Horismenus camobiensis (Hym.: Eulophidae), a new hyperparasitoid of Cotesia invirae (Hym.: Braconidae) in Opsiphanes invirae (Lep.: Nymphalidae) pupae

Abstract Horismenus camobiensis sp. nov. (Hymenoptera: Eulophidae), is described based on morphological, molecular and ecological data; this new species of chalcid wasp acts as hyperparasitoid of Opsiphanis invirae (Hübner, 1818) (Lepidoptera: Nymphalidae) in its parasitoid Cotesia invirae Salgado-Neto and Whitfield, 2019 (Hymenoptera: Braconidae). Diagnoses with morphological and molecular characters and illustrations are provided.

Infrastructural considerations of implementing gene therapy for hemophilia in the Nordic context

Background

Despite improvements in hemophilia care, challenges remain, including treatment burden and impaired quality of life. Gene therapy may overcome these. However, its introduction presents a challenge.

Objectives

To outline a function-based gene therapy working model describing critical milestones associated with gene therapy handling, administration, and follow-up to facilitate and implement an effective infrastructure for gene therapy introduction.

Design

Literature review and consensus discussion among Hemophilia Comprehensive Care centers (HCCCs) in the Nordic region.

Methods

Representatives from six HCCCs sought to pinpoint milestones and key stakeholders for site readiness at the pre-, peri-, and post-infusion stages, including authority and genetically modified organism (GMO) product requirements, awareness, medical eligibility, logistics and product handling for infusion, laboratory monitoring, and follow-up.

Results

A gene therapy transit map was developed with key stakeholders identified. The approach to prepare the vector will differ between the Nordic centers, but the contracted pharmacy unit will be a key stakeholder. Therefore, a pharmacy checklist for the implementation of gene therapy was developed. For the future, Advanced Therapy Medicinal Product centers will also be implemented. Patients' expectations, commitments, and concerns need to be addressed repeatedly and education of patients and the expanded health-care professionals team will be the key to successful and optimal clinical management. Eligibility testing according to the product's summary of product characteristics and frequent follow-up and monitoring post-infusion according to the World Federation of Hemophilia chart will be crucial.

Conclusion

The approach to deliver gene therapy in the Nordic region will differ partly between the hemophilia centers, but the defined road map with checklists for the implementation of this advanced therapy will be applicable to all. The map may also serve as a platform for the use of future GMO product options both within and outside the area of hemophilia.

Tr1 cell-mediated protection against autoimmune disease by intranasal administration of a fusion protein targeting cDC1 cells

Curative therapies against autoimmune diseases are lacking. Indeed, most of the currently available treatments are only targeting symptoms. We have developed a novel strategy for a therapeutic vaccine against autoimmune diseases based on intranasal administration of a fusion protein tolerogen, which consists of a mutant, enzymatically inactive, cholera toxin A1 (CTA1)-subunit genetically fused to disease-relevant high-affinity peptides and a dimer of D-fragments from protein A (DD). The CTA1 R7K mutant - myelin oligodendrocyte glycoprotein (MOG), or proteolipid protein (PLP) - DD (CTA1R7K-MOG/PLP-DD) fusion proteins effectively reduced clinical symptoms in the experimental autoimmune encephalitis model of multiple sclerosis. The treatment induced Tr1 cells, in the draining lymph node, which produced interleukin (IL)-10 and suppressed effector clusters of differentiation 4+ T-cell responses. This effect was dependent on IL-27 signaling because treatment was ineffective in bone marrow chimeras lacking IL-27Ra within their hematopoietic compartment. Single-cell RNA sequencing of dendritic cells in draining lymph nodes demonstrated distinct gene transcriptional changes of classic dendritic cells 1, including enhanced lipid metabolic pathways, induced by the tolerogenic fusion protein. Thus, our results with the tolerogenic fusion protein demonstrate the possibility to vaccinate and protect against disease progression by reinstating tolerance in multiple sclerosis and other autoimmune diseases.

Risk factors for suicide in bipolar disorder: a cohort study of 12 850 patients

OBJECTIVE

Bipolar disorder carries a high risk of suicide. Identification of risk factors is important. The aim of this study was to study risk factors for suicide in a large cohort of men and women with bipolar disorder.

METHOD

A prospective cohort study using clinical data from the Swedish National Quality Register for Bipolar Affective Disorder (BipoläR). The outcome variable was suicide captured in the Cause of Death Register between 2004 and 2014. Hazard ratios (HR) were calculated using Cox proportional hazards models.

RESULTS

Of 12 850 persons (4844 men and 8006 women) with bipolar disorder, 90 (55 men and 35 women) died by suicide during the follow-up period (between 1 and 10 years). Male sex (HR 2.56), living alone (HR 2.45), previous suicide attempts (HR 4.10), comorbid psychiatric disorder (HR 2.64), recent affective episodes (HR 2.39), criminal conviction (HR 4.43), psychiatric inpatient care (HR 2.79), and involuntary commitment (HR 3.50) were significant risk factors for suicide. Several of the statistically significant risk factors for suicide in bipolar disorder differed between men and women.

