Bimekizumab for the treatment of moderate-to-severe plaque psoriasis: efficacy, safety, pharmacokinetics, pharmacodynamics and transcriptomics from a phase IIa, randomized, double-blind multicentre study

BACKGROUND

Bimekizumab is a monoclonal antibody that selectively inhibits both interleukin (IL)-17A and IL-17F, which is currently under investigation for treatment of moderate-to-severe plaque psoriasis. Maintenance dosing every 4 weeks is well established with IL-17 inhibitors for psoriasis.

OBJECTIVES

To investigate the possible dosing interval during bimekizumab maintenance therapy to maintain clear skin, to inform phase III studies.

METHODS

Forty-nine patients with moderate-to-severe plaque psoriasis received bimekizumab 320 mg at weeks 0/4, followed at week 16 by bimekizumab 320 mg (n = 17) or placebo (n = 32). Efficacy, safety, pharmacokinetics, immunogenicity and biopsy transcriptomic analyses were assessed to week 28.

RESULTS

At week 8, 47% of patients achieved a 100% improvement from baseline in Psoriasis Area and Severity Index (PASI 100), increasing to 57% at week 12 (8 weeks after the second dose) before decreasing. In those who received bimekizumab at week 16, PASI 100 rate increased to comparable peak levels at week 20, but reduced by week 28 to 41% (12 weeks after the third dose). The week 8 transcriptional signature observed in lesional psoriatic skin rapidly normalized to levels consistent with nonlesional skin, resulting in molecular remission. Keratinocyte-related gene products such as CXCL1 (C-X-C motif chemokine ligand 1), IL-8 (encoded by the CXCL8 gene), CCL20 (C-C motif chemokine 20), IL-36γ and IL-17C were profoundly normalized to levels associated with nonlesional skin.

CONCLUSIONS

Here, inhibition of IL-17F in addition to IL-17A resulted in rapid, deep clinical responses. Additionally, profound normalization of keratinocyte biology and the psoriatic transcriptome was observed, including normalization of both IL17 and IL23 gene expression by week 8. These data provide evidence to support evaluation of bimekizumab maintenance dosing both every 8 and every 4 weeks in phase III clinical trials.

Efficacy and Safety of Bimekizumab in Moderate to Severe Hidradenitis Suppurativa: A Phase 2, Double-blind, Placebo-Controlled Randomized Clinical Trial

Question

What is the efficacy and safety of bimekizumab in individuals with moderate to severe hidradenitis suppurativa (HS)?

Findings

In this double-blind, placebo-controlled, phase 2 randomized clinical trial including 90 randomized patients with HS (73 completed the trial), bimekizumab demonstrated clinically meaningful and consistent improvements in participants with HS vs placebo across all assessed outcome measures. Serious adverse events occurred in 2 of 46 bimekizumab-treated participants (4%) and 2 of 21 placebo-treated participants (10%).

Meaning

These initial clinical efficacy and safety data suggest that dual inhibition of interleukin 17A and 17F by bimekizumab may be a viable treatment approach for HS, with the potential to achieve deep responses in clinical outcome measures, and support further evaluation.

Importance

Hidradenitis suppurativa (HS) is a chronic inflammatory disease with a high burden for patients and limited existing therapeutic options.

Objective

To evaluate the efficacy and safety of bimekizumab, a monoclonal IgG1 antibody that selectively inhibits interleukin 17A and 17F in individuals with moderate to severe HS.

Design, Setting, and Participants

This phase 2, double-blind, placebo-controlled randomized clinical trial with an active reference arm was performed from September 22, 2017, to February 21, 2019. The study included a 2- to 4-week screening period, a 12-week treatment period, and a 20-week safety follow-up. Of 167 participants screened at multiple centers, 90 were enrolled. Eligible participants were 18 to 70 years of age with a diagnosis of moderate to severe HS 12 months or more before baseline.

Interventions

Participants with HS were randomized 2:1:1 to receive bimekizumab (640 mg at week 0, 320 mg every 2 weeks), placebo, or reference arm adalimumab (160 mg at week 0, 80 mg at week 2, and 40 mg every week for weeks 4-10).

Main Outcomes and Measures

The prespecified primary efficacy variable was the proportion of participants with a 50% or greater reduction from baseline in the total abscess and inflammatory nodule count with no increase in abscess or draining fistula count (Hidradenitis Suppurativa Clinical Response [HiSCR] at week 12. Exploratory variables included proportion achieving a modified HiSCR with 75% reduction of HiSCR criteria (HiSCR₇₅) or a modified HiSCR with 90% reduction of HiSCR criteria (HiSCR₉₀), change in Patient’s Global Assessment of Pain, and Dermatology Life Quality Index total scores.

