Early disease intervention with guselkumab in psoriasis leads to a higher rate of stable complete skin clearance ('clinical super response'): Week 28 results from the ongoing phase IIIb randomized, double-blind, parallel-group, GUIDE study

BACKGROUND

Guselkumab is an interleukin (IL)-23 inhibitor with demonstrated efficacy in patients with psoriasis.

OBJECTIVES

Evaluate the impact of early disease intervention on clinical responses following 28 weeks of guselkumab treatment in patients with moderate-to-severe plaque psoriasis. Correlate clinical response and disease duration data with serum biomarker data.

METHODS

GUIDE is a phase IIIb randomized, double-blind, parallel-group, multicentre study of adults with moderate-to-severe plaque psoriasis. In study part 1, patients with a short disease duration (SDD [≤2 years]) or a long disease duration (LDD [>2 years]) received guselkumab 100 mg at Week (W) 0, 4, 12, and 20. Those achieving complete skin clearance at W20 and W28 were defined as a super responder (SRe). A multivariable logistic regression analysed the association between baseline factors and the likelihood of becoming an SRe. The relationship between clinical response, disease duration and serum biomarker data was assessed at W0 and 4.

RESULTS

In total, 880 patients were enrolled (SDD/LDD = 40.6%/59.4% of patients). More SDD than LDD patients achieved absolute Psoriasis Area and Severity Index (PASI) = 0 at W28 (51.8% vs. 39.4%) and were SRes (43.7% vs. 28.1% [overall 34.4%]). SDD patients also achieved PASI = 0 quicker than LDD patients (median 141 vs. 200 days). Disease duration and prior biologic use had the greatest impact on becoming an SRe, with no strong association among these independent variables. At baseline, there were no significant differences in the serum biomarker levels of IL-17A, IL-17F, IL-22 and β-defensin 2 between SDD and LDD patients, or between SRe and non-SRe patients. Guselkumab rapidly decreased these markers of systemic inflammation across all patient groups analysed at W4. Guselkumab was well tolerated.

CONCLUSIONS

Guselkumab efficacy was consistent across subpopulations, on the skin and systemically. The proportion of SRes was higher in SDD than LDD patients, indicating early treatment intervention may improve clinical outcomes.

Effectiveness, safety and quality-of-life effects of guselkumab and ustekinumab in patients with psoriasis: Week 104 results from the non-interventional, prospective, German multicentre PERSIST study

BACKGROUND

PERSIST was a prospective, non-interventional, real-world study of guselkumab and ustekinumab in adult patients with moderate-to-severe plaque psoriasis in Germany.

OBJECTIVES

To examine effectiveness, safety and quality-of-life (QoL) outcomes to Week (W) 104 of treatment with guselkumab and ustekinumab in patients with moderate-to-severe plaque psoriasis.

METHODS

Patients (≥18 years of age) received guselkumab or ustekinumab as per routine clinical practice. Outcomes to W104 were examined separately in guselkumab and ustekinumab recipients. An ad hoc exploratory analysis of outcomes with guselkumab versus ustekinumab was also performed following propensity score matching.

RESULTS

Overall, 302 and 313 patients received guselkumab and ustekinumab, respectively. Patients in both cohorts experienced improvements in disease activity and QoL that were maintained to W104, with 64.7% and 63.6% of guselkumab- and 54.6% and 64.4% of ustekinumab-treated patients achieving a Psoriasis Area and Severity Index (PASI) 90 response and a Dermatology Life Quality Index (DLQI) 0/1 score, respectively. Propensity score matching yielded well-balanced baseline characteristics except for prior biologic use, which was higher in guselkumab versus ustekinumab recipients (51.7% vs. 32.0%). Achievement of PASI ≤1 at W104 was more common in guselkumab versus ustekinumab recipients (58.7% vs. 49.7%). The W104 PASI90 response rate was 65.6% with guselkumab and 56.0% with ustekinumab; corresponding rates for PASI100 were 44.3% and 28.5%. In guselkumab recipients, response rates were higher in biologic-naïve versus biologic-experienced patients (PASI90, 77.1% vs. 53.4%; PASI100, 55.0% vs. 33.0%). A high level of response for QoL outcomes was observed for both treatments.