CONCLUSIONS

Risk factors for suicide in bipolar disorder include factors associated with suicide in general, but also diagnosis-specific factors.

Frequency of Isolated Superficial Venous Incompetence in Patients with Venous Ulcers as Measured by Ambulatory Strain-Gauge Plethysmography

Objective:

Identification of isolated superficial venous incompetence (SVI) in patients with clinically diagnosed venous leg ulcers using a computerized strain-gauge plethysmograph.

Design:

Ambulatory leg ulcer patients were assessed as to the clinical diagnosis. Diagnoses other than venous ulceration were excluded.

Setting:

Department of Dermatology, Sahlgrenska Hospital, Göteborg, Sweden.

Patients:

One hundred and fourteen patients (133 legs) with venous leg ulcers were investigated.

Main outcome measures:

All patients were also investigated by measuring systolic ankle and arm pressure measurements. The ankle/arm (AI) was below 0.9 in 22 of the 133 ulcerated legs.

Results:

Of the 111 ulcerated legs with an AI>0.9, 10% had an isolated SVI.

Conclusions:

Isolated SVI is an important cause of venous leg ulcer development. Strain-gauge plethysmography is an inexpensive screening method, and is easy to use. Further examination with the more exact, but also more expensive and time-consuming, colour duplex should be performed in selected cases.

Feeding transgenic plants that express a tolerogenic fusion protein effectively protects against arthritis

Although much explored, oral tolerance for treatment of autoimmune diseases still awaits the establishment of novel and effective vectors. We investigated whether the tolerogenic CTA1(R7K)-COL-DD fusion protein can be expressed in edible plants, to induce oral tolerance and protect against arthritis. The fusion protein was recombinantly expressed in Arabidopsis thaliana plants, which were fed to H-2(q) -restricted DBA/1 mice to assess the preventive effect on collagen-induced arthritis (CIA). The treatment resulted in fewer mice exhibiting disease and arthritis scores were significantly reduced. Immune suppression was evident in treated mice, and serum biomarkers for inflammation as well as anticollagen IgG responses were reduced. In spleen and draining lymph nodes, CD4(+) T-cell responses were reduced. Concomitant with a reduced effector T-cell activity with lower IFNγ, IL-13 and IL-17A production, we observed an increase in IL-10 production to recall antigen stimulation in vitro, suggesting reduced Th1, Th2 and Th17 activity subsequent to up-regulated IL-10 and regulatory T-cell (Treg) functions. This study shows that edible plants expressing a tolerogen were effective at stimulating CD4 T-cell tolerance and in protecting against CIA disease. Our study conveys optimism as to the potential of using edible plants for oral treatment of rheumatoid arthritis.

A specific tolerance inducing vector for therapeutic treatment of autoimmune diseases (THER5P.842)

We have developed a novel platform for intranasal treatment of autoimmune diseases in which ADP-ribosylation determines whether immunity or tolerance is induced. Hence, cholera toxin A1-subunit based immunomodulation through the CTA1-peptide-DD fusion protein promotes enhancement, while inactive mutants induce suppression. Whereas the target population after intranasal administration of both constructs was CD103+CD11blow DC’s, both active and inactive mutants induced strong CD4 T cell priming, but they differentially affected CD4 T cell differentiation. This way inactive mutant constructs generated regulatory CD4 T cells producing IL-10 and effectively preventing experimental autoimmune encephalitis (EAE) and collagen-induced arthritis (CIA), when carrying relevant peptides. Targeted DCs expressed low levels of CD80, CD86 and CD40, while, by contrast, ADP-ribosylating CTA1-peptide-DD constructs gave significantly enhanced co-stimulation. Suppression was global in that regulatory T cells following treatment were able to suppress adoptively transferred naïve CD4 T cells and could subsequently maintain tolerance. The use of specifically tolerance-inducing fusion proteins may be a way forward in the search of effective treatments against autoimmune diseases. The immunomodulating effect on the CD103+CD11blow DCs will be described and the requirement for CTA1-binding to Gsa evaluated in detail, using Cre-lox Gsa-deficient mice.

