Screening for Anti-HMGCR Antibodies in a Large Single Myositis Center Reveals Infrequent Exposure to Statins and Diversiform Presentation of the Disease.

Background: The objective of this study is to assess the frequency of autoantibodies against 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) in a single center myositis cohort and to analyze associations with statin exposure, clinical features, and outcome of disease course. Methods: A total of 312 patients with idiopathic inflammatory myopathies (IIMs) followed at the rheumatology clinic, Karolinska University Hospital, were identified in the Euromyositis registry between 1988 and 2014 and were classified according to the 2017 European Alliance of Associations for Rheumatology/American College of Rheumatology (EULAR/ACR) criteria. Available serum samples were analyzed for anti-HMGCR autoantibodies by ELISA. Positive sera were confirmed by immunoprecipitation. Clinical data were extracted from Euromyositis registry and medical records. Muscle samples were examined by two pathologists blinded to the subjects' autoantibody status. Results: Of 312 patients, 13 (4.3%) were positive for anti-HMGCR. Two of the 13 (15%) anti-HMGCR-positive patients had histories of statin use versus 12 (4.2%) in the anti-HMGCR-negative group. In the anti-HMGCR-positive group, five (38%) had a clinical phenotype compatible with dermatomyositis. Muscle biopsies of patients with HMGCR autoantibodies showed findings consistent with immune-mediated necrotizing myopathy in all cases except for one. Five (38%) patients required treatment with intravenous immunoglobulin compared to seven (2.3%) without this antibody. At the last visit, seven patients had chronic, active disease course, and five of 13 patients were in remission, including three without treatment. Conclusions: Patients with IIM related to anti-HMGCR autoantibodies may present with a wide range of symptoms, more than previously anticipated. When a broad approach to screening for these antibodies is applied, only a minority of patients was found to have previous statin exposure. The results of this study justify the addition of anti-HMGCR autoantibodies to routine diagnostic procedures in patients with myositis.

Impact of Adipose-Derived Mesenchymal Stem Cells (ASCs) of Rheumatic Disease Patients on T Helper Cell Differentiation.

Complex pathogenesis of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is associated with an imbalance of various Th-cell subpopulations. Mesenchymal stem cells (MSCs) have the ability to restore this balance. However, bone marrow-derived MSCs of SLE and SSc patients exhibit many abnormalities, whereas the properties of adipose derived mesenchymal stem cells (ASCS) are much less known. Therefore, we examined the effect of ASCs obtained from SLE (SLE/ASCs) and SSc (SSc/ASCs) patients on Th subset differentiation, using cells from healthy donors (HD/ASCs) as controls. ASCs were co-cultured with activated CD4+ T cells or peripheral blood mononuclear cells. Expression of transcription factors defining Th1, Th2, Th17, and regulatory T cell (Tregs) subsets, i.e., T-bet, GATA3, RORc, and FoxP3, were analysed by quantitative RT-PCR, the concentrations of subset-specific cytokines were measured by ELISA, and Tregs formation by flow cytometry. Compared with HD/ASCs, SLE/ASCs and especially SSc/ASCs triggered Th differentiation which was disturbed at the transcription levels of genes encoding Th1- and Tregs-related transcription factors. However, we failed to find functional consequences of this abnormality, because all tested ASCs similarly switched differentiation from Th1 to Th2 direction with accompanying IFNγ/IL-4 ratio decrease, up-regulated Th17 formation and IL-17 secretion, and up-regulated classical Tregs generation.

COVID-19 pandemic influence on epilepsy course in pediatric patients.

