Creating new guidelines on how best to treat foot symptoms in people with EB

Epidermolysis bullosa (EB) is a complex rare condition that affects the skin and many parts of the body. Those born with EB have skin so fragile they are called 'butterfly children', their skin is quite simply as fragile as the wing of a butterfly. In the UK it is estimated that there are more than 5,000 people living with EB and 500,000 worldwide. Little clinical guidance for care existed until DEBRA International started a programme to develop clinical practice guidelines (CPGs). There were no previous guidelines and few published studies on foot care in EB so treatment decisions were largely based on individual opinion and experience. The panel - made up of clinical experts and people living with EB representing Australia, the UK, and the USA - aimed to describe foot problems in people of all ages with EB, and summarise current evidence and management. The authors used a logical podiatric (foot) care literature review focussed on patients with EB. The authors found that the evidence in this area was limited but several interventions (treatments) currently practised by podiatrists show positive outcomes. The study allowed the group to make recommendations on how to treat foot and nail disorders in patients with EB. Furthermore, the authors concluded that further research is needed. This is a summary of the study: Foot care in epidermolysis bullosa: evidence-based guideline.

Foot care in epidermolysis bullosa: evidence-based guideline

This guideline was designed to provide service providers and users with an evidence-based set of current best practice guidelines for people and their families and carers, living with epidermolysis bullosa (EB). A systematic literature review relating to the podiatric care of patients with EB was undertaken. Search terms were used, for which the most recent articles relating to podiatric treatment were identified from as early as 1979 to the present day, across seven electronic search engines: MEDLINE, Wiley Online Library, Google Scholar, Athens, ResearchGate, Net and PubFacts.com. The Scottish Intercollegiate Guidelines Network (SIGN) methodology was used. The first guideline draft was analysed and discussed by clinical experts, methodologists and patients and their representatives at four panel meetings. The resulting document went through an external review process by a panel of experts, other healthcare professionals, patient representatives and lay reviewers. The final document will be piloted in three different centres in the U.K. and Australia. Following an EB community international survey the outcomes indicated six main areas that the community indicated as a priority to foot management. These include blistering and wound management, exploring the most suitable footwear and hosiery for EB, management of dystrophic nails, hyperkeratosis (callus), maintaining mobility and fusion of toes (pseudosyndactyly). The evidence here is limited but several interventions currently practised by podiatrists show positive outcomes.

Bone mineral density response rates are greater in patients treated with abaloparatide compared with those treated with placebo or teriparatide: Results from the ACTIVE phase 3 trial

BACKGROUND

Abaloparatide is a 34-amino acid peptide that selectively binds to the RG conformation of the parathyroid hormone receptor type 1. It was developed for the treatment of women with postmenopausal osteoporosis at high risk of fracture. In ACTIVE, an 18-month phase 3 study (NCT01343004), abaloparatide increased bone mineral density (BMD), decreased the risk of vertebral and nonvertebral fractures compared with placebo, and decreased the risk of major osteoporotic fractures compared with placebo and teriparatide. Here, we report a prospective, exploratory BMD responder analysis from ACTIVE.

METHODS

Proportions of patients experiencing BMD gains from baseline of >0%, >3%, and >6% at the total hip, femoral neck, and lumbar spine at 6, 12, and 18 months of treatment were compared among the placebo, abaloparatide, and teriparatide groups in ACTIVE. Responders were defined prospectively as patients experiencing BMD gains at all 3 anatomic sites.

RESULTS

At months 6, 12, and 18, there were significantly more >3% BMD responders in the abaloparatide group compared with placebo and teriparatide: month 6, 19.1% vs 0.9% for placebo and 6.5% for teriparatide; month 12, 33.2% vs 1.5% and 19.8%; month 18, 44.5% vs 1.9% and 32.0% (P < 0.001 for all comparisons of abaloparatide to placebo and to teriparatide). Findings were similar for the >0% and >6% responder thresholds.

CONCLUSIONS

In postmenopausal women with osteoporosis, a significantly greater proportion of patients treated with abaloparatide experienced increases in BMD than did those treated with placebo or teriparatide.

Abaloparatide-SC improves trabecular microarchitecture as assessed by trabecular bone score (TBS): a 24-week randomized clinical trial

In a phase 2 trial of 222 postmenopausal women with osteoporosis aged 55 to 85 years randomized to one of three different doses of abaloparatide-SC, subcutaneous teriparatide, or placebo for 24 weeks, abaloparatide-SC resulted in improvements in skeletal microarchitecture as measured by the trabecular bone score.