CONCLUSIONS

Ustekinumab and guselkumab led to improvements in physician-assessed and patient-reported outcomes that were sustained for up to 2 years, with no new safety signals identified. Following propensity score matching, greater improvements in PASI outcomes were observed with guselkumab versus ustekinumab. Improvements with guselkumab were highest in biologic-naïve patients, highlighting the value of early treatment.

Real-world evidence from the non-interventional, prospective, German multicentre PERSIST study of patients with psoriasis after 1 year of treatment with guselkumab

BACKGROUND

PERSIST was a prospective, non-interventional, long-term, German multicentre study of patients with moderate-to-severe psoriasis receiving guselkumab, an approved monoclonal antibody that binds to the p19 subunit of interleukin (IL)-23, in a real-world setting.

OBJECTIVES

Evaluation of the efficacy and safety of guselkumab, and its effect on health-related quality of life (HRQoL), in patients with moderate-to-severe psoriasis who have received 52 weeks of treatment.

METHODS

Patients (≥18 years old) were prescribed guselkumab as per routine clinical practice. End points assessed include Psoriasis Area and Severity Index (PASI), Physician's Global Assessment (PGA), target Nail Psoriasis Severity Index (NAPSI), and the Dermatology Life Quality Index (DLQI).

RESULTS

Overall, 303 patients were enrolled and treated with guselkumab. Mean disease duration was 21.0 years, and 77.2% and 51.2% of patients had received ≥1 prior conventional systemic or ≥1 prior biologic therapy, respectively. Mean PASI score decreased from 16.4 at baseline to 3.0 by Week (W) 28, and further decreased to 2.4 by W52, while the proportion of patients achieving an absolute PASI score of ≤1 increased from 1.3% at baseline, to 50.8% at W28 and to 58.4% by W52. PASI90 and PASI100 responses also showed marked improvements between W28 and W52, regardless of biologic treatment history. Clearance of psoriatic skin was observed in difficult-to-treat areas, with the percentage of patients achieving a PGA score ≤1 increasing between W28 and W52. Guselkumab improved HRQoL; mean DLQI score decreased from 13.7 at baseline to 2.8 by W28, and further decreased to 2.4 by W52. At W52, 64.6% of patients achieved a DLQI score ≤1. The cumulative probability of drug survival was 92.4% at W52.

CONCLUSIONS

Guselkumab is efficacious and well tolerated regardless of previous biologic therapies, comorbidities or psoriasis manifestation in difficult-to-treat areas. No new safety signals were observed.

POS1033 DYNAMICS OF NAIL PSORIASIS WITH GUSELKUMAB TREATMENT AND WITHDRAWAL IN ASSOCIATION WITH SKIN RESPONSE AND PATIENT-REPORTED OUTCOMES: A POST HOC ANALYSIS OF THE VOYAGE 2 PHASE 3 TRIAL

Background

Nail psoriasis can be difficult to treat, affects ~50% of patients with psoriasis and can involve the nail matrix (pitting, leukonychia) and/or nail bed (onycholysis, splinter haemorrhages). Evidence suggests nail psoriasis may be associated with risk of developing psoriatic arthritis, in particular distal interphalangeal joint erosion.1–3 Data to Week (Wk) 24 from VOYAGE 1 and 2, two Phase 3 clinical trials, indicate that the anti-interleukin-23 monoclonal antibody guselkumab (GUS) is more effective than placebo and as effective as adalimumab in treating nail psoriasis.4 Furthermore, GUS is also associated with maintained Psoriasis Area and Severity Index (PASI) following treatment withdrawal in VOYAGE 2; however, nail response is not as well understood in this context.5

Objectives

This VOYAGE 2 post hoc analysis evaluated nail response and its association with skin response and patient-reported outcomes (PROs) in two groups, one experiencing GUS withdrawal and the other receiving continuous GUS.

Methods

Patients had moderate-to-severe plaque psoriasis and nail psoriasis, were initially randomised to GUS, and achieved PASI 90 at Wk 28. Patients were then re-randomised to placebo (GUS withdrawal) or GUS every 8 wks (GUS continuation). Nail Psoriasis Severity Index (NAPSI; grading the most affected nail), fingernail Physician’s Global Assessment (f-PGA), PASI and Dermatology Life Quality Index (DLQI) are reported as observed at Wk 0, 16, 24 and 48.