INTRODUCTION: In 2020, Coronavirus Disease 2019 (COVID-19) was declared as a global pandemic. Self-reported stress, anxiety, and insomnia, which are believed to be common triggers for epilepsy, are more likely to occur. We aimed to establish the influence of COVID-19 pandemic itself on changes in the daily life routine related to pandemic on epilepsy course in pediatric patients. The unique form of clinical care which is telemedicine was also taken into consideration. We wanted to evaluate patients' satisfaction with telemedicine and if changing stationary visits into telemedicine influenced epilepsy course in our patients. METHODS: Patients, who attended developmental neurology outpatient clinic in the period March-December 2020 were collected. As patients were minors, legal guardians were asked to fill out the questionnaire. Patients were divided according to the outcome into three groups: those with a worsened, stable, or improved course of epilepsy during the pandemic. Appropriate statistical tests for two-group and multi-group comparisons have been implemented. Post hoc p values were also calculated. RESULTS: Four hundred and two questionnaires were collected. Most of the patients had a stable course of epilepsy during the pandemic; in 13% of participants an improvement has been observed, worsening of the disease was seen in 16% of patients. Age, sex, type of epilepsy, number of seizure incidents before pandemic, and duration of the disease had no statistically significant connection with changes in the course of the disease. Behavioral changes and altered sleep patterns were found to be more common in the worsened group. Fifty-eight percent of patients were satisfied with telemedicine. Poorer satisfaction was connected with less frequent visits, cancellation of scheduled appointments, and lack of help in case of need in an emergency situation. CONCLUSION: Epilepsy course in pediatric patients seems to be stable during COVID-19 pandemic. Sleep disturbances and changes in a child's behavior may be related to increase in seizure frequency. Telemedicine is an effective tool for supervising children with epilepsy. Patients should be informed about possible ways of getting help in urgent cases.

A woman with a 13-year history of anaplastic thyroid cancer.

Not required for Clinical Vignette.

Bioavailability and pharmacokinetic profile of balovaptan, a selective, brain-penetrant vasopressin 1a receptor antagonist, in healthy volunteers.

BACKGROUND: Balovaptan is a potent, selective vasopressin 1a receptor antagonist. The early-phase pharmacokinetics (PK) of balovaptan are reported. RESEARCH DESIGN AND METHODS: Two Phase 1 studies (overall N = 93) assessed single- and multiple-dose balovaptan PK in healthy adults. One (N = 16) assessed absolute oral bioavailability (10 mg or 50 mg) vs a [13C]-balovaptan microdose. The other (N = 77) explored single- (0.5-76 mg) and multiple-dose (14 days; 12-52 mg/day) - randomized 6:2 balovaptan:placebo per dose - PK, dose proportionality, and the effect of food on single-dose (32 mg) Cmax and AUCinf. RESULTS: Absolute balovaptan bioavailability was high (103-116%). Steady-state (Day 14) balovaptan PK was approximately dose proportional with a half-life of 45-47 hours, but single-dose Cmax increased more than dose proportionally and half-life was inversely dose-proportional - a discordance partially attributable to a dose-and-time-dependent volume of distribution. Accumulation (Day 1-Day 14) was inversely dose-proportional (~3.5 [12 mg] to ~1.8 [52 mg]). There was no relevant effect of a high-fat meal on single-dose balovaptan exposure. There were no safety signals: 2/93 subjects discontinued for adverse events. CONCLUSIONS: Balovaptan was well tolerated at single (≤76 mg) and multiple (≤52 mg/day) doses, with a PK profile supportive of once-daily administration without food restrictions. TRIAL REGISTRATION: ClinicalTrials.gov NCT03764449; NCT01418963.

Modulation of T-Cell Activation Markers Expression by the Adipose Tissue-Derived Mesenchymal Stem Cells of Patients with Rheumatic Diseases.

BACKGROUND: Activated T lymphocytes play an important role in the pathogenesis of rheumatic diseases (RD). Mesenchymal stem cells (MSCs) possess immunoregulatory activities but such functions of MSCs from bone marrow of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and ankylosing spondylitis (AS) patients are impaired. Adipose tissue-derived MSCs (ASCs) are an optional pool of therapeutically useful MSCs, but biology of these cells in RD is poorly known. This study aimed at investigating the effect of ASCs from RD patients and healthy donors (HD) on the expression of the key T-cell activation markers. METHODS: ASCs were isolated from subcutaneous abdominal fat from SLE (n = 16), SSc (n = 18), and AS (n = 16) patients, while five human ASCs lines from HD were used as a control. Untreated and cytokine (tumor necrosis factor α + interferon γ)-treated ASCs were co-cultured with allogenic, mitogen (phytohemagglutinin)-stimulated peripheral blood mononuclear cells (PBMCs) or purified anti-CD3/CD28-activated CD4+ T lymphocytes. Contacting and noncontacting ASCs-PBMCs co-cultures were performed. RD/ASCs were analyzed in co-cultures with both allogeneic and autologous PBMCs. Flow cytometry analysis was used to evaluate expression of CD25, HLA-DR, and CD69 molecules on CD4+ and CD8+ cells. RESULTS: In co-cultures with allogeneic, activated CD4+ T cells and PBMCs, HD/ASCs and RD/ASCs downregulated CD25 and HLA-DR, while upregulated CD69 molecules expression on both CD4+ and CD8+ cells with comparable potency. This modulatory effect was similar in contacting and noncontacting co-cultures. RD/ASCs exerted weaker inhibitory effect on CD25 expression on autologous than allogeneic CD4+ and CD8+ T cells. CONCLUSION: RD/ASCs retain normal capability to regulate expression of activation markers on allogeneic T cells. Both HD/ASCs and RD/ASCs exert this effect independently of their activation status, mostly through the indirect pathway and soluble factors. However, autologous CD4+ and CD8+ T cells are partially resistant to RD/ASCs inhibition of CD25 expression, suggesting weaker control of T-cell activation in vivo.