INTRODUCTION

Subcutaneous abaloparatide (abaloparatide-SC) increases total hip and lumbar spine bone mineral density and reduces vertebral and non-vertebral fractures. In this study, we analyzed the extent to which abaloparatide-SC improves skeletal microarchitecture, assessed indirectly by trabecular bone score (TBS).

METHODS

This is a post hoc analysis of a phase 2 trial of 222 postmenopausal women with osteoporosis aged 55 to 85 years randomized to abaloparatide-SC (20, 40, or 80 μg), subcutaneous teriparatide (20 μg), or placebo for 24 weeks. TBS was measured from lumbar spine dual X-ray absorptiometry (DXA) images in 138 women for whom the DXA device was TBS software compatible. Assessments were made at baseline, 12 and 24 weeks. Between-group differences were assessed by generalized estimating equations adjusted for relevant baseline characteristics, and a pre-determined least significant change analysis was performed.

RESULTS

After 24 weeks, TBS increased significantly by 2.27, 3.14, and 4.21% versus baseline in participants on 20, 40, and 80 μg abaloparatide-SC daily, respectively, and by 2.21% in those on teriparatide (p < 0.05 for each). The TBS in the placebo group declined by 1.08%. The TBS increase in each treatment group was significantly higher than placebo at 24 weeks (p < 0.0001 for each) after adjustment for age, BMI, and baseline TBS. A dose-response was observed at 24 weeks across the three doses of abaloparatide-SC and placebo (p = 0.02). The increase in TBS in the abaloparatide-SC 80 μg group was significantly greater than TPTD (p < 0.03).

CONCLUSIONS

These results are consistent with an effect of abaloparatide-SC to improve lumbar spine skeletal microarchitecture, as assessed by TBS.

The Epidermolysis Bullosa Disease Activity and Scarring Index (EBDASI): grading disease severity and assessing responsiveness to clinical change in epidermolysis bullosa

BACKGROUND

The lack of validated outcome measures for epidermolysis bullosa (EB) presents major barriers to evaluating disease severity and comparing the efficacy of therapies. The Epidermolysis Bullosa Disease Activity and Scarring Index (EBDASI) was recently introduced as a valid and reliable instrument for EB; however, its interpretation for use in clinical practice and clinical trials is yet to be defined.

OBJECTIVE

To assess the interpretability of the EBDASI in classifying patients according to disease severity and clinical response.

METHODS

A total of 53 outpatients with EB at two interstate institutions were prospectively evaluated. At each visit, the principal dermatologist completed the EBDASI and global assessments of disease severity and change. Classifications for mild, moderate and severe disease using the EBDASI were determined using receiver operating characteristic curves. Minimal clinically important differences for the EBDASI activity subscale were calculated and compared with the standard error of measurement.

RESULTS

Total EBDASI score ranges of 0-42, 43-106 and 107-506 corresponded to mild, moderate and severe disease respectively. Reduction in EBDASI activity scores of greater than 9 indicated clinically significant improvement. An increase of 3 in the activity score indicated deterioration.

CONCLUSION

The EBDASI is a responsive tool and may be useful in characterizing disease severity and response. The cut-offs proposed in this study provide the first practical guide for interpreting the EBDASI, further supporting its use for longitudinal patient assessment and in clinical trials.

The reliability and validity of outcome measures for atopic dermatitis in patients with pigmented skin: A grey area

Background

Outcome measures for atopic dermatitis (AD) patients with pigmented skin have neither been developed nor validated.

Objective

To compare the reliability and validity of four common AD outcome measures in patients with various levels of skin darkness.

Method

The inter- and intra-rater reliability and construct validity of the EASI (Eczema Area and Severity Index), objective-SCORing Atopic Dermatitis (oSCORAD), Three Items Severity index (TIS) and Six Areas, Six Sites Atopic Dermatitis (SASSAD) were evaluated in 18 patients of various levels of skin darkness, using their full body photographs, by five trained clinicians.

Results

The inter-rater reliability intraclass coefficient (ICCs) and 95% confidence intervals were poor for highly pigmented patients: EASI -.054(-.200 to .657), oSCORAD -.089(-.206 to .598), TIS -.21(-.24 to .147), SASSAD -.071(-.200 to .631); fair for mildly pigmented patients: EASI .464(.140-.839), oSCORAD .588(.265-.89), TIS.524(.200-.865), SASSAD .41(.045-.775); and fair to good for non-pigmented patients: EASI .64(.330-.908), oSCORAD .586(.263-.889), TIS .403(.09-.809), SASSAD .667(.358-.916). Erythema likely contributed to the inter-rater variability. Construct validity had significant correlations across all measures in non-pigmented patients, but no correlations in highly pigmented patients.