Central administration of ghrelin alters emotional responses in rats: behavioural, electrophysiological and molecular evidence

The orexigenic and pro-obesity hormone ghrelin targets key hypothalamic and mesolimbic circuits involved in energy balance, appetite and reward. Given that such circuits are closely integrated with those regulating mood and cognition, we sought to determine whether chronic (>2 weeks) CNS exposure to ghrelin alters anxiety- and depression-like behaviour in rats as well as some physiological correlates. Rats bearing chronically implanted i.c.v. catheters were treated with ghrelin (10 μg/d) or vehicle for 4 weeks. Tests used to assess anxiety- and depression-like behaviour were undertaken during weeks 3-4 of the infusion. These revealed an increase in anxiety- and depression-like behaviour in the ghrelin-treated rats relative to controls. At the end of the 4-week infusion, brains were removed and the amygdala dissected for subsequent qPCR analysis that revealed changes in expression of a number of genes representing key systems implicated in these behavioural changes. Finally, given the key role of the dorsal raphe serotonin system in emotional reactivity, we examined the electrophysiological response of dorsal raphe neurons after a ghrelin challenge, and found mainly inhibitory responses in this region. We demonstrate that the central ghrelin signalling system is involved in emotional reactivity in rats, eliciting pro-anxiety and pro-depression effects and have begun to explore novel target systems for ghrelin that may be of importance for these effects.

On the central mechanism underlying ghrelin's chronic pro-obesity effects in rats: new insights from studies exploiting a potent ghrelin receptor antagonist

In the present study, we explore the central nervous system mechanism underlying the chronic central effects of ghrelin with respect to increasing body weight and body fat. Specifically, using a recently developed ghrelin receptor antagonist, GHS-R1A (JMV2959), we investigate the role of GHS-R1A in mediating the effects of ghrelin on energy balance and on hypothalamic gene expression. As expected, in adult male rats, chronic central treatment with ghrelin for 14 days, when compared to vehicle-treated control rats, resulted in an increased body weight, lean mass and fat mass (assessed by dual X-ray absorptiometry), dissected white fat pad weight, cumulative food intake, food efficiency, respiratory exchange ratio and a decrease of energy expenditure. Co-administration of the ghrelin receptor antagonist JMV2959 suppressed/blocked the majority of these effects, with the notable exception of ghrelin-induced food intake and food efficiency. The hypothesis emerging from these data, namely that GHS-R1A mediates the chronic effects of ghrelin on fat accumulation, at least partly independent of food intake, is discussed in light of the accompanying data regarding the hypothalamic genes coding for peptides and receptors involved in energy balance regulation, which were found to have altered expression in these studies.

Larval therapy as a palliative treatment for severe arteriosclerotic gangrene on the feet

Larval therapy (LT) is known to be a gentle and effective method for removing necrotic tissue and bacteria and reducing the accompanying unpleasant odour. Ischaemia has been considered a relative contraindication for LT. We report a patient with ischaemia treated with LT. Inguinal revascularization was performed on a 69-year-old man with critical limb ischaemia, diabetes mellitus, heart failure and end-stage renal disease. Areas of dry black malodorous gangrene remained on the distal areas of the feet after surgery and the patient's poor health did not allow any additional surgery. The patient was referred to the dermatology department for LT. Although patients are usually given this treatment as inpatients, the patient requested treatment at home. After the first LT, there was a marked reduction in odour. The gangrene needed repeated applications of larvae to remove the dead tissue. After eight treatments, the result was more positive than we had expected, with total lack of odour and initiation of healing. Larvae cannot penetrate eschar, thus free-range larvae were used because they can move beneath the hard necrotic tissue and dissolve it.

The stability of 5-S-cysteinyldopa and 6-hydroxy-5-methoxyindole-2-carboxylic acid in human urine

5-S-cysteinyldopa and 6-hydroxy-5-methoxyindole-2-carboxylic acid are important intermediate metabolites in the formation of cutaneous melanin pigment. Since they both are serious candidates as markers of melanoma progression, their stability in urine has been investigated during storage at various conditions. The results show that storage at -20 degrees C is necessary. Both compounds are nonstable at room temperature, particularly if the urine was not acidified to pH 4-5. Reference levels were obtained from analysis of urine from 31 men and 40 women. The mean (SD) excretion of 5-S-cysteinyldopa was 32 (12.5) mumol/mol creatinine (women). Corresponding figures for 6H5MI2C were 23 (10.3) and 24 (8.1) mumol/mol creatinine for men and women respectively.

X-ray colour imaging

A prototype X-ray colour imaging system has been assembled using the principle of tomographic energy-dispersive diffraction imaging (TEDDI). The new system has been tested using samples of nylon-6, aluminium powder and deer antler bone. Non-destructive three-dimensional images of the test objects have been reconstructed on a 300 microm scale with an associated diffraction pattern at each voxel. In addition, the lattice parameters of the polycrystalline material present in the sampled voxels have been determined using full pattern refinement methods. The use of multiple diffracted parallel colour X-ray beams has allowed simultaneous spatially resolved data collection across a plane of the sample. This has simplified the sample scan motion and has improved data collection times by a factor scaling with the number of detector pixels. The TEDDI method is currently limited to thin samples (approx. 1-2mm) with light atoms owing to the very low detection efficiency of the silicon detector at X-ray energies above 25 keV. We describe how these difficulties can be removed by using semiconductor detectors made from heavier atomic material.