Safety and Efficacy of Different Doses and Regimens of Faricimab vs Ranibizumab in Neovascular Age-Related Macular Degeneration: The AVENUE Phase 2 Randomized Clinical Trial.

Importance: Faricimab, the first bispecific antibody designed for intraocular use, simultaneously and independently binds and neutralizes angiopoietin 2 (Ang-2) and vascular endothelial growth factor A (VEGF-A). Objective: To assess the efficacy and safety of different doses and regimens of faricimab vs ranibizumab in patients with neovascular age-related macular degeneration (nAMD). Design, Setting, and Participants: AVENUE was a 36-week, multiple-dose-regimen, active comparator-controlled, double-masked, phase 2 randomized clinical study performed at 58 sites in the United States. Eligible participants were anti-VEGF treatment naive with choroidal neovascularization secondary to nAMD and best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study (ETDRS) letter score of 73 (Snellen equivalent, 20/40) to 24 (Snellen equivalent, 20/320). Data were collected from August 11, 2015, to January 12, 2017, with the final patient visit completed September 26, 2017. Data were analyzed from August 11, 2015, to October 4, 2019. Interventions: Patients were randomized 3:2:2:2:3 to receive ranibizumab, 0.5 mg every 4 weeks (arm A [n = 68]); faricimab, 1.5 mg every 4 weeks (arm B [n = 47]); faricimab, 6.0 mg every 4 weeks (arm C [n = 42]); faricimab, 6.0 mg every 4 weeks until week 12, then faricimab, 6.0 mg every 8 weeks (arm D [n = 47]); and ranibizumab, 0.5 mg every 4 weeks until week 8, then faricimab, 6.0 mg every 4 weeks (arm E [n = 69]). Main Outcomes and Measures: Mean change in BCVA from baseline to week 36, proportion of participants gaining at least 15 letters, BCVA of 20/40 or better or 20/200 or worse, and ocular coherence tomographic outcomes in anti-VEGF treatment-naive participants (arms A, B, C, D) and from weeks 12 to 36 in those with incomplete response (participants in arms A and E with week 12 BCVA ETDRS letter score of ≤68 [Snellen equivalent, 20/50 or worse]). Results: A total of 263 participants were included in the analysis (172 [65.4%] female; 258 [98.1%] white; mean [SD] age, 78.3 [8.7] years). At week 36, adjusted mean change in BCVA vs ranibizumab was 1.6 (80% CI, -1.6 to 4.7) letters for arm B (P = .52), -1.6 (80% CI, -4.9 to 1.7) letters for arm C (P = .53), and -1.5 (80% CI, -4.6 to 1.6) letters for arm D (P = .53). For arm E, adjusted mean change from week 12 was -1.7 (80% CI, -3.8 to 0.4) letters (P = .30). Conclusions and Relevance: AVENUE did not meet its primary end point of superiority of faricimab over ranibizumab in BCVA at week 36. Although not superior to monthly ranibizumab as given in this trial, overall visual and anatomical gains noted with faricimab support pursuing phase 3 trials for a potential alternative to monthly anti-VEGF therapy. Faricimab showed no new or unexpected safety signals. Trial Registration: ClinicalTrials.gov Identifier: NCT02484690.

The Phenotype and Secretory Activity of Adipose-Derived Mesenchymal Stem Cells (ASCs) of Patients with Rheumatic Diseases.