Conclusion

AD outcome measures have poor reliability and validity in highly pigmented patients, with variations in erythema perception being a contributor.

“Orthogonal polarization spectral imaging”Eine neue klinische Methode für das Monitoring der Mikrozirkulation

The orthogonal polarization spectral (OPS) imaging technology is a new non-invasive method to directly visualize multiple conditions of the microcirculation which has several clinical applications in humans. Quantitative measurement of the diameter of vessels, the velocity of red blood cells and functional capillary density (FCD) can be made. Activation of leukocytes can be monitored and also quantified. A transdermal approach can be used in premature babies and neonates to view the microcirculation and has also been used experimentally to determine haemoglobin levels. The application to various surfaces and solid organs allows a variety of pathophysiologies and phases to be examined.

Desloratadine prevents compound 48/80-induced mast cell degranulation: visualization using a vital fluorescent dye technique

BACKGROUND

Desloratadine is a selective H1-antihistamine used in the treatment of allergic rhinitis and chronic idiopathic urticaria. Desloratadine inhibits the release of allergic inflammatory mediators in vitro. We studied the impact of desloratadine on mast cell degranulation due to activation and re-activation by the secretagogue, compound 48/80.

METHODS

Rat peritoneal eluate containing 5-6% mast cells were activated by a low concentration of compound 48/80 in a medium containing the vital fluorescent dye, Sulforhodamine-B (SFRM-B, 200 microg/ml), which is engulfed by activated mast cells. The fluorescent image of activated mast cells was captured digitally and the total fluorescent area was analyzed when desloratadine was applied before or after compound 48/80.

RESULTS

Mast cells were not activated by desloratadine (10(-4) M), SFRM-B (200 microg/ml), or diluent alone. A low concentration of compound 48/80 (0.125 microg/ml) induced fluorescence, while mast cells lost fluorescent images due to further degranulation on re-exposure to compound 48/80. Desloratadine (10(-8)-10(-4) M), inhibited compound 48/80-induced mast cell degranulation in a concentration-dependent manner. Desloratadine also reduced the loss of fluorescent images due to re-exposure to compound 48/80.

CONCLUSIONS

Desloratadine may have a mast cell stabilizing effect at low concentrations in response to repeated mast cell activation in vitro.

Characteristics of patients with seasonal allergic rhinitis and concomitant asthma

BACKGROUND

Allergic rhinitis and asthma often co-exist and appear to produce a continuum of airway disease, but whether the clinical characteristics of asthma in patients with seasonal rhinitis differ from those of persistent asthma has not been examined.

OBJECTIVE

The aim of this retrospective study was to characterize the clinical features of patients with seasonal allergic rhinitis with concomitant asthma and to compare them with those in patients with persistent asthma.

METHODS

The patient populations for this study were derived from nine prospective, placebo-controlled planned clinical trials of similar design. Six studies (958 patients) enrolled patients with seasonal allergic rhinitis and concomitant asthma; three (607 patients) involved patients with persistent asthma. In all studies, patients were excluded from oral corticosteroid therapy in the preceding 3 months, and from inhaled corticosteroids in the preceding month.

RESULTS

Patients with seasonal rhinitis and asthma had a significantly (P<0.001) higher total asthma symptom score than those with persistent asthma. In particular, cough was three times more severe. The need for beta(2)-agonist as a rescue medication and the ratio of forced expiratory volume in 1 s/forced vital capacity (FVC) were similar in the two groups whereas forced expiratory fraction 25-75%/FVC was significantly (P<0.02) reduced in the persistent asthmatics. Asthma and nasal symptom severity scores were correlated in patients with seasonal rhinitis and asthma (P<0.0001).

CONCLUSIONS

Patients with seasonal allergic rhinitis and concomitant asthma appear to differ from those with persistent asthma. A prospective study should be designed to discover whether patients with seasonal rhinitis and asthma may represent a distinct nosological entity, 'allergic airway disease'.