High-performance liquid chromatography analysis of rubber allergens in protective gloves used in health care

A high-performance liquid chromatography (HPLC) method developed for analysis of zinc dithiocarbamates was validated and used to perform a survey of disposable medical gloves used in southern Sweden. The gloves were extracted with acetone at room temperature for 10 min by shaking. The extracts were injected into a polyether ether ketone lined HPLC column, and peaks were analysed by a diode-array detector. The survey shows that of 19 gloves analysed, 10 contained zinc diethyldithiocarbamate (0.070-3.5 mg/g), 3 contained zinc pentamethylenedithiocarbamate (1.0-4.3 mg/g), 4 contained zinc dibutyldithiocarbamate (0.9-1.1 mg/g), and 2 contained 2-mercaptobenzothiazole (0.005-0.008 mg/g). None of them contained thiurams.

Adducts between nucleophilic amino acids and hexahydrophthalic anhydride, a structure inducing both types I and IV allergy

Haptens causing type I allergy have been shown to predominantly form lysine adducts in the carrier protein, while many haptens giving rise to type IV allergy preferentially form adducts with cysteine residues. Hexahydrophthalic anhydride derivatives are strong sensitizers capable of inducing allergic rhinitis, asthma and urticaria (type I allergy) and allergic contact dermatitis (type IV allergy). The ability of hexahydrophthalic anhydride (HHPA) to form adducts with nucleophilic amino acids and a model peptide in vitro is presented. Adduct formation was monitored by high-performance liquid chromatography with ultraviolet light/vis detection (LC-UV/vis) and high-performance liquid chromatography with mass spectrometric detection (LC/MS). The characterization was obtained by nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS and MS/MS). It was found that HHPA formed adducts with N(alpha)-acetylated lysine and cysteine and the non-acetylated alpha-amino group of proline and, to some extent, also with other nucleophilic amino acids. The adducts with lysine and proline were chemically stable. Addition of one HHPA to a model carrier peptide with all important nucleophilic amino acid residues showed N-terminal proline to be the major site of reaction. The addition of a second hapten gave a lysine adduct, but a minor cysteine adduct was also found. The cysteine-HHPA adducts were shown to be chemically unstable and participated in further reactions with lysine forming lysine-HHPA adducts. The results will be useful for understanding the formation of HHPA-protein adducts with the capability of being markers of exposure, and also to a deeper understanding of the chemical structures causing types I and IV allergy.

The evolution of host use and unusual reproductive strategies in Achrysocharoides parasitoid wasps

We studied host selection and exploitation, two crucial aspects of parasite ecology, in Achrysocharoides parasitoid wasps, which show remarkable host specificity and unusual offspring sex allocation. We estimated a molecular phylogeny of 15 Achrysocharoides species and compared this with host (plant and insect) phylogenies. This tri-trophic phylogenetic comparison provides no evidence for cospeciation, but parasitoids do show phylogenetic conservation of the use of plant genera. Patterns of sequence divergence also suggest that the parasitoids radiated more recently (or evolved much faster) than their insect hosts. Three main categories of brood production occur in parasitoids: (1) solitary offspring, (2) mixed sex broods and (3) separate (split) sex broods. Split sex broods are very rare and virtually restricted to Achrysocharoides, while the other types occur very widely. Our phylogeny suggests that split sex broods have evolved twice and provides evidence for a transition from solitary to mixed sex broods, via split sex broods, as predicted by theory.

Extraction of haptens from solid products and their delivery to the skin, exemplified by dithiocarbamates from rubber gloves

Allergic contact dermatitis is often caused by solid products such as rubber gloves. Patch testing with the product as is often gives negative results. Extraction of the haptens into an organic solvent is commonly performed to achieve a more correct investigation. The technique used for extraction of haptens from solid materials is only sporadically described. In this study, we investigated and optimized the yields of dithiocarbamates obtained by extraction from rubber gloves. The influence of solvent, extraction time and the procedures for extraction are evaluated. The delivery of zinc dibutyldithiocarbamate from the patch test preparation to the skin is determined.

HPLC analysis of alkyl thioureas in an orthopaedic brace and patch testing with pure ethylbutylthiourea

Ethylbutylthiourea (EBTU) is an accelerator used in the production of chloroprene (neoprene) rubber. EBTU occurs in a mixture with diethylthiourea (DETU) and dibutylthiourea (DBTU) in the accelerator. An analytical method originally developed for analysis of zinc dithiocarbamates in rubber has been used to analyse EBTU, DETU and DBTU in a knee brace responsible for an allergic contact dermatitis in a gardener suffering from arthrosis. EBTU was isolated and gave positive reactions when tested as a pure compound. The test reaction was accompanied by positive reactions to DETU and DBTU.