Mesenchymal stem/stromal cells (MSCs) have immunosuppressive and regenerative properties. Adipose tissue is an alternative source of MSCs, named adipose-derived mesenchymal stem cells (ASCs). Because the biology of ASCs in rheumatic diseases (RD) is poorly understood, we performed a basic characterization of RD/ASCs. The phenotype and expression of adhesion molecules (intracellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1) on commercially available healthy donors (HD), ASC lines (n = 5) and on ASCs isolated from patients with systemic lupus erythematosus (SLE, n = 16), systemic sclerosis (SSc, n = 17) and ankylosing spondylitis (AS, n = 16) were analyzed by flow cytometry. The secretion of immunomodulatory factors by untreated and cytokine-treated ASCs was measured by ELISA. RD/ASCs have reduced basal levels of CD90 and ICAM-1 expression, correlated with interleukin (IL)-6 and transforming growth factor (TGF)-ß1 release, respectively. Compared with HD/ASCs, untreated and tumour necrosis factor (TNF) + interferon (IFN)-γ (TI)-treated RD/ASCs produced similar amounts of prostaglandin E2 (PGE2), IL-6, leukemia inhibiting factor (LIF), and TGF-ß1, more IL-1Ra, soluble human leukocyte antigen G (sHLA-G) and tumor necrosis factor-inducible gene (TSG)-6, but less kynurenines and galectin-3. Basal secretion of galectin-3 was inversely correlated with the patient's erythrocyte sedimentation rate (ESR) value. IFN-α and IL-23 slightly raised galectin-3 release from SLE/ASCs and AS/ASCs, respectively. TGF-ß1 up-regulated PGE2 secretion by SSc/ASCs. In conclusion, RD/ASCs are characterized by low basal levels of CD90 and ICAM-1 expression, upregulated secretion of IL-1Ra, TSG-6 and sHLA-G, but impaired release of kynurenines and galectin-3. These abnormalities may modify biological activities of RD/ASCs.

Simultaneous Inhibition of Angiopoietin-2 and Vascular Endothelial Growth Factor-A with Faricimab in Diabetic Macular Edema: BOULEVARD Phase 2 Randomized Trial.

PURPOSE: The phase 2 BOULEVARD trial compared safety and efficacy of faricimab, a novel bispecific antibody targeting angiopoietin-2 and vascular endothelial growth factor-A (VEGF-A), with ranibizumab in patients with diabetic macular edema (DME). DESIGN: The BOULEVARD trial (ClinicalTrials.gov identifier, NCT02699450) was a prospective, randomized, active comparator-controlled, double-masked, multicenter, phase 2 study conducted at 59 sites in the United States. PARTICIPANTS: The trial enrolled patients 18 years of age or older with center-involving DME, best-corrected visual acuity (BCVA) of 73 to 24 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, and central subfield thickness (CST) of 325 µm or more. METHODS: Anti-VEGF treatment-naïve patients were randomized 1:1:1 to intravitreal 6.0 mg faricimab, 1.5 mg faricimab, or 0.3 mg ranibizumab, and patients previously treated with anti-VEGF were randomized 1:1 to 6.0 mg faricimab or 0.3 mg ranibizumab. Patients were dosed monthly for 20 weeks, followed by an observation period up to week 36 to assess durability. MAIN OUTCOME MEASURES: The prespecified primary outcome measure was mean change in BCVA from baseline at week 24 for faricimab versus ranibizumab in treatment-naïve patients. Key secondary and exploratory outcome measures included CST, Diabetic Retinopathy Severity Scale (DRSS) score, and durability as assessed by time to re-treatment. RESULTS: The trial enrolled 229 patients (168 treatment-naïve and 61 previously treated with anti-VEGF). In treatment-naïve patients, 6.0 mg faricimab, 1.5 mg faricimab, and 0.3 mg ranibizumab resulted in mean improvements of 13.9, 11.7, and 10.3 ETDRS letters from baseline, respectively. The 6.0-mg faricimab dose demonstrated a statistically significant gain of 3.6 letters over ranibizumab (P = 0.03). In both patient populations, faricimab resulted in dose-dependent reductions in CST, improvements in DRSS score, and longer time to re-treatment during the observation period compared with ranibizumab. Faricimab showed no new or unexpected safety signals. CONCLUSIONS: The BOULEVARD trial met its primary end point; faricimab demonstrated statistically superior visual acuity gains versus ranibizumab at week 24 in treatment-naïve patients. Central subfield thickness reduction, DRSS score improvement, and extended durability outcomes support the primary outcome. These findings suggest the benefit of simultaneous inhibition of angiopoietin-2 and VEGF-A with faricimab for patients with DME.

