role in erythropoiesis particularly on obesity that is still poorly clarified. This paper discusses these findings and how they can modulate erythropoiesis.

Calbindin D28K expression in relation to granule cell dispersion, mossy fibre sprouting and memory impairment in hippocampal sclerosis: a surgical and post mortem series.

Reorganisation of the dentate gyrus, including granule cell dispersion (GCD) and mossy fibre sprouting, typically accompany hippocampal sclerosis (HS) in temporal lobe epilepsy. Calbindin (CB) expression in granule cells increases during infancy, influences granule cell excitability, vulnerability to excitotoxicity in addition to important physiological functions in memory. Our aim was to study CB patterns in relation to dentate gyrus re-organisation, epilepsy history and memory function. Forty-five surgical cases and 11 post mortems were examined from patients with drug-resistant epilepsy in addition to three post mortem controls. In the surgical cases, CB expression, and the degree of GCD and mossy fibre sprouting were measured. In post mortem cases, CB expression was assessed in relation to the pattern of HS along the rostral-caudal axis of the hippocampus, and compared to PM controls. Three patterns were identified. In Group 1 (40%), the most dispersed granule cells were CB-positive and basal cells negative imitating developmental patterns. In Group 2 (47%), normal CB expression was retained and in Group 3 (13%), CB was predominantly lost in granule cells. These patterns correlated with GCD, the presence of mossy fibre sprouting and the pattern of HS. Group 1 was associated with early onset of seizures but not independently predictive of outcome. In post mortem cases, altered CB expression lateralised to the side of HS and persisted despite seizure remission in some patients. No significant correlation between CB expression and memory function was identified. CB expression patterns in HS may indicate developmental dysmaturation and are associated with the extent of GCD and mossy fibre sprouting in HS. The functional significance of CB loss, in terms of epileptogenesis and effects on memory, remain uncertain.

Bilateral reorganization of the dentate gyrus in hippocampal sclerosis: a postmortem study.

BACKGROUND: Hippocampal sclerosis (HS) is the most common surgical pathology associated with mesial temporal lobe epilepsy (MTLE). HS is typically characterized by mossy fiber sprouting (MFS) and reorganization of neuropeptide Y (NPY) fiber networks in the dentate gyrus. One potential cause of postoperative seizure recurrence following temporal lobe surgery may be the presence of seizure-associated bilateral hippocampal damage. We aimed to investigate patterns of hippocampal abnormalities in a postmortem series as identified by NPY and dynorphin immunohistochemistry. METHODS: Analysis of dentate gyrus fiber reorganization, using dynorphin (to demonstrate MFS) and NPY immunohistochemistry, was carried out in a postmortem epilepsy series of 25 cases (age range 21-96 years). In 9 patients, previously refractory seizures had become well controlled for up to 34 years prior to death. RESULTS: Bilateral MFS or abnormal NPY patterns were seen in 15 patients including those with bilateral symmetric, asymmetric, and unilateral HS by conventional histologic criteria. MFS and NPY reorganization was present in all classical HS cases, more variably in atypical HS, present in both MTLE and non-MTLE syndromes and with seizure histories of up to 92 years, despite seizure remission in some patients. CONCLUSION: Synaptic reorganization in the dentate gyrus may be a bilateral, persistent process in epilepsy. It is unlikely to be sufficient to generate seizures and more likely to represent a seizure-induced phenomenon.

Insulin-like growth factor I promoter polymorphism, risk of stroke, and survival after stroke: the Rotterdam study.

BACKGROUND AND PURPOSE: Low levels of insulin-like growth factor I (IGF-I) predispose to atherosclerosis and may therefore increase the risk of stroke. Low levels have also been found to influence the outcome of cardiovascular and cerebrovascular disease. A polymorphism in the promoter region of the IGF-I gene influences IGF-I levels. Non-carriers of the 192 bp allele have lower levels of IGF-I compared with 192 bp allele carriers. We studied the IGF-I polymorphism in relation to the risk of stroke and survival after stroke. METHODS: We studied 6808 subjects of the Rotterdam Study, who were followed for the occurrence of stroke and death after stroke. Subjects were grouped according to the 192 bp allele of IGF-I into non-carriers, heterozygotes, and homozygotes. The risk of stroke and survival after stroke was studied using Cox regression analysis, adjusting for age and sex, with homozygotes for the wildtype allele as the reference. RESULTS: Non-carriers had a relative risk of 0.8 (95% CI: 0.6 to 1.0) for the occurrence of any stroke and 0.7 (95% CI: 0.5 to 1.0) for ischaemic stroke. For non-carriers, the relative risk of death after any stroke was 1.5 (95% CI: 1.0 to 2.2). After an ischaemic stroke, this relative risk was 1.5 (95% CI: 0.9 to 2.6) and after a haemorrhagic stroke 5.2 (95% CI: 1.3 to 21.5). CONCLUSIONS: Our study suggests that IGF-I is a significant determinant of survival after stroke.