Results

Among 209 patients, NAPSI, f-PGA, PASI and DLQI showed similar trends in both groups until Wk 24. All endpoints improved from baseline; and at Wk 24, patients in the GUS withdrawal and GUS continuation groups achieved a mean NAPSI of 1.7 and 1.8 (nail matrix 1.0 and 1.0; nail bed 0.7 and 0.8); f-PGA 0.9 and 0.9; PASI 0.6 and 0.6; and DLQI 2.2 and 2.3, respectively (Table 1). Nail changes continued to follow skin trends through Wk 48 (Figure 1); with GUS withdrawal, worsening of PASI and DLQI was proportionally greater than that of NAPSI and f-PGA; with GUS continuation, PASI and DLQI remained fairly stable, and NAPSI and f-PGA continued to improve. Nails were numerically slower to respond to GUS initiation and withdrawal than skin, with a more pronounced delay for nail matrix vs nail bed. In patients who sustained a PASI 90 response at Wk 48, despite GUS withdrawal, a high level of nail response was also maintained.

Table 1.

NAPSI, f-PGA, PASI and DLQI through Wk 48 in GUS withdrawal and GUS continuation groups

Wk 0Wk 16Wk 24Wk 28Wk 48GUS withdrawal*GUSRPlacebon97969696NAPSI5.0 (2.1)2.5 (1.9)1.7 (1.9)1.9 (2.1)Nail matrix2.7 (1.3)1.5 (1.3)1.0 (1.2)0.9 (1.3)Nail bed2.2 (1.2)0.9 (1.0)0.7 (1.0)1.0 (1.1)n98979797f-PGA2.5 (0.8)1.3 (0.9)0.9 (0.8)1.1 (1.0)n101101100100PASI23.1 (9.0)1.3 (2.7)0.6 (1.4)5.2 (6.1)n101101100100DLQI14.5 (6.1)2.8 (4.1)2.2 (3.6)7.0 (7.4)GUS continuationGUSRGUSn108106107105NAPSI4.4 (1.8)2.4 (2.2)1.8 (2.0)1.2 (1.6)Nail matrix2.5 (1.2)†1.4 (1.3)1.0 (1.2)0.7 (1.0)Nail bed1.9 (1.2)1.0 (1.1)0.8 (1.0)0.5 (0.8)n108106107105f-PGA2.4 (0.9)1.1 (0.9)0.9 (0.9)0.7 (0.8)n108108108106PASI22.6 (8.8)1.2 (2.1)0.6 (1.1)1.3 (3.5)n107108108104DLQI14.3 (6.4)2.9 (4.2)2.3 (4.0)1.8 (3.4)

Data are mean (standard deviation). *n=10 reinitiated GUS upon loss of 50% of Wk 28 PASI 90

(at n=1 Wk 36, n=2 Wk 40, n=7 Wk 44); †n=107; R, re-randomisation of PASI 90 responders.

Conclusion

GUS treatment through Wk 48 improved nail psoriasis, skin psoriasis and PROs. When GUS was withdrawn, loss of response was slower in nails vs skin. These findings support that nail outcomes follow skin outcome trends with GUS treatment and that nail outcomes should contribute to evaluation of treatment efficacy and disease progression.2,3,6

References

[1]Robert B. Dermatology 2010; 221 Suppl 1: 1–5;

[2]Antony A et al. J Rheumatol 2019; 46: 1097–102.

[3]Wilson F et al. Arthritis Rheum 2009; 61: 233–39;

[4]Foley P et al. JAMA Dermatol 2018; 154: 676–83;

[5]Conrad C et al. AAD 2021. P26573.

[6]Conrad C et al. Dermatol Ther 2022; 12: 233–41.

Acknowledgements

This analysis was funded by Janssen and medical writing support was provided by OPEN Health Medical Communications.