Larval therapy--an effective method of ulcer debridement

Since ancient times, larval therapy has been reputed to help wound healing. Its use has recently been rediscovered and it is now enjoying increasing interest in clinical practice, as well as in research. We have investigated the effects of larval therapy on wounds in an open study of 74 patients with necrotic or sloughy chronic ulcers of different aetiologies. We found larval therapy to effectively debride 86% of the necrotic ulcers, and a single application was clinically beneficial in two-thirds of the patients. Failure to debride was mostly attributable to larval death. No ulcer type was shown to be more suited to larval therapy than others; however, there was an excellent response in all 29 patients with diabetes. Larval therapy was also noted to reduce odour in 58% of the 31 foul-smelling ulcers of mixed aetiology. No serious side-effects were observed. One-quarter of the study group experienced less pain during treatment, while 41% felt no difference in pain, and, although 34% noted an increase in pain, most of these patients wanted to continue the treatment because of subjective and objective visual improvement in wound debridement. In conclusion, we found larval therapy to be effective for debriding ulcers, easy to use and well accepted by the patients.

Stereochemical considerations on concomitant allergic contact dermatitis to ester of the cis-trans isomeric compounds maleic acid and fumaric acid

Allergic contact dermatitis from esters of fumaric acid or esters of maleic acid is rare. The case of a chemist with allergic reactions to esters both of fumaric acid and of maleic acid is presented. Extremely high sensitivity of the patient to diethyl fumarate was noted. The formation of identical complete antigens from esters of these two cis-trans isomeric acids may be an explanation of the patient's double allergy. This is discussed from a stereochemical point of view. These stereochemical considerations point to a general mechanism where cis-trans isomeric alpha,beta-unsaturated carbonyl compounds are converted into the same complete antigen.

Reactivity of contact allergenic haptens to amino acid residues in a model carrier peptide, and characterization of formed peptide-hapten adducts

The type of chemical reaction between hapten and carrier protein in the formation of a complete antigen in vivo giving rise to an allergic contact dermatitis (ACD, type IV allergy) is essentially unknown. About 4000 low-molecular organic compounds are known to have allergenic properties. alpha,beta-Unsaturated carbonyl structures are frequently present among these compounds. Haptens giving rise to antibody formation and type I allergy have been shown to add predominantly to lysine in the carrier protein. In this paper, the reactivity of activated type IV haptens to a model peptide is reported. Essentially all amino acids with nucleophilic properties were present in the model peptide. Investigation of the relative reactivities of the amino acid residues to activated haptens under biomimetic conditions is performed in order to determine the proportions between the adducts of the different amino acid moieties. In all cases, the electrophilic alpha,beta-unsaturated haptens were found to be added to the cysteine residue and no lysine adduct was recorded. Nuclear magnetic resonance (NMR) spectroscopy was used to exclude steric hindrance of any amino acid residue in the addition reaction. The hapten-modified peptides were isolated and characterized by NMR and mass spectrometry.

Spontaneous formation of thiuram disulfides in solutions of iron(III) dithiocarbamates

Dithiocarbamates are used as pesticides and rubber additives. Dithiocarbamates are the reduced forms of thiuram disulfides and both of these groups of substances induce allergic contact dermatitis. The allergic cross-reactivity pattern between dithiocarbamates and thiurams is unclear. The aim of this study was to investigate why these cross-reactions occur sometimes but not always. HPLC-analysis of buffer solutions of iron(III) dithiocarbamates demonstrated that thiuram disulfides were formed spontaneously and rapidly in high yield. No such oxidation was observed in solutions of copper(II), zinc(II), or sodium dithiocarbamates. However, sodium diethyldithiocarbamate and zinc diethyldithiocarbamate were oxidized in buffer solution when ferric salt was added. The influence of different metal ions on the oxidation reaction is probably an explanation for the cross-reactivity patterns seen between dithiocarbamates and thiurams. These findings also show that careful handling is necessary in analytical and biological studies with solutions of iron(III) dithiocarbamates. Oxidation of dithiocarbamates in aqueous buffer at physiological pH has not been shown before.

Differential proteinase expression by Pseudomonas aeruginosa derived from chronic leg ulcers

Pseudomonas aeruginosa colonizes 20-30% of all venous leg ulcers. Hypothetically, P. aeraginosa could release proteases and cytotoxic substances in the environment of chronic ulcers, thus negatively affecting the wound-healing activity in this patient group. Here we show that P. aeruginosa isolates from leg ulcers exhibit a highly variable expression of the proteinases elastase and alkaline proteinase. We propose that bacterial phenotype should be taken into account in future studies on the clinical outcome of leg ulcers colonized by P. aeruginosa.