Results

Eighty-eight participants received at least 1 dose of study medication (61 [69%] female; median age, 36 years; range, 18-69 years). Seventy-three participants completed the study, including safety follow-up. Bimekizumab demonstrated a higher HiSCR rate vs placebo at week 12 (57.3% vs 26.1%; posterior probability of superiority equaled 0.998, calculated using bayesian analysis). Bimekizumab demonstrated greater clinical improvements compared with placebo. Improvements in the International Hidradenitis Suppurativa Severity Score (IHS4) were seen at week 12 with bimekizumab (mean [SD] IHS4, 16.0 [18.0]) compared with placebo (mean [SD] IHS4, 40.2 [32.6]). More bimekizumab-treated participants achieved positive results on stringent outcome measures compared with placebo. At week 12, 46% of bimekizumab-treated participants achieved HiSCR₇₅ and 32% achieved HiSCR₉₀, whereas 10% of placebo-treated participants achieved HiSCR₇₅ and none achieved HiSCR₉₀; in adalimumab-treated participants, 35% achieved HiSCR₇₅ and 15% achieved HiSCR₉₀. One participant withdrew because of adverse events. Serious adverse events occurred in 2 of 46 bimekizumab-treated participants (4%), 2 of 21 placebo-treated participants (10%), and 1 of 21 adalimumab-treated participants (5%).

Conclusions and Relevance

In this phase 2 randomized clinical trial, bimekizumab demonstrated clinically meaningful improvements across all outcome measures, including stringent outcomes. Bimekizumab’s safety profile was consistent with studies of other indications, supporting further evaluation in participants with HS.

Trial Registration

ClinicalTrials.gov Identifier: NCT03248531

Personalized nuclear imaging protocol in cases with nodular goiter and parathyroid adenoma

A 62 years old woman was diagnosed with multinodular toxic goiter and primary hyperparathyroidism/left parathyroid adenoma by hormonal assessment, ultrasound and nuclear thyroid/parathyroid scans. Cervical ultrasound illustrated a multinodular aspect of the thyroid with solid nodules and cystic-component nodules; the larger one represented a multinodular complex with necrosis areas in the left thyroid lobe, ACR TI-RADS score 4 (moderately suspicious). Functional nuclear imaging was performed for accurate differential diagnosis between thyroid vs. parathyroid localization, between cold vs. hot nodules, and eventually, for guiding the choice of a subsequent Fine-Needle Aspiration Biopsy (FNAB). Scans described an early intense ^99mTc-sestaMIBI uptake with no ^99mTc-pertechnetate uptake in the left thyroid lobe larger nodule. Due to the suspicion of malignancy for this nodule, we performed an additional scan (1 hour before the classical 2 hours parathyroid delayed scan). The intense uptake persists in both delayed scans suggesting no malignant phenotype and which was confirmed after surgery by benign histology. In conclusion, using a ^99mTc-sestaMIBI personalized protocol, related to the radiotracer cellular uptake mechanisms: 1 hour scan (supplementary image, corresponding to the maximum uptake pattern of ^99mTc-sestaMIBI for cancer cells) and 2 hours scan (for parathyroid washout evaluation) may avoid unnecessary extensive thyroid surgery.

The Evolution of the Bacterial Community Between Hospitals, Wastewater Treatment Plants and the Aquatic Environment

Wastewater treatment plants are major interface between rural and urban activities and the natural environment with problems relating to the survival and transmission of the fecal bacteria into streams and rivers. The main goal of this paper was to showed the impact of WWTPs on fecal populations bacteria and their dissemination into the aquatic ecosystems. The sampling campaigns were conducted in 2019 where the hospital and WWTPs wastewater from three cities from the south-eastern part of Romania and the surface water of their emissaries were trimestral collected. The quantitative and qualitative analysis of total and fecal coliforms indicated the efficiency of wastewater treatment processes but at the same time, the contribution of contamination with hospital effluents has been demonstrated. Also, the microbiological results showed the selectivity of the destruction of fecal coliform bacteria between wastewater and surface water.