Comparison of the effects of desloratadine 5-mg daily and placebo on nasal airflow and seasonal allergic rhinitis symptoms induced by grass pollen exposure

BACKGROUND

Nasal congestion is a chronic symptom of seasonal allergic rhinitis (SAR) that is often difficult to treat with antihistamines. Desloratadine, a new, potent, H1-receptor antagonist has been shown to decrease nasal congestion in clinical trials and to maintain nasal airflow in response to grass pollen exposure. We compared the effects of desloratadine 5 mg and placebo on nasal airflow, nasal secretion weights and SAR symptoms, including nasal congestion, in patients exposed to grass pollen in an environmental exposure unit.

METHODS

Forty-six grass pollen allergic SAR patients received desloratadine or placebo for 7 days, followed by a 10-day washout, and then crossed over to the other treatment for 7 days. A 6-h allergen exposure was performed at the end of each treatment period.

RESULTS

Desloratadine was significantly superior to placebo in maintaining nasal airflow (P <or= 0.014) and lessening the increase in nasal secretion weights (P < 0.001) throughout allergen exposure. SAR symptom scores, including nasal congestion, were significantly less with desloratadine than placebo (P <or= 0.001). Desloratadine was well tolerated.

CONCLUSIONS

This study confirms that, compared with placebo, desloratadine can maintain nasal airflow and reduce nasal secretion weights and the severity of SAR symptoms, including nasal congestion, in SAR patients exposed to grass pollen allergen.

Orthogonal polarisation spectral imaging as a new tool for the assessment of antivascular tumour treatment in vivo: a validation study

Tumour angiogenesis plays a key role in tumour growth, formation of metastasis, detection and treatment of malignant tumours. Recent investigations provided increasing evidence that quantitative analysis of tumour angiogenesis is an indispensable prerequisite for developing novel treatment strategies such as anti-angiogenic and antivascular treatment options. Therefore, it was our aim to establish and validate a new and versatile imaging technique, that is orthogonal polarisation spectral imaging, allowing for non-invasive quantitative imaging of tumour angiogenesis in vivo. Experiments were performed in amelanotic melanoma A-MEL 3 implanted in a transparent dorsal skinfold chamber of the hamster. Starting at day 0 after tumour cell implantation, animals were treated daily with the anti-angiogenic compound SU5416 (25 mg kg x bw(-1)) or vehicle (control) only. Functional vessel density, diameter of microvessels and red blood cell velocity were visualised by both orthogonal polarisation spectral imaging and fluorescence microscopy and analysed using a digital image system. The morphological and functional properties of the tumour microvasculature could be clearly identified by orthogonal polarisation spectral imaging. Data for functional vessel density correlated excellently with data obtained by fluorescence microscopy (y=0.99x+0.48, r2=0.97, R(S)=0.98, precision: 8.22 cm(-1) and bias: -0.32 cm(-1)). Correlation parameters for diameter of microvessels and red blood cell velocity were similar (r2=0.97, R(S)=0.99 and r2=0.93, R(S)=0.94 for diameter of microvessels and red blood cell velocity, respectively). Treatment with SU5416 reduced tumour angiogenesis. At day 3 and 6 after tumour cell implantation, respectively, functional vessel density was 4.8+/-2.1 and 87.2+/-10.2 cm(-1) compared to values of control animals of 66.6+/-10.1 and 147.4+/-13.2 cm(-1), respectively. In addition to the inhibition of tumour angiogenesis, tumour growth and the development of metastasis was strongly reduced in SU5416 treated animals. This new approach enables non-invasive, repeated and quantitative assessment of tumour vascular network and the effects of antiangiogenic treatment on tumour vasculature in vivo. Thus, quantification of tumour angiogenesis can be used to more accurately classify and monitor tumour biologic characteristics, and to explore aggressiveness of tumours.

Comparison of regional blood flow values measured by radioactive and fluorescent microspheres

Fluorescent microspheres (FM) have become an attractive alternative to radioactive microspheres (RM) for the measurement of regional blood flow (RBF). The aim of the present study was to investigate the comparability of both methods by measuring RBF with FM and RM. Eight anaesthetised pigs received simultaneous, left atrial injections of FM and RM with a diameter of 15 microm at six different time points. Blood reference samples were collected from the descending aorta. RBF was determined in tissue samples of the myocardium, spleen and kidneys of all 8 animals. After radioactivity of the tissue samples was determined, the samples were processed automatically for measuring fluorescence using a recently developed filter device (SPU). RBF was calculated with both the isotope and spectrometric data of both methods for each sample resulting in a total of 10,512 blood flow values. The comparison of the RBF values yielded high linear correlation (mean r(2) = 0.95 +/- 0.03 to 0.97 +/- 0.02) and excellent agreement (bias 5.4-6.7%, precision 9.9- 16.5%) of both methods. Our results indicate the validity of MS and of the automated tissue processing technique by means of the SPU.