Disclosure of Interests

William Tillett Speakers bureau: Abbvie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Consultant of: Abbvie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Grant/research support from: Abbvie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer and UCB, Alexander Egeberg Speakers bureau: AbbVie, Almirall, Leo Pharma, Zuellig Pharma Ltd., Galápagos NV, Sun Pharmaceuticals, Samsung Bioepis Co., Ltd., Pfizer, Eli Lilly and Company, Novartis, Union Therapeutics, Galderma, Dermavant, UCB, Mylan, Bristol-Myers Squibb, and Janssen

Pharmaceuticals, Consultant of: AbbVie, Almirall, Leo Pharma, Zuellig Pharma Ltd., Galápagos NV, Sun Pharmaceuticals, Samsung Bioepis Co., Ltd., Pfizer, Eli Lilly and Company, Novartis, Union Therapeutics, Galderma, Dermavant, UCB, Mylan, Bristol-Myers Squibb, and Janssen

Pharmaceuticals, Grant/research support from: Pfizer, Eli Lilly, Novartis, Bristol-Myers Squibb, AbbVie, Janssen Pharmaceuticals, the Danish National Psoriasis Foundation, the Simon Spies Foundation, and the Kgl Hofbundtmager Aage Bang Foundation, Enikö Sonkoly Speakers bureau: AbbVie, Eli Lilly, UCB, Janssen, Novartis, Sanofi and LEO Pharma, Grant/research support from: Pfizer, Patricia Gorecki Employee of: Janssen, Anna Tjärnlund Employee of: Janssen, Jozefien Buyze Employee of: Janssen, Sven Wegner Employee of: Janssen, Dennis McGonagle Speakers bureau: Abbvie, BMS, Celgene, Janssen, Novartis, Lilly, UCB, Grant/research support from: Abbvie, BMS, Celgene, Janssen, Novartis, Lilly, UCB

High throughput transepithelial electrical resistance (TEER) measurements on perfused membrane-free epithelia

Assessment of epithelial barrier function is critically important for studying healthy and diseased biological models. Here we introduce an instrument that measures transepithelial electrical resistance (TEER) of perfused epithelial tubes in the microfluidic OrganoPlate platform. The tubules are grown in microfluidic channels directly against an extracellular matrix, obviating the need for artificial filter membranes. We present TEER measurements on Caco-2 intestinal and renal proximal tubule epithelium. Forty tubules on one single plate were interrogated in less than a minute. We show that TEER measurement is significantly more sensitive than a fluorescent reporter leakage assay in response to staurosporine. We demonstrate a 40-channel time-lapse data acquisition over a 25 hour time period under flow conditions. We furthermore observed a 50% reduction in Caco-2 TEER values following exposure to a cocktail of inflammatory cytokines. To our best knowledge, this is the first instrument of its kind that allows routine TEER studies in perfused organ-on-a-chip systems without interference by artificial filter membranes. We believe the apparatus will contribute to accelerating routine adoption of perfused organ-on-a-chip systems in academic research and in industrial drug development.

Endothelial Cell-Specific Transcriptome Reveals Signature of Chronic Stress Related to Worse Outcome After Mild Transient Brain Ischemia in Mice

Vascular mechanisms underlying the adverse effects that depression and stress-related mental disorders have on stroke outcome are only partially understood. Identifying the transcriptomic signature of chronic stress in endothelium harvested from the ischemic brain is an important step towards elucidating the biological processes involved. Here, we subjected male 129S6/SvEv mice to a 28-day model of chronic stress. The ischemic lesion was quantified after 30 min filamentous middle cerebral artery occlusion (MCAo) and 48 h reperfusion by T2-weighted MRI. RNA sequencing was used to profile transcriptomic changes in cerebrovascular endothelial cells (ECs) from the infarct. Mice subjected to the stress procedure displayed reduced weight gain, increased adrenal gland weight, and increased hypothalamic FKBP5 mRNA and protein expression. Chronic stress conferred increased lesion volume upon MCAo. Stress-exposed mice showed a higher number of differentially expressed genes between ECs isolated from the ipsilateral and contralateral hemisphere than control mice. The genes in question are enriched for roles in biological processes closely linked to endothelial proliferation and neoangiogenesis. MicroRNA-34a was associated with nine of the top 10 biological process Gene Ontology terms selectively enriched in ECs from stressed mice. Moreover, expression of mature miR-34a-5p and miR-34a-3p in ischemic brain tissue was positively related to infarct size and negatively related to sirtuin 1 (Sirt1) mRNA transcription. In conclusion, this study represents the first EC-specific transcriptomic analysis of chronic stress in brain ischemia. The stress signature uncovered relates to worse stroke outcome and is directly relevant to endothelial mechanisms in the pathogenesis of stroke.