The Romanian Map of Organic Pollution from Domestic Wastewaters � Seasonal Variations of Anionic Surfactants And Organic Load (COD)

Surfactants represent the major class of chemicals used in the composition of detergents where the predominant groups are anionic surfactants. Because of the large utilization of detergents in different activities (agricultural, industrial, domestic) an important amount of surfactants can accumulate in the domestic and industrial wastewaters, that are discarded to wastewater-treatment plants (WWTP). Furthermore, surfactants could affect the process of biological wastewater treatment due the inhibition of activated sludge and subsequently the water bodies quality through discharge of WWTPs` effluents. In addition, the soil quality decreased through various modes of sludge applied. The concentrations of organic matters discharged in the wastewater systems from Romania have raised the attention of environmental authorities regarding the toxic impact of their components such as anionic surfactants on the environment. The present paper proposed to highlight the background of organic pollution from Romania through the monitoring of the organics amount in water by Chemical Oxygen Demand (COD) and by the specific indicator � Anionic Surfactants (AS). Temporal (winter, spring and summer, 2019) and spatial (six areas: West, North-West, North-East, East, South and South-West) monitoring of organic matter was performed. It has been found that the spatial and temporal variation of AS concentrations were well correlated with COD load, leading to the conclusion that surfactants represented an important part of the global organic matter.

Efficiency of Biocides on the Aquatic Systems Through Bacterial Model

Various biocide technologies have been used successfully in water treatment applications for many years, but their constantly increased production and excessive usage has considerable environmental and economic impacts. In addition, the aggressive use of biocides in more and more fields such as agriculture, livestock growth, and fish farming increased the risk to public health. This measures can lead to the selection of pathogens insusceptible to the main available antimicrobials. Antimicrobials resistance is even more significant when cells are embedded in a biofilm especially in water systems. A variety of microorganisms can be found in swimming pool waters which may be introduced in a number of ways. The disinfection of bathing water is generally achieved by chlorine of chlorine-based products, but alternative more eco-friendly methods such as active oxygen are used more frequently. In this paper, compared the biocides efficiency of two compounds based on chlorine or active oxygen. Although it was assumed that the two biocides have the same mechanism of action and efficiency, we showed in this study that biocides efficiency depends on the bacterial membrane structure and the active oxygen had an increased efficacy against microorganisms compared to chlorine.

Removal and Effects of Surfactants in Activated Sludge System

The widespread use of detergents has raised concern with regard to the environmental pollution caused by their active substances, which are biorefractory, toxic or persistent. Even though anionic and non-ionic surfactants often used in commercial detergents composition are reasonably degradable under aerobic conditions and not particularly toxic at low concentrations, high concentration of surfactants influenced the activated sludge activity and are harmful for the aquatic environment. In the literature, data on the biodegradability and/or ecotoxicity of a certain type of surfactant (anionic, nonionic, cationic) are usually presented. Our study aimed to assess the biodegradability of a mixture of two types of surfactants (anionic mixed with non-ionic) and also, effects caused by their presence of elevated concentrations to the activated sludge micro-organisms, within a batch experiment. We performed a biodegradability test (according Zahn-Wellens method) on 2 synthetic solutions with high concentrations of anionic surfactant �methyl dodecylbenzene sulfonate (15-25 mg/L) and non-ionic surfactant -4-nonylphenyl-polyethylene glycol (10 mg/L). The study established different percent of biodegradability (measured by COD decrease and surfactants removal) depending on initial concentrations of anionic and nonionic surfactants in the tested solutions. High surfactants concentrations modulated the activity and morphology of activated sludge, so its degradation efficiency of the organic substrate has decreased. Surfactant solutions resulting from biodegradability experiment have been tested for toxicity to planktonic crustaceans (Daphnia magna).

Efficacy and safety of bimekizumab as add-on therapy for rheumatoid arthritis in patients with inadequate response to certolizumab pegol: a proof-of-concept study

OBJECTIVE

Evaluate the efficacy and safety of dual neutralisation of interleukin (IL)-17A and IL-17F with bimekizumab, a monoclonal IgG1 antibody, in addition to certolizumab pegol (CZP) in patients with rheumatoid arthritis (RA) and inadequate response (IR) to certolizumab pegol.

METHODS

During this phase 2a, double-blind, proof-of-concept (PoC) study (NCT02430909), patients with moderate-to-severe RA received open-label CZP 400 mg at Weeks 0, 2 and 4, and 200 mg at Week 6. Patients with IR at Week 8 (Disease Activity Score 28-joint count C-reactive protein (DAS28(CRP))>3.2) were randomised 2:1 to CZP (200 mg every 2 weeks (Q2W)) plus bimekizumab (240 mg loading dose then 120 mg Q2W) or CZP plus placebo. The primary efficacy and safety variables were change in DAS28(CRP) between Weeks 8 and 20 and incidence of treatment-emergent adverse events (TEAEs).

RESULTS

Of 159 patients enrolled, 79 had IR at Week 8 and were randomised to CZP plus bimekizumab (n=52) or CZP plus placebo (n=27). At Week 20, there was a greater reduction in DAS28(CRP) in the CZP-IR plus bimekizumab group compared with the CZP-IR plus placebo group (99.4% posterior probability). The most frequent TEAEs were infections and infestations (CZP plus bimekizumab, 50.0% (26/52); CZP plus placebo, 22.2% (6/27)).