Validation of OPS imaging for microvascular measurements during isovolumic hemodilution and low hematocrits

Orthogonal polarization spectral (OPS) imaging is a new technique that can be used to visualize the microcirculation with reflected light. It uses hemoglobin absorption to visualize the red blood cells (RBCs). Thus the method could fail at low hematocrit (Hct). The aim of this study was to validate OPS imaging for quantitative measurements of diameter and functional capillary density (FCD) under conditions of hemodilution of varying degrees to achieve a wide range of Hcts. The validation was performed in the dorsal skinfold chamber of nine awake Syrian golden hamsters. Measurements of vessel diameter and FCD were performed off-line using Cap-Image on video sequences captured using OPS imaging and standard intravital fluorescence microscopy at baseline, 85, 70, 55, and 40% of the initial Hct. For hemodilution, isovolumic exchange of blood for 6% Dextran 60 was performed. Bland-Altman plots for the vessel diameter and FCD show good agreement between the two methods for both parameters at all studied Hcts. As expected, there was a systematic bias of approximately 4 microm in the diameter measurements since the RBC column was measured and not the intravascular diameter. In conclusion, OPS imaging can be used to measure diameter and FCD at a wide range of Hcts.

In vivo monitoring of microvessels in skin flaps: introduction of a novel technique

Orthogonal polarization spectral (OPS) imaging was validated against intravital fluorescence microscopy (IFM) for microvascular measurements in skin flaps of hairless mice. Examinations were performed 1, 6, and 24 hours after elevation (n = 8) with both OPS imaging and IFM. A fluorescent dye was a prerequisite for IFM measurements but not for OPS imaging. Our findings show that OPS imaging can visualize the skin flap microcirculation independent from the application of fluorescent tracers. From these images, quantitative analysis of functional capillary density (FCD) was feasible. As expected, FCD was significantly lower in the distal part of the flap compared with its base (171.8 +/- 34.7 versus 62.0 +/- 25.6, mean +/- SD; 1 hour data). Comparison of OPS imaging and IFM revealed a significant correlation of FCD values (P < 0.001) at all time points. Given the success of this validation study on mouse skin flaps, clinical investigations will have to prove that OPS imaging can also successfully be used to monitor flaps in humans.

Assessing the microcirculation in a burn wound by use of OPS imaging

We report on the use of OPS imaging to visualize the microcirculation in a burn wound. This novel technique produces high quality images of the microcirculation and quantitative analysis of functional capillary density (FCD) was possible. FCD measured at day 3 following the injury was 11.2 +/- 4.6 (n/mm superset2; mean +/- SEM). During the initial phase of healing microcirculatory changes were characterized by a moderate but steady increase of FCD, which showed marked increase beginning from day 12 following the burn (16.6 +/- 6.9). Maximal FCD measured at day 23 (48.2 +/- 19.7) decreased from this point in time to finally reach 25.2 +/- 10.3 n/mm superset2 at the end of observation. OPS imaging allows for direct in vivo visualization and quantification of the microcirculation in burned skin. Our results of the use of OPS imaging in assessing the microcirculation in a burn wound appear promising, and we hope that this novel technique will allow to improve the knowledge of the dynamics of the microcirculation in the pathophysiology of thermal injury.

Orthogonal polarization spectral imaging as a tool for the assessment of hepatic microcirculation: a validation study

BACKGROUND

Quantitative analysis of liver microcirculation using intravital fluorescence microscopy in animals has increased our knowledge about ischemia-reperfusion injury. However, because of the size of the instrumentation and the necessity of fluochromes for contrast enhancement, human liver microcirculation cannot be observed. Orthogonal Polarization Spectral (OPS) imaging is a recently introduced technique that can be used to visualize the microcirculation without the need for fluorescent dyes. It is a small, hand-held device and could potentially be used to study the microcirculation of the human liver in a clinical setting. However, before implementation into clinical use its ability to quantitatively measure microcirculatory parameters must be validated.

METHODS

The livers of Spraque-Dawley rats (n=9) were exteriorized, and images were obtained using OPS imaging and intravital fluorescence microscopy of the identical microvascular regions before and after the induction of a 20-min warm lobar ischemia. Images were videotaped for later computer-assisted off-line analysis.