Differential diagnosis of idiopathic inflammatory myopathies in adults - the first step when approaching a patient with muscle weakness.

Despite its misleading adjective, the most commonly used diagnostic criteria of idiopathic inflammatory myopathies (IIM) are applicable only after all other non-autoimmune muscle diseases have been excluded. It makes differential diagnosis the first step when approaching a patient with muscle weakness. This article is designed to list the most common conditions from which to differentiate in rheumatological care. In fact, many patients with the diseases described here have been initially misdiagnosed with IIM. For the purpose of this article, only the most commonly found and important conditions according to the authors are listed with the essence of information; other autoimmune muscle diseases, such as sarcoidosis and eosinophilic myositis, are not portrayed. The attached bibliography may serve as a source, when further exploration of a specific subject is needed.

Advancements in Understanding Immunogenicity of Biotherapeutics in the Intraocular Space.

Therapeutic breakthroughs in a number of retinal degenerative diseases have come about through the development of biotherapeutics administered directly into the eye. As a consequence of their use, we have gained more insight into the immune privileged status of the eye and the various considerations that development, manufacturing, and use of these drugs require. It has been observed that therapeutic proteins injected into the vitreous can elicit an immune response resulting in the production of anti-drug antibodies (ADAs) which can have clinical consequences. This review includes discussion of the anatomy, physiology, and specific area of the eye that are targeted for drug administration. The various immunologic mechanisms involved in the immune responses to intraocularly administered protein are discussed. This review entails discussion on chemistry, manufacturing, and control (CMC) and formulation-related issues that may influence the risk of immunogenicity. Based on the available immunogenicity profile of the marketed intraocular drugs and their reported adverse events, the animal models and the translational gap from animals to human are discussed. Thus, the objective of this review article is to assess the factors that influence immunogenicity in relation to intraocular administration and the steps taken for mitigating immunogenicity risks.

Phase I Trial of Anti-Vascular Endothelial Growth Factor/Anti-angiopoietin 2 Bispecific Antibody RG7716 for Neovascular Age-Related Macular Degeneration.

PURPOSE: RG7716 is a novel bispecific antibody that simultaneously binds vascular endothelial growth factor (VEGF) and another key angiogenic factor, angiopoietin 2. A phase I study of intravitreal RG7716 was conducted to evaluate single-dose and multiple-dose safety in patients with neovascular age-related macular degeneration (AMD). DESIGN: Open-label, single and multiple ascending-dose study. PARTICIPANTS: Twenty-four patients diagnosed with neovascular AMD with best-corrected visual acuity (BCVA) of 20/40 to 20/400 (Snellen equivalent) and refractory subfoveal choroidal neovascularization defined as leakage on fluorescein angiography or fluid on spectral-domain optical coherence tomography despite 3 or more intravitreal anti-VEGF treatments in the preceding 6 months. METHODS: Single intravitreal doses of 0.5 mg, 1.5 mg, 3 mg, and 6 mg RG7716 were administered in stepwise dose-escalation groups, each with 3 patients. In the multiple-dose phase, 6 patients were enrolled and received 3 treatments each of 3 mg and 6 mg RG7716. MAIN OUTCOME MEASURES: Safety and tolerability, changes in baseline BCVA, and central subfield thickness (CST). RESULTS: There were no dose-limiting toxicities in either the single-dose or multiple-dose group. Treatment-emergent ocular adverse events were mild. There was a single withdrawal and 1 serious adverse event, both deemed to be unrelated to the study drug by principal investigators. In the combined single-dose groups and in the 6-mg multiple-dose group, BCVA increased from baseline to 28 days after the last dose administration by a median of 7 letters (range, 0-18 letters; n = 11) and 7.5 letters (range, 3-18 letters; n = 6), respectively. The corresponding median reduction from baseline in CST were 42 µm (range, -101 to 10 µm; n = 11) and -117 µm (range, -252 to -7 µm; n = 6), respectively. After multiple 3-mg RG7716 doses, no changes were observed in either BCVA (median, -0.5 letters; range, -9 to 8 letters; n = 6) or CST (median, -9 µm; range, -188 to -1 µm; n = 6). CONCLUSIONS: RG7716 was well tolerated and exhibited an overall favorable safety profile, with evidence of improvements in BCVA and anatomic parameters. These data support further evaluation of RG7716 in phase II trials.