CONCLUSIONS

PoC was confirmed based on the rapid decrease in disease activity achieved with 12 weeks of CZP plus bimekizumab. No unexpected or new safety signals were identified when neutralising IL-17A and IL-17F in patients with RA concomitantly treated with CZP, but the rate of TEAEs was higher with dual inhibition.

VITAMIN D DEFICIENCY, A NONINVASIVE MARKER OF STEATOHEPATITIS IN PATIENTS WITH OBESITY AND BIOPSY PROVEN NONALCOHOLIC FATTY LIVER DISEASE

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) includes simple steatosis, steatohepatitis (NASH) which can evolve with progressive fibrosis, cirrhosis and hepatocellular carcinoma. As liver biopsy cannot be used as a screening method, noninvasive markers are needed.

OBJECTIVE

The aim of this study was to test if there is a significant association between vitamin D deficit and the severity of NAFLD.

DESIGN

The patients were divided into two groups (vitamin D insufficiency/deficiency) and statistical analyses were performed on the correlation of clinical and biochemical characteristics with histopathological hepatic changes.

SUBJECTS AND METHODS

We prospectively studied 64 obese patients referred for bariatric surgery between 2014 and 2016 to our Surgical Unit. Anthropometric, clinical measurements, general and specific biological balance were noted. NAFLD diagnosis and activity score (NAS) were evaluated on liver biopsies.

RESULTS

Increased serum fibrinogen was correlated with NASH (p=0.005) and higher NAS grade. T2DM was positively correlated with liver fibrosis (p=0.002). 84.37% of the patients had vitamin D deficit and 15.62% were vitamin D insufficient. Lobular inflammation correlated with vitamin D deficit (p=0.040). Fibrosis (p=0.050) and steatohepatitis (p=0.032) were independent predictors of low vitamin D concentration.

CONCLUSIONS

Vitamin D status in conjunction with other parameters - such as T2DM - or serum biomarkers - namely fibrinogen level and PCR level - may point out the aggressive forms of NAFLD and the need for liver biopsy for appropriate management.

Dual IL-17A and IL-17F neutralisation by bimekizumab in psoriatic arthritis: evidence from preclinical experiments and a randomised placebo-controlled clinical trial that IL-17F contributes to human chronic tissue inflammation

OBJECTIVE

Interleukin (IL)-17A has emerged as pivotal in driving tissue pathology in immune-mediated inflammatory diseases. The role of IL-17F, sharing 50% sequence homology and overlapping biological function, remains less clear. We hypothesised that IL-17F, together with IL-17A, contributes to chronic tissue inflammation, and that dual neutralisation may lead to more profound suppression of inflammation than inhibition of IL-17A alone.

METHODS

Preclinical experiments assessed the role of IL-17A and IL-17F in tissue inflammation using disease-relevant human cells. A placebo-controlled proof-of-concept (PoC) clinical trial randomised patients with psoriatic arthritis (PsA) to bimekizumab (n=39) or placebo (n=14). Safety, pharmacokinetics and clinical efficacy of multiple doses (weeks 0, 3, 6 (240 mg/160 mg/160 mg; 80 mg/40 mg/40 mg; 160 mg/80 mg/80 mg and 560 mg/320 mg/320 mg)) of bimekizumab, a humanised monoclonal IgG1 antibody neutralising both IL-17A and IL-17F, were investigated.

RESULTS

IL-17F induced qualitatively similar inflammatory responses to IL-17A in skin and joint cells. Neutralisation of IL-17A and IL-17F with bimekizumab more effectively suppressed in vitro cytokine responses and neutrophil chemotaxis than inhibition of IL-17A or IL-17F alone. The PoC trial met both prespecified efficacy success criteria and showed rapid, profound responses in both joint and skin (pooled top three doses vs placebo at week 8: American College of Rheumatology 20% response criteria 80.0% vs 16.7% (posterior probability >99%); Psoriasis Area and Severity Index 100% response criteria 86.7% vs 0%), sustained to week 20, without unexpected safety signals.

CONCLUSIONS

These data support IL-17F as a key driver of human chronic tissue inflammation and the rationale for dual neutralisation of IL-17A and IL-17F in PsA and related conditions.

TRIAL REGISTRATION NUMBER

NCT02141763; Results.