Stability of thiuram disulfides in patch test preparations and formation of asymmetric disulfides

The thiuram mix used in patch testing originally contains 4 compounds. However, chemical analysis of the test preparation revealed that several new compounds are spontaneously formed during storage. The structures of these compounds have been determined and the rate of their formation has been studied in buffer solution at pH 7.4. After a few hours, a large amount of mixed disulfides are formed in solutions originally containing only symmetric disulfides. The impact on the test result of the formation of asymmetric disulfides has been investigated by testing on thiuram-sensitive volunteers with different preparations of mixed thiuram disulfides. In our study, the formation of new asymmetric thiuram disulfides from the original symmetric thiuram disulfides in the test preparation had no influence on the result of the patch testing. However, as the chemical analysis showed that the mix composition changes during the period when the preparations are used, and differs between suppliers, the question is raised as to whether it is acceptable to use test preparations with a composition that is different from that labelled on the protocol.

Facial profile and dental changes before, during and after treatment with Hansaplate/Headgear

In this prospective study the changes of facial profile and dentition in 19 boys and 19 girls treated for 1 year with Hansaplate/Headgear were analyzed yearly over a 4-year period. On average the boys were 10.2 and the girls 9.2 years old at the first recording, i.e., 1 year pretreatment. The actual values are compared with standard growth data presented by Bathia and Leighton (1993). Irrespective of the initial face morphology, the Hansaplate/Headgear appliance straightened the facial hard and soft tissue profiles favorably. The upper lip became more retruded while the lower lip was unaffected by therapy. During the 2-year post-treatment period these changes continued, probably as a consequence of growth. The overjet was reduced by 5 mm during treatment and was found to be quite stable 2 years after treatment.

Tyrosinase-mediated formation of a reactive quinone from the depigmenting agents, 4-tert-butylphenol and 4-tert-butylcatechol

Exposure of the skin to certain phenols or catechols such as 4-tert-butylphenol (TBP) and 4-tert-butylcatechol (TBC) may cause leukoderma. These substances are used in the polymer industry and numerous cases have been reported. Several theories of the mechanism for chemical leukoderma have been suggested. In the present study, TBP and TBC are shown to be oxidised by tyrosinase. The oxidation of TBC yields a quinone that is further investigated on its reactions with cysteine or glutathione (GSH). The products formed are isolated and identified by mass spectrometry and nuclear magnetic resonance as being 4-tert-butyl-6-S-cysteinylcatechol (cys-TBC) and 4-tert-butyl-6-S-glutathionylcatechol (GS-TBC). The reactive quinone is a strongly electrophilic substance that rapidly reacts with GSH. A depletion of the GSH defence system may give conditions where the quinone lives long enough to effect its toxic properties. The influence of the reactive tert-butylquinone on enzymatic activities is demonstrated by the inhibition of glyceraldehyde-3-phosphate dehydrogenase.

Activation and cross-reactivity pattern of a new allergen in adhesive plaster

N,N'-disalicylidene-1,2-diaminopropane is a copper inhibitor present in some adhesive plasters, rubber products and gasoline. Upon contact with water it is hydrolyzed to salicylaldehyde and 1,2-diaminopropane. All patients in this study showed positive patch-test reactions to N,N'-disalicylidene-1,2-diaminopropane, and also to 1,2-diaminopropane and ethylenediamine. None reacted to salicylaldehyde. Patch testing with different N,N'-disalicylidene-derivatives showed localization of the amino groups in positions 1 and 2 to be a prerequisite of cross-reactivity to 1,2-diaminopropane and ethylenediamine. An extraction procedure and a high-performance liquid chromatography (HPLC) method for the analysis of adhesive plasters is described. Studies of the hydrolysis of the copper inhibitor at physiological pH showed rapid formation of 1,2-diaminopropane under biomimetic conditions.

[Infections and treatment of chronic leg ulcers: the use of antibiotics is too excessive, restrictive prescription is recommended]

Chronic venous leg ulcers are contaminated or colonised with bacteria that seldom affects ulcer healing. Signs of clinical infection appear in only a minority of chronic ulcers. In spite of this, data show a high consumption of antibiotics in this group of patients. Treatment with antibiotics is indicated only when clinical signs of infection or obvious risk factors are present or when Streptococcus pyogenes is isolated from the ulcer. In these cases an oral antistaphylococcal agent (semisynthetic penicillinase-resistant penicillin or first generation oral cephalosporin) is recommended as the first choice. Enterococci, anaerobic bacteria and gram-negative bacteria including pseudomonas spp. often colonise chronic ulcers, but do not usually cause antibiotic requiring infection.