Dual PPARα/γ agonist aleglitazar confers stroke protection in a model of mild focal brain ischemia in mice

Abstract

Peroxisome proliferator-activated receptors (PPARs) control the expression of genes involved in glucose homeostasis, lipid metabolism, inflammation, and cell differentiation. Here, we analyzed the effects of aleglitazar, a dual PPARα and PPARγ agonist with balanced affinity for either subtype, on subacute stroke outcome. Healthy young adult mice were subjected to transient 30 min middle cerebral artery occlusion (MCAo)/reperfusion. Daily treatment with aleglitazar was begun on the day of MCAo and continued until sacrifice. Blood glucose measurements and lipid profile did not differ between mice receiving aleglitazar and mice receiving vehicle after MCAo. Aleglitazar reduced the size of the ischemic lesion as assessed using NeuN immunohistochemistry on day 7. Sensorimotor performance on the rotarod was impaired during the first week after MCAo, an effect that was significantly attenuated by treatment with aleglitazar. Smaller lesion volume in mice treated with aleglitazar was accompanied by a decrease in mRNA transcription of IL-1β, Vcam-1, and Icam-1, suggesting that reduced proinflammatory signaling and reduced vascular inflammation in the ischemic hemisphere contribute to the beneficial effects of aleglitazar during the first week after stroke. Further experiments in primary murine microglia confirmed that aleglitazar reduces key aspects of microglia activation including NO production, release of proinflammatory cytokines, migration, and phagocytosis. In aggregate, a brief course of PPARα/γ agonist aleglitazar initiated post-event affords stroke protection and functional recovery in a model of mild brain ischemia. Our data underscores the theme of delayed injury processes such as neuroinflammation as promising therapeutic targets in stroke.

Key messages

PPARα/γ agonist aleglitazar improves stroke outcome after transient brain ischemia.

Aleglitazar attenuates inflammatory responses in post-ischemic brain.

Aleglitazar reduces microglia migration, phagocytosis, and release of cytokines.

Beneficial effects of aleglitazar independent of glucose regulation.

Aleglitazar provides extended window of opportunity for stroke treatment.

Minimizing the t1-noise when using an indirect 1H high-resolution detection of unlabeled samples

The most utilized through-space correlation ¹H-{X} methods with proton indirect detection use two consecutive transfers, ¹H → X and then X → ¹H, with the evolution time t₁ in the middle. When the X isotope is not 100% naturally abundant (NA), only the signal of the protons close to these isotopes is modulated by the ¹H-X dipolar interactions. This signal is theoretically disentangled with phase-cycling from the un-modulated one. However, this separation is never perfect and it may lead to t₁-noise in case of isotopes with very small NA, such as ¹³C or even worse ¹⁵N. One way to reduce this t₁-noise is to minimize, 'purge', during t₁ the un-modulated ¹H magnetization before trying to suppress it with phase-cycling. We analyze experimentally several sequences following the HORROR condition, which allow purging the ¹H transverse magnetization. The comparison is made at three spinning speeds, including very fast ones for ¹H resolution: 27.75, 55.5 and 111 kHz. We show (i) that the efficiency of this purging process increases with the spinning speed, and (ii) that the best recoupling sequences are the two simplest ones: XY and S₁ = SR2¹₂. We then compare the S/N that can be achieved with the two most used ¹H-{X} 2D methods, called D-HMQC and CP-CP. The only difference in between these two methods is that the transfers are done with either two π/2-pulses on X channel (D-HMQC), or two Cross-Polarization (CP) transfers (CP-CP). The first method, D-HMQC, is very robust and should be preferred when indirectly detecting nuclei with high NA. The second method, CP-CP, (i) requires experimental precautions to limit the t₁-noise, and (ii) is difficult to use with quadrupolar nuclei because the two CP transfers are then not efficient nor robust. However, CP-CP is presently the best method to indirectly detect isotopes with small NA, such as ¹³C and ¹⁵N.