Head-to-head comparison of certolizumab pegol versus adalimumab in rheumatoid arthritis: 2-year efficacy and safety results from the randomised EXXELERATE study

BACKGROUND

To date, head-to-head trials comparing the efficacy and safety of biological disease-modifying antirheumatic drugs within the same class, including TNF inhibitors, in patients with active rheumatoid arthritis despite methotrexate therapy are lacking. We aimed to compare the efficacy and safety of two different TNF inhibitors and to assess the efficacy and safety of switching to the other TNF inhibitor without a washout period after insufficient primary response to the first TNF inhibitor at week 12.

METHODS

In this 104-week, randomised, single-blind (double-blind until week 12 and investigator blind thereafter), parallel-group, head-to-head superiority study (EXXELERATE), eligible patients from 151 centres worldwide were aged 18 years or older with a diagnosis of rheumatoid arthritis at screening, as defined by the 2010 ACR/EULAR criteria, and had prognostic factors for severe disease progression, including a positive rheumatoid factor, or anti-cyclic citrullinated peptide antibody result, or both. Participants were randomly assigned (1:1) via an interactive voice and web response system with no stratification to receive certolizumab pegol plus methotrexate or adalimumab plus methotrexate. All study staff were kept masked throughout the study and participants were masked until week 12. At week 12, patients were classified as responders (by either achieving low disease activity [LDA] according to Disease Activity Score 28-erythrocyte sedimentation rate [DAS28-ESR] ≤3·2 or DAS28-ESR reduction ≥1·2 from baseline) or as non-responders. Non-responders to the first TNF inhibitor to which they were randomised were switched to the other TNF inhibitor with no washout period. Primary endpoints were the percentage of patients achieving a 20% improvement according to the American College of Rheumatology criteria (ACR20) at week 12 and LDA at week 104 (week 12 non-responders were considered LDA non-responders). This study is registered with ClinicalTrials.gov, number NCT01500278.

FINDINGS

Between Dec 14, 2011, and Nov 11, 2013, 1488 patients were screened of whom 915 were randomly assigned; 457 to certolizumab pegol plus methotrexate and 458 to adalimumab plus methotrexate. No statistically significant difference was observed in ACR20 response at week 12 (314 [69%] of 454 patients and 324 [71%] of 454 patients; odds ratio [OR] 0·90 [95% CI 0·67-1·20]; p=0·467) or DAS28-ESR LDA at week 104 (161 [35%] of 454 patients and 152 [33%] of 454 patients; OR 1·09 [0·82-1·45]; p=0·532) between certolizumab pegol plus methotrexate and adalimumab plus methotrexate, respectively. At week 12, 65 non-responders to certolizumab pegol were switched to adalimumab and 57 non-responders to adalimumab were switched to certolizumab pegol; 33 (58%) of 57 patients switching to certolizumab pegol and 40 (62%) of 65 patients switching to adalimumab responded 12 weeks later by achieving LDA or a DAS28-ESR reduction 1·2 or greater. 389 [75%] of 516 patients who received certolizumab pegol plus methotrexate and 386 [74%] of 523 patients who received adalimumab plus methotrexate reported treatment-emergent adverse events. Three deaths (1%) occurred in each group. No serious infection events were reported in the 70-day period after treatment switch.

INTERPRETATION

These results show that certolizumab pegol plus methotrexate is not superior to adalimumab plus methotrexate. The data also show the clinical benefit and safety of switching to a second TNF inhibitor without a washout period after primary failure to a first TNF inhibitor.

FUNDING

UCB Pharma.

Certolizumab Pegol Efficacy Across Methotrexate Regimens: A Pre-Specified Analysis of Two Phase III Trials

Objective

Anti–tumor necrosis factor (anti‐TNF) agents are frequently used in combination with methotrexate (MTX) to treat rheumatoid arthritis (RA). We investigated the effect of a background MTX dose, in combination with anti‐TNF certolizumab pegol (CZP), on treatment efficacy and safety in RA patients.

Methods

A pre‐specified subgroup analysis comparing 2 MTX dosage categories (<15 mg/week and ≥15 mg/week) was carried out using data pooled from phase III clinical trials, Rheumatoid Arthritis Prevention of Structural Damage 1 (RAPID 1) and RAPID 2, according to treatment group: CZP 200 mg, CZP 400 mg, or placebo, every 2 weeks. Inclusion criteria required MTX dosage ≥10 mg/week. Efficacy end points included week 24 American College of Rheumatology criteria for 20%, 50%, and 70% improvement (ACR20/50/70) responses analyzed by logistic regression, and changes from baseline in the Disease Activity Score in 28 joints using the erythrocyte sedimentation rate (DAS28‐ESR) and the modified Sharp/van der Heijde score (SHS) were analyzed by analysis of covariance. Incidence rates of treatment‐emergent adverse events (TEAEs) were categorized by baseline MTX dose. Post hoc sensitivity analysis investigated 3 MTX dose categories: ≤10 mg/week, >10 and ≤15 mg/week, and >15 mg/week.