Erythropoietin levels in the different clinical forms of hereditary spherocytosis.

Erythropoietin (EPO), the main growth factor responsible for the regulation of red blood cell production, may be overproduced when blood loss or haemolysis occurs. Patients with mild hereditary spherocytosis (HS) are able to maintain normal haemoglobin concentration, whereas typical and severe HS patients develop an anaemic state. Splenectomy usually reverses anaemia. We aimed to clarify the role of EPO in the response to enhanced spherocyte destruction, and to look for a linkage with the broad clinical spectra of HS. EPO levels, reticulocyte count and production index (RPI), other parameters used to classify HS and the protein deficiencies underlying HS were evaluated in previously diagnosed unsplenectomised (n = 24) and splenectomised (n = 10) patients presenting mild, typical or severe HS. A significant increase in EPO was observed in all unsplenectomised HS patients. In the mild form, a significant correlation of EPO with reticulocyte count and RPI was observed; however, this correlation disappeared in typical HS patients. Splenectomised HS patients presented a correction in EPO levels in all forms of HS, although the reticulocyte count and RPI sustained slightly higher values. Our data show HS as a disease linked to an overproduction of EPO, according to the severity of the disease; however, a disturbance in erythropoiesis seems to occur in typical HS. Moreover, splenectomy leads to a correction in the EPO levels.

Protein deficiency balance as a predictor of clinical outcome in hereditary spherocytosis.

Vertical and horizontal interactions between membrane constituents account for integrity, strength and deformability of the erythrocyte. Disruption of vertical interactions caused by membrane protein deficiencies in hereditary spherocytosis (HS), favor membrane vesiculation with development of spherocytic cells. Our aim was to evaluate the hematological and clinical presentation of HS according to the type and amount of protein deficiency. We studied 81 Portuguese individuals, 71 belonging to 21 families plus 10 unrelated subjects, and found that 51 of them were HS patients. Patients were classified as presenting mild, typical or severe HS, according to laboratory results and clinical follow-up. We performed screening tests and the standardized electrophoretic membrane protein analysis to identify and quantify protein deficiencies. We found band 3 and ankyrin deficiencies as the major causes for HS. The ratios between the value of the primary and/or secondary protein deficiencies showed significantly different values according to the severity of HS, and a significant inverse correlation with the severity of HS was observed. In mild HS, the ratios between protein deficiencies reflected equivalent protein deficiencies, while an unbalance was observed in typical HS, which was enhanced in severe HS. Our data suggest that the relative quantification of each major membrane protein and of the ratios between the values of protein deficiencies may be helpful in providing additional data about the clinical outcome of HS.

Cardiac rupture during exercise stress echocardiography: a case report.

Stress echocardiography is widely used in the evaluation of coronary artery disease. Dobutamine stress echocardiography has been the preferred method, but many centers have adopted exercise stress echocardiography, which can visualize myocardial motion during physiologic stress testing. The complications of this method in the post-myocardial infarction period are the same as those identified in conventional exercise testing. We report a case of myocardial rupture in the postinfarction period during exercise stress echocardiography.

[Direct coronary angioplasty versus thrombolysis in the acute phase of myocardial infarction--inpatient outcome]. / Angioplastia coronária directa versus trombólise na fase aguda do enfarte do miocárdio--evolução intra-hospitalar.