Program for the use of antipsychotics with metabolic monitoring in North Carolina medicaid children

Introduction

Children are at greater risk than adults for weight gain and metabolic disorders including hyperlipidemia and diabetes with newer antipsychotics. A web-based safety-monitoring program using a prior documentation model required submission of patient safety data (prior documentation) for insurance coverage at the pharmacy point of sale. This program launched in April of 2011, covering all NC Medicaid and Health Choice recipients under age 18. Clinical monitoring parameters and interactive educational features were developed with pediatric psychiatric experts and key mental health stakeholder groups.

Objectives

Using a four-year run in period and a full 9 months of post implementation claims data, evaluate the rates of antipsychotic prescribing and safety monitoring before and after the implementation of the A + KIDS program.

Results

Implementation of this program was associated with a consistent monthly decrease in overall antipsychotic use and increases in patient monitoring of glucose and lipid (Figure. 1, Table 1).

Conclusions

The prior documentation registry was effective in decreasing antipsychotic use and increasing safety monitoring. The impact of changing to more traditional prior authorization on the same clinical endpoints is currently under evaluation.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Outflow and clogging of shape-anisotropic grains in hoppers with small apertures

Outflow of granular material through a small orifice is a fundamental process in many industrial fields, for example in silo discharge, and in everyday's life. Most experimental studies of the dynamics have been performed so far with monodisperse disks in two-dimensional (2D) hoppers or spherical grains in 3D. We investigate this process for shape-anisotropic grains in 3D hoppers and discuss the role of size and shape parameters on avalanche statistics, clogging states, and mean flow velocities. It is shown that an increasing aspect ratio of the grains leads to lower flow rates and higher clogging probabilities compared to spherical grains. On the other hand, the number of grains forming the clog is larger for elongated grains of comparable volumes, and the long axis of these blocking grains is preferentially aligned towards the center of the orifice. We find a qualitative transition in the hopper discharge behavior for aspect ratios larger than ≈6. At still higher aspect ratios >8-12, the outflowing material leaves long vertical holes in the hopper that penetrate the complete granular bed. This changes the discharge characteristics qualitatively.

Combined use of EPR and 23Na MAS NMR spectroscopy for assessing the properties of the mixed cobalt–nickel–manganese layers of P3-NayCo1−2xNixMnxO2

EPR and ²³Na MAS NMR are used to gain insights into the structural peculiarities of the mixed cobalt–nickel–manganese layers of P3-Na_yCo_1−2xNi_xMn_xO₂.

Repression of telomere-associated genes by microglia activation in neuropsychiatric disease

Microglia senescence may promote neuropsychiatric disease. This prompted us to examine the relationship between microglia activation states and telomere biology. A panel of candidate genes associated with telomere maintenance, mitochondrial biogenesis, and cell-cycle regulation were investigated in M1- and M2-polarized microglia in vitro as well as in MACS-purified CD11b+ microglia/brain macrophages from models of stroke, Alzheimer's disease, and chronic stress. M1 polarization, ischemia, and Alzheimer pathology elicited a strikingly similar transcriptomic profile with, in particular, reduced expression of murine Tert. Our results link classical microglia activation with repression of telomere-associated genes, suggesting a new mechanism underlying microglia dysfunction.

A novel human immunodeficiency virus type 1 reverse transcriptase mutational pattern confers phenotypic lamivudine resistance in the absence of mutation 184V

We describe a new human immunodeficiency virus type 1 (HIV-1) mutational pattern associated with phenotypic resistance to lamivudine (3TC) in the absence of the characteristic replacement of methionine by valine at position 184 (M184V) of reverse transcriptase. Combined genotypic and phenotypic analyses of clinical isolates revealed the presence of moderate levels of phenotypic resistance (between 4- and 50-fold) to 3TC in a subset of isolates that did not harbor the M184V mutation. Mutational cluster analysis and comparison with the phenotypic data revealed a significant correlation between moderate phenotypic 3TC resistance and an increased incidence of replacement of glutamic acid by aspartic acid or alanine and of valine by isoleucine at residues 44 and 118 of reverse transcriptase, respectively. This occurred predominantly in those isolates harboring zidovudine resistance-associated mutations (41L, 215Y). The requirement of the combination of mutations 41L and 215Y with mutations 44D and 44A and/or 118I for phenotypic 3TC resistance was confirmed by site-directed mutagenesis experiments. These data support the assumption that HIV-1 may have access to several different genetic pathways to escape drug pressure or that the increase in the frequency of particular mutations may affect susceptibility to drugs that have never been part of a particular regimen.