Results

A total of 638, 635, and 325 patients received CZP 200 mg, CZP 400 mg, and placebo, respectively. At week 24, treatment responses in both CZP groups were uninfluenced by baseline MTX dose category, and were superior to the placebo group for all investigated end points: ACR20/50/70, DAS28‐ESR, and SHS. TEAE incidence rates were higher in patients receiving MTX ≥15 mg/week for most TEAE types across treatment groups.

Conclusion

CZP efficacy was not affected by background MTX dose category. It can be hypothesized that to minimize TEAEs, background MTX doses could be tailored to individual patient tolerance without affecting CZP efficacy.

99mTc MIBI THYMIC SCINTIGRAPHY IN DIAGNOSIS AND THERAPEUTIC DECISION MAKING: WHAT IS BEHIND THE IMAGE?

CONTEXT

Despite CT being generally used in thymic pathology, in the case of regions with the same tissue density, only functional radioisotopic imaging can hint towards malignity.

OBJECTIVES

To assess the usefulness of 99mTc MIBI scintigraphy for diagnosis and treatment planning in thymoma, in relation with the radiotracer uptake mechanism.

PATIENTS AND METHODS

99mTc MIBI thymic scans for 19 patients diagnosed with thymic disorders were assessed using tumor uptake ratio (UR). Specimens of thymectomies were examined and cytological assessments were correlated with the UR.

RESULTS

The UR of all surgical patients was higher than 1.2, with a 1.5 cutoff between lymphoid hyperplasia and thymoma. The UR values were correlated with the histopathologic diagnosis (Pearson correlation 0.91, significant at p<0.01). The highest UR was 3.24, found in the case of an AB thymoma where the rate lymphocytes/epithelial cells (L/E) was 1.6. In B1 thymoma UR was 1.14 and L/E was 2.46.

CONCLUSION

Phenotype differences between thymoma types correlate with 99mTc MIBI cellular uptake: lower rate L/E corresponds to higher UR, higher malignity potential and invasiveness. A thymic 99mTc MIBI UR higher than 1.5, corresponding to a CT tumoral image, is suggestive for a thymoma, requiring surgical treatment first.

5 nm structures produced by direct laser writing

Here we present a new approach to overcome the optical diffraction limit by using novel materials. In the paper, we report experimental results obtained by high-resolution transmission electron microscopy (HRTEM) and optical absorption spectroscopy, for a fluorescent photosensitive glass-ceramic containing rare-earth ions such as samarium (Sm). Using a home built dynamic tester, with a low power laser, we recorded nanostructures having 5 nm line widths. In the line structure, measurements reveal the presence of silver nanocrystals with few nanometre sizes. HRTEM shows that there is a random orientation of the nanocrystals. A writing mechanism with three steps is proposed.

Mode switching is the major mechanism of ligand regulation of InsP3 receptor calcium release channels

The inositol 1,4,5-trisphosphate (InsP₃) receptor (InsP₃R) plays a critical role in generation of complex Ca²⁺ signals in many cell types. In patch clamp recordings of isolated nuclei from insect Sf9 cells, InsP₃R channels were consistently detected with regulation by cytoplasmic InsP₃ and free Ca²⁺ concentrations ([Ca²⁺]_i) very similar to that observed for vertebrate InsP₃R. Long channel activity durations of the Sf9-InsP₃R have now enabled identification of a novel aspect of InsP₃R gating: modal gating. Using a novel algorithm to analyze channel modal gating kinetics, InsP₃R gating can be separated into three distinct modes: a low activity mode, a fast kinetic mode, and a burst mode with channel open probability (P_o) within each mode of 0.007 ± 0.002, 0.24 ± 0.03, and 0.85 ± 0.02, respectively. Channels reside in each mode for long periods (tens of opening and closing events), and transitions between modes can be discerned with high resolution (within two channel opening and closing events). Remarkably, regulation of channel gating by [Ca²⁺]_i and [InsP₃] does not substantially alter channel P_o within a mode. Instead, [Ca²⁺]_i and [InsP₃] affect overall channel P_o primarily by changing the relative probability of the channel being in each mode, especially the high and low P_o modes. This novel observation therefore reveals modal switching as the major mechanism of physiological regulation of InsP₃R channel activity, with implications for the kinetics of Ca²⁺ release events in cells.