RESULTS

OPS imaging can be used to accurately quantify the sinusoidal perfusion rate, vessel diameter, and venular red blood cell velocity. Correlation parameters were significant and Bland-Altman analyses showed good agreement for data obtained from the two methods at baseline as well as during reperfusion.

CONCLUSION

OPS imaging can be used to quantitatively measure microcirculatory parameters in the rat liver under both physiological and pathophysiological conditions. Thus, OPS imaging has the potential to be used to make quantitative measurements of the microcirculation in the human liver.

The Cytoscan Model E-II, a new reflectance microscope for intravital microscopy: comparison with the standard fluorescence method

The Cytoscan Model E-II (Cytometrics Inc., Philadelphia, Pa., USA) is a newly developed instrument which functions as an intravital microscope and is small and easily portable. Through the use of orthogonal polarization spectral (OPS) imaging, the Cytoscan Model E-II delivers images of the microcirculation which are comparable to those achieved with intravital fluorescence videomicroscopy (IFM), but without the use of fluorescent dyes. The purpose of this study was to validate the Cytoscan Model E-II instrument against IFM. The experiments were carried out on striated muscle in the dorsal skinfold chamber of the awake Syrian hamster. The following parameters were measured in identical regions of interest in the same animal under baseline conditions and 0.5 and 2 h after a 4-hour period of pressure-induced ischemia: arteriolar diameter, venular diameter and venular red blood cell velocity. Bland-Altman plots showed good agreement between the two techniques for venular red blood cell velocity. As expected, arteriolar and venular diameters as measured by the Cytoscan were on average 5 microm smaller than the values from IFM, since the Cytoscan measures the red blood cell column width and IFM measures luminal diameter. Thus, OPS imaging can be used to make valid measurements of microvascular diameter and red blood cell velocity in tissues.

Characterization and prevention of phototoxic effects in intravital fluorescence microscopy in the hamster dorsal skinfold model

Intravital microscopy is widely used to study the microcirculation. However, the use of fluorescent dyes can induce phototoxic effects which may affect the measurements, particularly in tissue exposed to oxidative stress. The aim of the study was to determine the threshold light dose at which fluorescent microscopy is associated with phototoxic effects in the hamster dorsal skinfold chamber under normal and pathological conditions. The extent of phototoxicity in the microcirculation in the hamster skinfold chamber was investigated using intravital fluorescent microscopy during 60 min of illumination (1048 mW/cm2) applying two different concentrations of fluorescein isothiocyanate dextran under baseline conditions (groups A and B) and following 4 h of ischemia (groups C and D). In the second part of the study the microvasculature was analyzed regarding phototoxic effects during a standardized intravital microscopic examination after 4 h of pressure induced ischemia. Groups I and II (n=7) were studied using epiillumination after injection of fluorescein isothiocyanate dextran plus rhodamine 6G or rhodamine 6G only. In group III (n=7) only transillumination was used. Arteriolar vasospasm, microvascular perfusion failure, thrombus formation, and enhanced leukocyte endothelium interaction were observed as signs of a phototoxic effect in normal tissue. However, the light doses needed to induce these effects clearly exceeded those during standard examinations. The induction of a 4-h ischemia and reperfusion further enhanced these effects. Despite the predamage by ischemia/reperfusion the comparison of epiillumination and transillumination microscopy using a standard protocol showed no differences regarding the parameters analyzed at any time. This indicates that epiillumination and the fluorescent dyes per se did not affect the experimental results. These results show that ischemia/reperfusion studies in the dorsal skinfold chamber of the Syrian golden hamster can be carried out safely without the risk of inducing phototoxic effects by fluorescent microscopy. Nevertheless every laboratory using epiillumination and fluorescent dyes should take precautions to avoid these effects by the use of sensitive cameras to lower the light dose.

Sustained reduction of exercise perfusion defect extent and severity with isosorbide mononitrate (Imdur) as demonstrated by means of technetium 99m sestamibi

BACKGROUND

The impact of long-acting nitrates on the extent and severity of stress-induced myocardial ischemia is not well described, especially after long-term treatment.