Needle-like apatite-leucite glass-ceramic as a base material for the veneering of metal restorations in dentistry

A needle-like apatite-leucite glass-ceramic was prepared in the SiO2-Al2O3-Na2O-K2O-P2O5-F system. Nucleation and crystallization processes were studied in bulk and powdered samples. The crystallization of leucite follows the mechanism of surface crystallization. After the precipitation of NaCaPO4 crystals and another unknown crystal phase, the formation of needle-like apatite is based on a volume nucleation and crystallization process. The mechanism of the formation of needle-like apatite differs to those of apatite precipitation in glass-ceramics. The morphology of needle-like apatite is comparable to that of apatite in natural teeth. The properties of the glass-ceramic, especially the good chemical durability, the optical properties, as well as mechanical and thermal properties allow glass-ceramic to be used as a main component in a bio-material for the veneering of metal restorations in dentistry.

New algorithmic approaches to protein spot detection and pattern matching in two-dimensional electrophoresis gel databases

Protein spot identification in two-dimensional electrophoresis gels can be supported by the comparison of gel images accessible in different World Wide Web two-dimensional electrophoresis (2-DE) gel protein databases. The comparison may be performed either by visual cross-matching between gel images or by automatic recognition of similar protein spot patterns. A prerequisite for the automatic point pattern matching approach is the detection of protein spots yielding the x(s),y(s) coordinates and integrated spot intensities i(s). For this purpose an algorithm is developed based on a combination of hierarchical watershed transformation and feature extraction methods. This approach reduces the strong over-segmentation of spot regions normally produced by watershed transformation. Measures for the ellipticity and curvature are determined as features of spot regions. The resulting spot lists containing x(s),y(s),i(s)-triplets are calculated for a source as well as for a target gel image accessible in 2-DE gel protein databases. After spot detection a matching procedure is applied. Both the matching of a local pattern vs. a full 2-DE gel image and the global matching between full images are discussed. Preset slope and length tolerances of pattern edges serve as matching criteria. The local matching algorithm relies on a data structure derived from the incremental Delaunay triangulation of a point set and a two-step hashing technique. For the incremental construction of triangles the spot intensities are considered in decreasing order. The algorithm needs neither landmarks nor an a priori image alignment. A graphical user interface for spot detection and gel matching is written in the Java programming language for the Internet. The software package called CAROL (http://gelmatching.inf.fu-berlin.de) is realized in a client-server architecture.

Evaluation of segmentation algorithms for generation of patient models in radiofrequency hyperthermia

Time-efficient and easy-to-use segmentation algorithms (contour generation) are a precondition for various applications in radiation oncology, especially for planning purposes in hyperthermia. We have developed the three following algorithms for contour generation and implemented them in an editor of the HyperPlan hyperthermia planning system. Firstly, a manual contour input with numerous correction and editing options. Secondly, a volume growing algorithm with adjustable threshold range and minimal region size. Thirdly, a watershed transformation in two and three dimensions. In addition, the region input function of the Helax commercial radiation therapy planning system was available for comparison. All four approaches were applied under routine conditions to two-dimensional computed tomographic slices of the superior thoracic aperture, mid-chest, upper abdomen, mid-abdomen, pelvis and thigh; they were also applied to a 3D CT sequence of 72 slices using the three-dimensional extension of the algorithms. Time to generate the contours and their quality with respect to a reference model were determined. Manual input for a complete patient model required approximately 5 to 6 h for 72 CT slices (4.5 min/slice). If slight irregularities at object boundaries are accepted, this time can be reduced to 3.5 min/slice using the volume growing algorithm. However, generating a tetrahedron mesh from such a contour sequence for hyperthermia planning (the basis for finite-element algorithms) requires a significant amount of postediting. With the watershed algorithm extended to three dimensions, processing time can be further reduced to 3 min/slice while achieving satisfactory contour quality. Therefore, this method is currently regarded as offering some potential for efficient automated model generation in hyperthermia. In summary, the 3D volume growing algorithm and watershed transformation are both suitable for segmentation of even low-contrast objects. However, they are not always superior to user-friendly manual programs for contour generation. When the volume growing algorithm is used, the contours have to be postprocessed with suitable filters. The watershed transformation has a large potential if appropriately developed to 3D sequences and 3D interaction features. After all, the practicality and feasibility of every segmentation method critically depend on various details of the user software as pointed out in this article.