Both thrombolysis and percutaneous transluminal coronary angioplasty (PTCA) are effective methods for the treatment of acute myocardial infarction (AMI). In our centre we perform primary PTCA during the available schedule of the hemodynamics laboratory. In this article we compare the predischarge evolution of patients submitted to each therapeutic procedure. From January 1996 to June 1997, 298 patients were admitted with the diagnosis of AMI. Eighty-four patients (28%) were thrombolysed (TB group) and 30 patients (10%) underwent primary PTCA (PTCA group). There were no significant differences among the two groups concerning demographic characteristics: age (61 +/- 13--TB and 59 +/- 12 years--PTCA); sex (male 81%--TB; 83%--PTCA), risk factors and previous cardiac history. The mean time since the onset of symptoms until arrival at the hospital was 156 +/- 156 minutes for TB and 202 +/- 210 minutes for PTCA (p < 0.02). The delay since admission until the beginning of treatment was 100 +/- 88 minutes for TB and 119 +/- 142 minutes for PTCA. The primary success rate of PTCA was 94% and there were no complications during the procedure. During the hospital stay, 12 patients developed post-infarction angina in the TB group and two patients in the PTCA group; in 15 patients of the TB group a revascularization procedure was performed (surgery in 5 and PTCA in 10 patients); one patient suffered reinfarction in the TB group. Two patients of the TB group (2.4%) had intracranial hemorrhage; the in-hospital mortality was 9.5% in the TB group and 3.3% in the PTCA (p < 0.001). The mean in-hospital stay was 11 +/- 5.6 in the TB group and 7.8 +/- 2.5 days in the PTCA group (p = 0.055). In our experience, primary PTCA in AMI appeared to be a safe procedure with lower occurrence of coronary events and hemorrhagic complication, with an earlier hospital discharge when compared to thrombolysis.

Idiopathic hypereosinophilic syndrome presenting as cholestatic liver disease.

We report the case of a 34-year-old white man with recurrent episodes of abdominal pain, cholestasis and eosinophilia. The diagnosis of idiopathic hypereosinophilic syndrome (IHS) was made after exclusion of all known causes of eosinophilia. Liver biopsy revealed an eosinophilic infiltrate with biliary damage. The patient recovered after prednisolone treatment. We review the literature on the association between IHS and liver disease.

[Diagnosis of coronary disease using echocardiography with inotropic dobutamine stimulation]. / Diagnóstico de doença coronária através da ecocardiografia com estimulação inotrópica com dobutamina.

PURPOSE: To evaluate dobutamine echocardiography capacity to diagnose coronary artery disease. STUDY DESIGN: Prospective clinical study. SETTING: Cardiology Department of Hospital Santa Marta. PATIENTS: 32 patients with suspected coronary artery disease, without myocardial infarction, have been studied. METHODS: An intravenous perfusion of dobutamine with gradual doses, from 5 to 40 micrograms/kg/min, and increments of 5 to 10 micrograms/kg/min, in 3 minute stages, except the last stage which lasted only 1 minute with 40 micrograms/kg, was performed. Twelve-lead ECG were registered to detect ST changes and symptoms, namely chest pain. Basal and dobutamine bidimensional echocardiograms, in the end of each stage and during recovery, were registered in video. The segmental analysis was performed considering the left ventricle divided in 16 segments. It was considered positive the occurrence or aggravation of the contractility asynergy of the left ventricle with inotropic stress. All the patients were submitted to coronary arteriography. RESULTS: Due to the bad quality of the echocardiographic images 2 patients were excluded. The stress dobutamine echocardiograms were positive in 14 P and negative in 16 P. The coronary arteriography showed coronary disease in 18 cases and absence of significant lesions in 12 cases. The values for sensitivity, specificity positive predictive value and negative predictive value obtained with dobutamine echocardiography were, 78% and 100% and 75% respectively. In Dobutamine-ECG, 7P had ST segment changes, 2 of them with chest pain values for sensitivity, specificity, positive and negative predictive value with dobutamine-ECG were, 39%, 100% and 52%, respectively. The occurrence of side-effects was observed in 8 P (27%): ventricular tachycardia (2 P-7%), complex ventricular ectopy (4 P-13%), chest pain (2 P-7%), headache (1 P-3%), nausea (1 P-3%) and palpitations (2 P-7%). There was no significant difference in the occurrence of side-effects in the two groups of patients, with and without coronary artery disease (33% vs 17%, respectively; p = ns). The reasons for early discontinuation of dobutamine infusion were: ventricular tachycardia (2 P), complex ventricular ectopy (2 P) and chest pain (1 P). Heart rate, systolic blood pressure and double-product did not differ significantly in patients with and without coronary artery disease. In dobutamine electrocardiography 7 P had ST segment changes, 2 of them with chest pain. CONCLUSION: Dobutamine echocardiography showed in this study elevated values for sensitivity and specificity, however sensitivity can be increased with better technical conditions.