METHODS

Forty patients with chronic stable angina and reversible ischemia on an exercise stress myocardial perfusion single photon emission computed tomography (ex-SPECT) were prospectively studied in a 6-week period. At baseline, rest thallium-201/exercise stress technetium 99m sestamibi SPECT was performed, followed by treatment with extended-release isosorbide 5-mononitrate (5-ISMN, Imdur). Follow-up ex-SPECT was performed 5 days and 6 weeks after the initiation of therapy with extended-release 5-ISMN. The exercise treadmill testing (ETT) protocol and exercise duration of the follow-up studies were the same as that of the baseline ETT. Defect extent and severity were analyzed both by means of an automated quantitative method, with CEqual software, and visually, with a 20-segment scoring system (which was also used to derive a summed stress score [SSS]).

RESULTS

In the 6-week study period, significant reductions occurred in both the extent and the severity of exercise-induced ischemia by means of quantitative SPECT (13.8% [P<.0003] and 12.7% [P<.0003], respectively). There was no significant change in these variables between stages 2 (day 5) and 3 (6 weeks), indicating no development of tolerance to the nitrate effect. Similar reductions were noted by means of the visual analysis (SSS reduction of 13.0% [P<.002]) in the entire study period.

CONCLUSIONS

Patients with chronic-stable-angina treated with a long-acting nitrate demonstrate improvement in myocardial perfusion defect extent and severity in an extended period by means of both visual and quantitative analysis of sequential exercise testing to the same rate-pressure product end point.

Efficacy and tolerability of loratadine versus fexofenadine in the treatment of seasonal allergic rhinitis: a double-blind comparison with crossover treatment of nonresponders

BACKGROUND

Nonsedating antihistamines are well-established treatment for seasonal allergic rhinitis (SAR), but patients do not always respond to the first antihistamine prescribed.

OBJECTIVE

This double-blind, double-dummy, randomized, 2-phase, multicenter study was designed primarily to compare the therapeutic responses to loratadine and fexofenadine in patients who failed initial therapy with the other drug.

METHODS

Male and female patients aged 12 to 60 years received loratadine 10 mg once daily (n = 331) or fexofenadine 60 mg twice daily (n = 328) for 14 days (phase 1); nonresponders (ie, those who had <25% reduction in the sum of 5 SAR symptoms rated by the investigator on a 4-point scale) subsequently received the alternate medication for 14 days (phase 2). The investigator's rating of relief (complete, marked, moderate, or slight relief of symptoms or treatment failure) at the end of phase 2 was the primary efficacy measure; changes in total symptom severity (TSS) assessed by the investigator (4-point scale) and the patient (11-point visual analog scale) were secondary measures.

RESULTS

Mean decreases in TSS were significantly greater with loratadine than with fexofenadine for the 659 patients who completed phase 1 (-12.7 vs -10.2, respectively; P = 0.019; patient assessment) and for the 389 patients who responded to initial therapy (-6.6 vs -6.1, respectively; P = 0.037; investigator assessment). Of the 389 patients who responded to initial therapy, 61.0% had received loratadine and 57.0% had received fexofenadine. More nonresponders to initial therapy had moderate, marked, or complete relief of symptoms after switching to loratadine than after switching to fexofenadine (62.4% vs 51.2%, respectively; P = 0.005) and treatment failure in 10.6% vs 21.7%, respectively (P = 0.011).

CONCLUSION

Overall, ioratadine provided significantly better therapeutic response than fexofenadine in patients who failed to respond to initial therapy with the other drug.

Use of digoxigenin-labelled ampicillin in the identification of penicillin-binding proteins in Helicobacter pylori

Amoxycillin is used in current therapeutic regimens to treat the infection caused by the human gastric pathogen, Helicobacter pylori. The penicillin-binding proteins (PBPs) are the primary targets for the beta-lactam antibiotics, such as amoxycillin, and are involved in the terminal stages of peptidoglycan synthesis. They also play active roles in the determination and maintenance of cellular morphology. It was believed that an organism with a complex morphology, such as H. pylori, would have more than the three PBPs previously suggested. Using digoxigenin-labelled ampicillin (DIG-ampicillin), we report the identification of eight PBPs in H. pylori with masses of 72, 62, 54, 50, 44, 33.5, 30.5 and 28 kDa. A smaller (21 kDa) ninth band was also detected, which may represent another PBP. However, the relatively small size of this apparent PBP raises questions as to whether this is a true PBP. In an attempt to identify the PBPs to which amoxycillin preferentially binds, amoxycillin was used in competition assays with DIG-ampicillin. It appeared that amoxycillin inhibited the binding of DIG-ampicillin to only the 72 kDa PBP. The experimental data were also compared with the seven putative PBPs identified in the two published H. pylori genomes, most of which correlate with the experimental data. To investigate further the properties of these PBPs, the seven putative PBP genes identified in the H. pylori genomes were examined. The derived amino acid sequences of the putative PBPs were examined for the three characteristic motifs found in all conventional PBPs, SXXK, SXN and KTG. We were able to determine that all of the putative PBPs had at least one of these motifs, but none possessed all three motifs with the characteristics of conventional PBPs. These findings suggest that the PBPs of H. pylori are unique.