[Iodine-induced hyperthyroidism after cadexomer iodine treatment of leg ulcers]

The article consists in two case reports of eldery patients who developed hyperthyroidism after cadexomer iodine treatment of small leg ulcers. The first was an 87-year-old woman who developed anxiety, hoarseness and tachycardia after five months treatment of a 12 cm2 leg ulcer with 350 g cadexomer iodine. Her serum level of free thyroxine (FT4) was 23.1 pmol/l (normal range, 11.7-28.0), and that of thyroid-stimulating hormone (TSH) 0.01 mIU/l (normal range, 0.1-3.0). She had had a nodular goitre for thirty years. The second was an 86- year-old woman who developed depression and confusion after three months' treatment of an 8 cm2 leg ulcer with 170 g cadexomere iodine. Her serum level of FT4 was 30.0 pmol/l, and that of TSH 0.005 mIU/l. Both patients underwent Tc99m pertechnetate scanning and iodine uptake measurement with a view to treating the hyperthyroidism with radio-iodine. However, as iodine uptake was inhibited in both cases, radio-iodine treatment was impossible, and symptomatic treatment and antithyroid drugs had to be used. Thus, it is concluded that topical treatment with cadexomer iodine can induce hyperthyroidism difficult to manage clinically as the treatment options are limited, which should be borne in mind when cadexomer iodine treatment is considered.

The Fy(x) phenotype is associated with a missense mutation in the Fy(b) allele predicting Arg89Cys in the Duffy glycoprotein

The molecular basis of the three major alleles (Fy(a)/Fy(b)/Fy) of the Duffy (FY) blood group system has recently been established but the Fy(x) phenotype associated with weak expression of the Fy(b) and other FY antigens is poorly understood. In the Fy(x) genes of five unrelated British and Swedish donors with the Fy(a+b+weak) phenotype we found two missense mutations predicting amino acid changes Arg89Cys and Ala100Thr in the FY glycoprotein. The same mutations were found in two Fy(a-b+weak) samples from individuals of Swedish and Algerian origin. Their red blood cells showed a marked decrease in Fy(b), Fy3 and Fy6 expression measured by routine serology and flow cytometry. The rare FY genotypes Fy(x)Fy(x) and Fy(x)Fy were confirmed by family studies and DNA sequencing. Screening by allele-specific primer PCR (ASP-PCR) for these mutations among 100 Caucasian and 100 Black random blood donors indicated allele frequencies of 2.5% and 0% respectively. Ala100Thr alone was present in 33% of the Caucasians (but none of the Blacks) with no weakening of FY expression. A novel allele at the FY locus associated with the Fy(x) phenotype was studied. Mistyping of this weak Fy(b) antigen in clinical transfusion medicine may lead to delayed haemolytic transfusion reactions in immunized patients. A potential role for genomic typing is proposed.

The effects of cadexomer iodine paste in the treatment of venous leg ulcers compared with hydrocolloid dressing and paraffin gauze dressing. Cadexomer Iodine Study Group

BACKGROUND

The aim was to examine cadexomer iodine paste in a comparative clinical trial.

METHODS

A 12-week, randomized, open, controlled, multicenter, multinational trial in patients with exudating, venous leg ulcers of cadexomer iodine paste (Iodosorb/Iodoflex), hydrocolloid dressing (Duoderm E, Granuflex E), or paraffin gauze dressing (Jelonet) was carried out. All patients used short-stretch compression bandages (Comprilan) throughout the study. The primary efficacy variable was a reduction in ulcer size (%), and the secondary end-point was the time taken to stop exudation, when the patient had completed the study according to the protocol. A total of 153 patients entered the study and were treated for 12 weeks or until cessation of exudation.

RESULTS

The mean reduction in ulcer size in all patients was 62% with cadexomer iodine vs. 41% and 24% for hydrocolloid and paraffin gauze (ns). Of those treated for 12 weeks (n = 51), ulcer area reduction was 66% for cadexomer iodine and 18% for hydrocolloid (p = 0.0127). For the whole material, the rate of healing (ulcer area reduction per week) was significantly higher for cadexomer iodine than for paraffin gauze (0.64 cm2/week vs. 0.19 cm2/week, p = 0.0353). The treatment costs were similar in all groups; however, when the costs were correlated with healing over a 12-week period, cadexomer iodine paste was found to be more cost effective than hydrocolloid dressing or paraffin gauze dressing.

CONCLUSIONS

This study shows that cadexomer iodine paste is an efficient, cost-effective and safe alternative to hydrocolloid dressing and paraffin gauze dressing for the treatment of venous leg ulcers.

Periodontal conditions following surgical and orthodontic treatment of palatally impacted maxillary canines--a follow-up study

This follow-up study reports on the periodontal status 1 to 18 years after the completion of orthodontic treatment of unilateral palatally impacted maxillary canines and their adjacent incisors and premolars. Registrations were performed on 42 patients, 19 to 59 years old (mean 35 years) at investigation. An orthodontic pin with eyelet had been placed after exploration of the canine and, in some cases, bone removal. A flap had been raised and resutured after bone removal in 11 cases. The results showed greater mesial probing depth of the canines on the treated side, on the adjacent lateral incisors distolingually, and on the first premolars mesiolingually. Marginal bone level was found to be lower on the distal aspect of the treated canines and adjacent laterals. In general, the results showed a good gingival and periodontal status with slight differences between treated and untreated sides.