Transcriptional regulation of the rat vascular endothelial growth factor gene by hypoxia

Vascular endothelial growth factor (VEGF), a potent angiogenic factor and endothelial cell-specific mitogen, is up-regulated by hypoxia. However, the mechanism(s) responsible for hypoxic induction of VEGF has not been clearly delineated. We report that the steady state VEGF mRNA levels are increased 12 +/- 0.6-fold, but the transcriptional rate for VEGF is increased only 3.1 +/- 0.6-fold by hypoxia in PC12 cells. In order to investigate cis-regulatory sequences which mediate this response to hypoxia, we cloned the rat genomic sequences encoding VEGF and identified a 28-base pair element in the 5' promoter that mediates hypoxia-inducible transcription in transient expression assays. This element has sequence and protein binding similarities to the hypoxia-inducible factor 1 binding site within the erythropoietin 3' enhancer. Post-transcriptional mechanisms have also been suggested to play a role in the hypoxic induction of VEGF. Evidence is provided that a frequently used polyadenylation site is 1.9 kilobases downstream from the translation termination codon for rat VEGF. This site is 1.5 kilobases further downstream from the polyadenylation site previously reported for VEGF. This new finding reveals sequence motifs in the 3'-untranslated region that may mediate VEGF mRNA stability.

Relapsing illness due to Rochalimaea henselae in immunocompetent hosts: implication for therapy and new epidemiological associations

Two previously healthy, immunocompetent men had persistent Rochalimaea henselae bacteremia with clinical relapses after courses of antibiotics to which the isolates were ultimately demonstrated susceptible in vitro. Both had sustained tick bites prior to their illnesses, thus demonstrating an association not previously identified, although suspected. The first patient had relapsing fever, constitutional symptoms, and an episode of aseptic meningitis despite therapy with amoxicillin, then with doxycycline, and then with ceftriaxone. Thereafter, he spontaneously became asymptomatic during a span of 2 months of persistent bacteremia. Finally, after 2 weeks of therapy with ceftriaxone plus gentamicin, followed by 4 weeks of therapy with oral ciprofloxacin, his bacteremia was cured. The second man had relapsing fever and constitutional symptoms after courses of tetracycline, then of chloramphenicol, and then of doxycycline. He became permanently asymptomatic after serial 2-week courses of chloramphenicol and erythromycin. The greater efficacy of lysis-centrifugation blood cultures in the recovery of R. henselae was noted.

An indirect method for evaluation of left ventricular function in acute myocardial infarction

An indirect estimate of the contractility index, max LV dP/dt/LVEDP, has been examined in 32 patients following acute myocardial infarction (AMI) and in three patients with acute coronary insufficiency (ACI). The index was derived from arterial diastolic pressure (DP) obtained by sphygmomanometer, left ventricular filling pressure (LVFP) obtained by pulmonary artery balloon catheter, and preejection period (PEP) determined from the phonocardiogram, carotid pulse, and ECG. These data were used in the relation (DP-LVFP)/PEP/LVFP (i.e., ΔP/Δt/LVFP) as an approximation of the direct contractility index max dP/dt/LVEDP. While measurements of PEP, DP, and LVFP used independently were not useful in distinguishing patients grouped in surviving AMI, nonsurviving AMI, and ACI categories, the ΔP/Δt/LVFP index showed marked separation of these groups. Because of the simplicity of measurement and minimal intravascular intervention, the index provides a safe and practical means of assessing the degree of left ventricular dysfunction in patients with AMI.