Automation of the use of fluorescent microspheres for the determination of blood flow

Fluorescent-labeled microspheres (FM) are a new tool for the determination of organ blood flow. However, the FM-method is labor intensive, because of the necessity to recover the microspheres from the tissue samples. The aim of this study was to automate the FM-method. A Zymate-Robotic System (Zymark, Idstein, Germany) was modified to handle a novel filtration device. The robot is surrounded by 12 different stations which are necessary to process the samples. It performs the sequential steps which are needed to recover the microspheres from the samples. The dyes are finally released from the FM with a solvent and their fluorescent intensity is measured online using a spectrophotometer (Perkin Elmer, Uberlingen, Germany). The robotic system is able to recover the FM through digestion and filtration of the tissue samples using the new filter, to dissolve the FM and to release the dyes so that their fluorescent intensities can be measured for the calculation of organ blood flow.

Implementation of the microdialysis method in the hamster dorsal skinfold chamber

The aim of this study was to implement the microdialysis method, a well-established technique for measuring the local concentration of neurotransmitters and metabolites in the brain, in the dorsal skinfold chamber of the awake hamster. First, the effects of implanted, nonperfused microdialysis probes on the microcirculation were examined. Skinfold chambers were prepared with and without probes. Two and 3 days later, the following parameters were assessed: diameter, red blood cell (RBC) velocity, macromolecular leakage, leukocyte rolling fraction, and adherent leukocytes in venules, diameter and macromolecular leakage in arterioles, and functional capillary density (FCD). No significant differences between the animals of the two groups were observed in any of the parameters on either day. Second, the interstitial lactate concentration was measured at two perfusion rates in groups with and without a 4-h tourniquet ischemia. The induction of ischemia resulted in a significant increase in lactate concentration over the control values in the tissue within 1 h to 8000 +/- 860 microM, where it remained until the reperfusion, at which point the concentration returned to control values within 1 h. The microdialysis method provides the opportunity to measure the concentration of metabolites in the extravascular space of the hamster dorsal skinfold chamber.

In vivo assessment of synovial microcirculation and leukocyte-endothelial cell interaction in mouse antigen-induced arthritis

OBJECTIVE

The microcirculation and leukocyte-endothelial cell interaction in synovial tissue of an inflamed joint are known to play a crucial role in the pathogenesis of rheumatoid arthritis. The aim of this study was to characterize the in vivo changes in the microvasculature and in leukocyte-endothelial cell interactions in the mouse synovial tissue using intravital fluorescence microscopy in three stages of antigen-induced arthritis. The expression of E- and P-selectin and ICAM-1 were also studied using immunohistochemistry.

METHODS

Antigen-induced arthritis (AiA) was produced in Balb/c mice. The severity of arthritis at three different phases was quantified using a clinical and histological score. For the intravital fluorescence microscopy measurements, the patella tendon was partially resected for visualization of the intraarticular synovial tissue of the knee joint. The number of rolling and adherent leukocytes, functional capillary density (FCD) and RBC velocity were quantitatively measured in synovial microvessels. Expression of ICAM-1, E- and P-selectin was assessed by immunohistochemistry.

RESULTS

There was a significant increase in the leukocyte rolling fraction in postcapillary venules in the acute phase of AiA (from 0.26 +/- 0.05 in controls to 0.45 +/- 0.04 8 d after AiA induction). The number of leukocytes adherent to the endothelium was significantly elevated in all phases of arthritis (from 121 +/- 27 in controls to 376 +/- 62 mm2 63 d after AiA-induction). Functional capillary density was significantly enhanced in the acute (332 +/- 15 cm/cm2) and intermediate phases (320 +/- 15 cm/cm2) compared to control values (227 +/- 15 cm/cm2). Arthritis resulted in a distinct increase in the expression of ICAM-1 on the synovial endothelium in all phases of AiA. E- and P-selectin expression were detected only in the acute phase.

CONCLUSION

Our model provides new insights into the microcirculatory changes which occur in the synovial tissue of an arthritic joint.