A clinically applicable method for determining the three major alleles at the Duffy (FY) blood group locus using polymerase chain reaction with allele-specific primers

BACKGROUND

The clinically significant antigens of the Duffy (Fy [FY]) blood group system are expressed on the red cell form of the FY glycoprotein, a promiscuous chemokine receptor and also a receptor for malarial parasites. After the cloning of cDNA coding for FY glycoprotein, the molecular basis of the three major alleles (Fya/Fyb/Fy) has been established. Because of the mistyping of the silent Fy allele as Fyb, the error rate of current genotyping methods is high in black populations.

STUDY DESIGN AND METHODS

Two hundred blood donors (European whites and African Blacks) and some amniotic DNA samples were investigated by a new allele-specific primer polymerase chain reaction technique. Sense primers corresponding to normal and GATA-1-mutated FY gene promoter region sequences were combined with antisense primers discriminating the Fya/Fyb polymorphism.

RESULTS

Complete correlation between FY phenotypes and genotypes was obtained in all samples studied, although, in two whites and one black, serology showed weak Fyb expression while polymerase chain reaction indicated a Fyb allele. Gene frequencies were calculated.

CONCLUSION

This simple and rapid polymerase chain reaction method was shown to detect the three common alleles at the FY locus in two representative ethnic populations. Its future use as an independent technique in red cell FY investigations and for fetal genotyping in hemolytic disease of the newborn is predicted.

The macrophage migration inhibitory factor MIF is a phenylpyruvate tautomerase

A macrophage migration inhibitory factor (MIF), originally described as a product of activated lymphocytes, has been defined as a 12 kDa protein, expressed in a wide variety of tissues. Here MIF is identified as a phenylpyruvate tautomerase (EC 5.3.2.1) having p-hydroxyphenylpyruvate and phenylpyruvate as its natural substrates. The definition of MIF as an enzyme may yield insight into the mechanism of action of this proinflammatory and immunomodulating cytokine.

Interactive wound dressings. A practical guide to their use in older patients

The properties of an ideal wound dressing do not change with the introduction of new types of wound dressing, but the range of effects on wound healing increases. The number of dressings available is enormous, and the choice between them is often bewildering. Because there is still no ideal dressing for all wound types, it is necessary to get to know a few well, and to avoid switching to new therapies solely on the basis of anecdotal reports. The adoption of novel dressings should be based on scientific evidence. At present, dressings are still chosen on the basis of local traditions and personal empirical experience, together with evidence from the few double-blind, placebo-controlled trials that have been performed. In the management of ulcers, a particular wound management plan should not be changed if the ulcer being treated is decreasing in size and the patient is comfortable. The dressing should be chosen with care. The type of chronic ulcer and its appearance, the amount of exudate and the presence or absence of pain all assist in the selection of an appropriate wound dressing product. Quality-of-life aspects are important. In the elderly, good quality of life may not necessarily require complete ulcer healing, although this is naturally desirable. Dressing changes should be minimised and the ulcer should be kept moist and the surrounding skin dry. The high cost of interactive dressings is a potential disadvantage of their use. However, if the wound can be re-dressed at longer intervals and if healing occurs more quickly, their use may be cost effective and associated with less pain and a better quality of life.

Concomitant contact dermatitis due to textile dyes and to colour film developers can be explained by the formation of the same hapten

p-phenylenediamine derivatives are widely used in industry and in cosmetics, and several of them are well-known sensitizers. One group of allergenic p-phenylenediamine derivatives are used as colour film developers. Cross-reactivity between the colour film developers has been reported. In this paper, an occupational facial dermatitis due to colour film developers is described. The patient reacted to colour film developers (CD-1, CD-2, CD-3, and CD-4), but not to other p-phenylenediamine derivatives tested. He also showed allergic reactions to Disperse Blue 106 and Disperse Blue 124 and to Disperse Red 17, but not to Disperse Orange 3. The activation of the colour film developers by oxidation at physiological pH was analysed with chemical methods, and the mechanism responsible for the concomitant reactivities to the colour film developers and the disperse dyes at a molecular level is discussed.

Extraction of mercaptobenzothiazole compounds from rubber products

At evaluation of contact dermatitis caused by solid material, patch testing is usually performed with the material as such and with extracts of it. In this study, optimization of the extraction technique monitored by quantitative HPLC analysis of the extracted haptens is described for mercaptobenzothiazole derivatives. Several solvents with different properties are included. Acetone has traditionally been a solvent widely used for the extraction of organic haptens from solid products. However, acetone and other ketones are not inert solvents. The rubber accelerators 2-(4-morpholinyl mercapto) benzothiazole (MMBT) and N-cyclohexyl-2-benzothiazyl sulfenamide (CBS) react with acetone, yielding 2 new compounds, which were isolated and characterised by NMR and MS. For the extraction of solid rubber products, methyl tert-butyl ether (MTBE) was found to be a more suitable solvent which is unreactive to most common haptens.