Translation strategy for the qualification of drug-induced vascular injury biomarkers.

Drug-induced vascular injury (DIVI) is a common preclinical toxicity usually characterized by hemorrhage, vascular endothelial and smooth muscle damage, and inflammation. DIVI findings can cause delays or termination of drug candidates due to low safety margins. The situation is complicated by the absence of sensitive, noninvasive biomarkers for monitoring vascular injury and the uncertain relevance to humans. The Safer And Faster Evidence-based Translation (SAFE-T) consortium is a public-private partnership funded within the European Commission's Innovative Medicines Initiative (IMI) aiming to accelerate drug development by qualifying biomarkers for drug-induced organ injuries, including DIVI. The group is using patients with vascular diseases that have key histomorphologic features (endothelial damage, smooth muscle damage, and inflammation) in common with those observed in DIVI, and has selected candidate biomarkers associated with these features. Studied populations include healthy volunteers, patients with spontaneous vasculitides and other vascular disorders. Initial results from studies with healthy volunteers and patients with vasculitides show that a panel of biomarkers can successfully discriminate the population groups. The SAFE-T group plans to seek endorsement from health authorities (European Medicines Agency and Food and Drug Administration) to qualify the biomarkers for use in regulatory decision-making processes.

The potential clinical relevance of visible particles in parenteral drugs.

Visible particulates (VP) are one subclass of defects seen during the final visual inspection of parenteral products and are currently one of the top ten reasons for recalls 1,2. The risk posed by particles is still unclear with limited experience reported in humans but remains an important consideration during the manufacture and use of parenteral products. From the experimental and clinical knowledge of the distribution of particulate matter in the body, clinical complications would include events occurring around parenteral administration e.g., as a result of mechanical pulmonary artery obstruction and injection site reaction, or sub-acute or chronic events e.g., granuloma. The challenge is to better understand the implication for patients of single vials with VP and align the risk with the probabilistic detection process used by manufacturers for accept/reject decisions of individual units of product.

A comparative analytical assessment of iodides in healthy and pathological human thyroids based on IC-PAD method preceded by microwave digestion.

The aim of the study was to examine correlations between the content of iodides in 66 nodular goiters and 100 healthy human thyroid tissues (50- frozen and 50 formalin-fixed). A fast, accurate and precise ion chromatography method on IonPac AS11 chromatographic column (Dionex, USA) with a pulsed amperometric detection (IC-PAD) followed by alkaline digestion with tetramethylammonium hydroxide (TMAH) in a closed system and with the assistance of microwaves was developed and used for the comparative analysis of two types of human thyroid samples. Statistical analysis revealed over eightfold reduction of iodine concentration in the pathological tissues (the mean value was 77.13±14.02 ppm) in comparison with the control group (622.62±187.11 ppm for frozen samples and 601.49±192.11 ppm for formalin-fixed ones). A good correspondence (for 10 additional determinations) between the certified (3.38±0.02 ppm with variation coefficient (V.C.) of 0.59% for Standard Reference Material (SRM) NIST 1549-non-fat milk powder) and the measured iodine concentrations (3.52±0.29 ppm; V.C.=10%) was achieved. It was pointed out that the way of tissue preservation (either in formalin or by freezing) had no significant effect on the iodine determination result (α=0.1). Significantly lower iodide content was found in nodular goiter thyroid samples. The applied conditions of digestion, reinforced by the action of microwaves, brought about a decidedly shorter (less than 20 min) sample preparation time. Suitability of the developed IC method was supported by validation results.

Use of ion chromatography for the determination of selected metals in blood serum of patients with type 2 diabetes.