Graded recruitment and inactivation of single InsP3 receptor Ca2+-release channels: implications for quantal [corrected] Ca2+release

Modulation of cytoplasmic free Ca2+ concentration ([Ca2+]i) by receptor-mediated generation of inositol 1,4,5-trisphosphate (InsP3) and activation of its receptor (InsP3R), a Ca2+-release channel in the endoplasmic reticulum, is a ubiquitous signalling mechanism. A fundamental aspect of InsP3-mediated signalling is the graded release of Ca2+ in response to incremental levels of stimuli. Ca2+ release has a transient fast phase, whose rate is proportional to [InsP3], followed by a much slower one even in constant [InsP3]. Many schemes have been proposed to account for quantal Ca2+ release, including the presence of heterogeneous channels and Ca2+ stores with various mechanisms of release termination. Here, we demonstrate that mechanisms intrinsic to the single InsP3R channel can account for quantal Ca2+ release. Patch-clamp electrophysiology of isolated insect Sf9 cell nuclei revealed a consistent and high probability of detecting functional endogenous InsP3R channels, enabling InsP3-induced channel inactivation to be identified as an inevitable consequence of activation, and allowing the average number of activated channels in the membrane patch (N(A)) to be accurately quantified. InsP3-activated channels invariably inactivated, with average duration of channel activity reduced by high [Ca2+]i and suboptimal [InsP3]. Unexpectedly, N(A) was found to be a graded function of both [Ca2+]i and [InsP3]. A qualitative model involving Ca2+-induced InsP3R sequestration and inactivation can account for these observations. These results suggest that apparent heterogeneous ligand sensitivity can be generated in a homogeneous population of InsP3R channels, providing a mechanism for graded Ca2+ release that is intrinsic to the InsP3R Ca2+ release channel itself.

No relationship between insulin antibodies and transient remission in type 1 diabetic patients

It has been speculated that the insulin antibodies may contribute to the prevention of the onset of the transient remission in insulin-treated diabetic patients. To address this hypothesis, we analysed the titre of insulin antibodies (determined by RIA method, using polyethylenglycol separation technique and expressed as percentage of binding of insulin) in two groups of patients: group A: 46 type 1 diabetics, 25 males and 21 females aged 24 +/- 11.2 years, mean +/- SD, who did not manifest during the first period of the disease any clinical sign of remission; group B: 21 type I diabetics, 13 males and 8 females, aged 25.3 +/- 8.0 years, who manifested in the first year either a partial (18 cases) or a total (3 cases) transient remission. Thirty-eight of cases with disease onset before 1984 were treated with conventional insulins (27 of 46 cases in A group and 11 of 21 cases in B group); the remaining cases were treated with monocomponent (MC) insulins. The binding of the insulin was significantly higher in the patients treated with conventional insulins vs those treated with MC insulins, i.e., 18 +/- 7.1% vs 10.2 +/- 5.2% (p < 0.001). However, no difference was found in the binding of insulin in A group (14.5 +/- 1.3%) compared with B group (13.7 +/- 11.1%). Moreover, in 3 cases from B group the onset of the remission was coincident with the increase of insulin antibodies.

Insulin resistance: the link between impaired glucose tolerance, body mass index and plasma lipids

Body mass index defined as weight (Kg)/height (cm2) and plasma lipids (total lipids-TL, triglycerides-TG and cholesterol-CH) were determined in 131 patients (61 males and 70 females aged between 21 and 63 years) with impaired glucose tolerance (IGT) defined according to WHO criteria. Blood glucose (BG) values and plasma insulin (PI) levels (radioimmunological assay) were determined during 2 hours OGTT with samples obtained before and after 1 h and 2 h after the intake of 75 g glucose. The sum of blood glucose and plasma insulin levels (0 + 1h + 2h) were compared in each of the following 5 groups of subjects: A--25 cases with IGT but without obesity (BMI: 23.2 +/- 2.6) and hyperlipidaemia (PL: 627 +/- 112; TG: 102 +/- 109 and CH: 208 +/- 35 mg/dl); B--35 cases with IGT and obesity (BMI: 31.2 +/- 2.6) but without hyperlipidaemia (PL: 807 +/- 109; TG: 136 +/- 31 and CH: 254 +/- 41 mg/dl); C--23 cases with IGT and hyperlipidaemia (PL: 1013 +/- 217; TG: 214 +/- 85 and CH: 311 +/- 52 mg/dl) but without obesity (BMI: 25.4 +/- 1.9); D--48 cases with IGT and both obesity (BMI: 30.9 +/- 2.8) and hyperlipidaemia (PL: 1457 +/- 155; TG: 597 +/- 188 and CH: 483 +/- 184 mg/dl); a control group of 49 cases without IGT, obesity (BMI: 26.2 +/- 1.9) or hyperlipidaemia (PL: 726 +/- 99 mg/dl).(ABSTRACT TRUNCATED AT 250 WORDS)