[The mechanism producing nausea during ventriculography performed with ioxaglate: the implications of a randomized study]. / Mecanismo de producción de las náuseas durante la ventriculografía realizada con ioxaglato: implicaciones de un estudio randomizado.

INTRODUCTION: The mechanism of ioxaglate-induced nausea has not been fully elucidated. Recent studies have demonstrated that serotonin is one of the principal neurotransmitters of emesis in humans. On the other hand, the greater capacity of ioxaglate to stimulate vomiting has been ascribed to its great ability to inhibit cholinesterase. METHODS: To determine if oral metoclopramide (a serotonin receptor-blocker) is effective in the prophylaxis of ioxaglate-induced nausea during left ventriculography, 637 of 711 consecutive eligible patients were included in a prospective study. Patients were randomized to receive, 60-90 minutes before the procedure, either diazepam 10 mg p.o. (control group [n = 315]) or diazepam 10 mg p.o. plus metoclopramide 10 mg p.o. (metoclopramide group [n = 322]). RESULTS: The two randomized groups were similar in relation to baseline clinical and hemodynamic characteristics. Nausea was documented in 103 patients (16.1%) with similar incidence in the two groups (control group: 16.8%, metoclopramide group: 15.5%; p = NS). Nausea duration was also similar (56 +/- 63 s vs 52 +/- 63 s; p = NS). When patients with and without nausea were compared, the following variables showed a significant difference between the two groups: male gender (86% vs 76%; p < 0.05), age (53 +/- 10 yrs vs 56 +/- 9 yrs; p < 0.05) and body surface area (1.84 +/- 0.2 m2 vs 1.78 +/- 0.1 m2; p < 0.01). Stepwise multiple regression analysis identified low age (p = 0.02) and male gender (p = 0.06) as independent predictors of nausea. The incidence of nausea was 24% in males < or = 45 yrs vs 9% in females > 45 yrs (p < 0.05). CONCLUSIONS: Prophylaxis with oral metoclopramide did not reduce the incidence of ioxaglate-induced nausea during left ventriculography. This data do not support a role of serotonin in the production of nausea by ioxaglate. Low age an male gender are independent predictors of nausea apparition during left ventriculography. A cholinergic mechanism is probably involved in the capacity of ioxaglate to stimulate vomiting.

[Acute myocardial infarct: the prognostic significance of complex coronary lesions]. / Enfarte agudo do miocárdio: significado prognóstico das lesões coronárias complexas.

OBJECTIVE: The aim of our study was to analyze the possible influence of coronary lesion morphology on the prognosis of patients (pts) with Acute Myocardial Infarction (AMI) evaluated by coronary angiography before hospital discharge. DESIGN: Retrospective study. SETTING: Study performed at the Cardiology Department of a Central Hospital. MATERIAL AND METHODS: 141 consecutive pts admitted because of AMI were evaluated, with an age average of 53.4 +/- 9.6 years, who had hospital discharge. All pts were submitted to angiography between the 2nd and 3rd week after AMI. The ventriculography was evaluated to determine the ventricular function score, as defined by the CASS protocol. The coronarography was performed to access the number of diseased vessels and to analyze their lesion morphology. Complexity was defined by the presence of one of the following characteristics: irregularity, shoulder, ulcers, filling defects, contrast retention and ecstasy. TWO GROUPS OF PTS WERE CONSIDERED: Group I--n = 64 pts, with complex lesions, and Group II--n = 69 pts with non complex lesions. Seven pts were excluded from the study because they had no significant coronary disease. Mean time of the follow up was 21.4 +/- 8.5 months and was similar in the two groups. The cardiac events considered were angina after AMI; reinfarction; heart failure; new hospital admission, percutaneous transluminal coronary angioplasty; coronary artery bypass grafting and death. RESULTS: In relation to both groups no statistically significant difference was found concerning sex, age, left ventricular function score and number of diseased vessels. In group I a higher incidence was found for cardiac events (p 0.006) and for the occurrence of angina after AMI (p < 0.02). In this group the number of pts with cardiac events was also higher (p < 0.01). No difference was found in relation to each of the morphologic characteristics and a high risk profile could not be found. CONCLUSIONS: Besides left ventricular function and the number of diseased vessels, the analysis of coronary lesion morphology, evaluated 2 to 3 weeks after AMI, could be useful in risk stratification after AMI.