Ion chromatography followed by microwave-induced acid digestion was used to evaluate the serum levels of Fe(3+), Cu(2+), Ni(2+), Zn(2+), and Mn(2+) in patients with diagnosed type 2 diabetes and in healthy controls. Recoveries ranged from 98.0% to 102% for Fe(3+), from 89.9% to 100% for Cu(2+), from 87.9% to 102% for Zn(2+), and from 89.6% to 102% for Mn(2+) were determined by examining samples spiked with various amounts of all the studied ions. The time of mineralization longer than 28 min did not affect the assay values. Precision was assessed at four unique concentrations in replicates of six, on four separate occasions. RSD was determined to be 1.16% for Fe(3+), 5.20% for Cu(2+), 2.8% for Zn(2+), and 3.75% for Mn(2+). The accuracy results (values of RSD) were as follows: 5.16% for Fe(3+), 6.35% for Cu(2+), 4.9% for Zn(2+), and 7.23% for Mn(2+). The statistical analysis confirmed that mean concentrations of Fe(3+) and Zn(2+) did not differ significantly from analogous values in the control group. Patients who additionally suffered from hypertension had higher copper concentrations compared with diabetic patients. For diabetics the presence of Mn(2+) was not stated (LOD values amounting to 0.006 microg/mL). Ni(2+) was not detectable for either the studied group or the control group (LOD=0.006 microg/mL).

[Morphologic changes in photoreceptor connecting cilia in experimental phototoxic retinopathy]. / Zmiany morfologiczne rzeski komórek swiatloczulych w doswiadczalnej retinopatii fototoksycznej.

PURPOSE: It has been suggested that structural alterations of the photoreceptor connecting cilium are a primary defects leading to photoreceptor degeneration in some forms of inherited retinal degenerations (5). In a series of 17 eyes with retinitis pigmentosa (RP) and with various genetic forms of RP, examined by electron microscopy, no structural abnormalities were found in the arrangement of the ciliary microtubules. However, a 10% reduction in the ciliary diameter was recorded in RP photoreceptors (12). The question arose: is thinning of the cilium a primary defect associated with RP, or a secondary abnormality related to degenerative processes in photoreceptors irrespective of the cause? The aim of this study was to examine the photoreceptor connecting cilia in the early stages of experimental light induced retinal degeneration in the rat, by conducting a structural and morphometric survey of the relevant electron-micrographs. In addition, the effects of various fixation techniques on the ciliary structure were compared. MATERIAL AND METHOD: Analysis of 124 transmission electron micrographs of 9 controls and 155 transmission electron micrographs of 55 light damaged animals was conducted. For the effects of fixation on morphometry 72 transmission electron micrographs from an additional 4 controls (43 negatives) and 8 light damaged animals (29 negatives) were examined. Light damage was induced by exposure to 1000 lux of white light for 120 minutes. Retinal samples were fixed either in 2.5% glutaraldehyde or by high pressure freezing followed by freeze-substitution. RESULTS: This study showed that one of the early morphological alterations occurring in rat photoreceptors damaged by light is a reduction of ciliary diameter of approximately 10%. It was not associated with any apparent ultrastructural changes in the axoneme. It was also found that the degree of ciliary shrinkage largely depends on the fixation technique used. Cryo-fixation followed by freeze substitution shows more shrinkage than chemical fixation by immersion in glutaraldehyde. CONCLUSIONS: It is suggested, that reduction in photoreceptor cilium diameter is a secondary and non-specific change. It is not a unique phenomenon, observed not only in human photoreceptors, which are undergoing degeneration in RP. It can be induced in otherwise healthy rat retina, in which photoreceptor degeneration was caused by exposure to toxic levels of light.

[Morphological analysis of age-related changes in the human choroid]. / Analiza zmian morfologicznych zwiazanych z wiekiem w naczyniówce czlowieka.

PURPOSE: To investigate morphologic age-related changes in the human choroid and quantify choriocapillaris density and diameter, Bruch's membrane and entire choroid thickness. MATERIAL AND METHODS: 45 human eyes (aged from 17 to 84) were examined. After fixation of the eyeballs, cross-sections were done and the material was processed for light and electron transmission microscopy. Histomorphometric analysis was performed using H + E slides. Four measurements were performed in each slide at the area of 1000 microns located 4.5 mm temporally from the center of optic disc: Bruch's membrane thickness, longer and shorter diameter of the choriocapillaris, and thickness of the choroid. Statistical analysis was performed. RESULTS: In light and electron microscopy age-related changes were observed at the level of the retinal pigment epithelium, Bruch's membrane, choriocapillaris, and vessels of Sattler's and Haller's layer. Histomorphometric relationships between analyzed features were demonstrated at correlation diagrams. CONCLUSIONS: Age-related thickening of Bruch's membrane, decreased density and diameter of choriocapillaris, and also thinning of the entire choroid was observed.