Type I and type IV collagen promote adherence and spreading of human type II pneumocytes in vitro

Human lung tissue was enzymatically digested with dispase and type II pneumocytes were subsequently separated on a discontinuous metrizamide gradient. In primary adherence assays with freshly isolated cells, mean adherence values of 21.7, 19.6, 13.4, 6.8 and 7.0% were obtained after 48 hours on type I collagen (CI), type IV collagen (CIV), fibronectin (FN), laminin (LM) and tissue culture plastic, respectively. Secondly, readherence and spreading assays were performed with type II pneumocytes, previously cultured on CI, FN, matrix of murine EHS cells, and culture plastic. After a culture period of 48 to 72 hours, the cells were replated and tested on CI, CIV, FN, LM, CI + FN, CI + LM, CIV + FN and CIV + LM substrata in order to find out whether preculture substrata can modulate the adherence response of these cells. Readherence values, 1 hour after replating, were 3.3- to 8.6-fold higher than primary adherence values after 48 hours. The highest readherence values were always obtained on collagen-containing substrata after preculture on fibronectin. Spreading values after replating ranged between 35.4 and 6.6% on collagen-containing substrata, the highest values were again obtained after preculture on FN. Less than 6.9% and 0.5% of the cells spread on pure FN and pure LM, respectively. The data of the present investigation indicate that human type II pneumocytes adhere and spread preferentially on collagenous substrata rather than on other components of the extracellular matrix. This might be important in helping us to understand the functional in vivo activity of these cells, especially as regards re-epithelialization of the injured pulmonary alveolus.

Circulation of influenza virus A(H1N1) in Moldavia (Romania) during 1978-1982

The influenza virus A(H1N1) subtype that reappeared after an absence of 20 years was incriminated as an etiological agent of acute respiratory disease outbreaks in Moldavia (Romania). There were three epidemics in the winter--spring of 1978, 1979, and 1982, that affected mostly school communities and young adults. In 1980-1981 the circulation of A(H1N1) virus was limited. In all the epidemics mentioned the A(H1N1) subtype caused mild influenza cases, with minimal complications and insignificant mortality.

[Methodolgy and interpretation in the study of the complement system in chronic hepatitis]

The determination of the total hemolitic serum complement, as a screening test for investigating the activity of the entire complement system and the measurement of the C3 fraction consumption, has now gained a peculiar importance due to its contribution to the clearing up of some problems regarding the pathogeny an diagnosis of chronic hepatitis. The correlation of these values alterations with the presence of antiglobulinic antigens orientatively suggests the presence of immune complexes taking part in the maintainance of the inflammatory hepatic process.

Single haemolysis for the assay of antibodies to some haemagglutinating arboviruses

The single radial haemolysis reaction has been shown to be suitable for the quantitative assay of specific antibody to West Nile and Sindbis viruses. Only 5 mul of undiluted serum are needed for the test, which can be performed on crude preparations of antigen and without removal of nonspecific inhibitors. It is therefore a very simple procedure. Moreover, it appears to be more specific than the classical haemagglutination-inhibition tests.

[Posterior (retrovascular) mediastinocervical goiters]

Three cases are presented of endo-thoracic goiters with posterior, retro-vascular developement, a very rare variety of the mediastino-cervical goiter. The anatomic pathways are described, along which this variety of goiter can migrate inside the thorax, as well as the radiologic signs which allow to make a diagnosis. In view of making a choice of the access route the importance of the diagnosis is particularly stressed, before surgery is attempted. It is also demonstrated that the best route is the vertical cervicosternotomy of the partial type (the Welti technique), completed by antero-lateral thoracotomy in the III-rd right intercostal space.

[Details concerning a surgical technic in a case of esophagotracheal fistula]

The authors present a surgical technique for the treatment of oeso-tracheal fistula located in the left supra-hylar fossa, by mobilization of the aorta and ligature of the first intercostal arteries, which provide sufficient light for the surgical procedures. The technique described is illustrated by a personal observation demonstrating its value by the simplicity of the post-operative evolution and the complete recovery. Stressing the difficulty encountered in the pre- and intraoperative localization of the fistula, the authors consider that the technique proposed by them is the type of the necessity technique, the only one allowing to perform a direct surgical approach of the fistula at this level.

[Incomplete form of congenital megacolon]

The inapparent form is described, of a congenital megacolon. The surgical treatment consisted in an exeresis of more than 70 cm of volvular sigmoid, as well as of limitrophic areas supposed to be dystonic. Re-establishment of the continuity was achieved according to the technique of B. Duham 1, modified according to D. Vereanu and A. Pesamosca.