Contribution of regulatory T cells to alleviation of experimental allergic asthma after specific immunotherapy

BACKGROUND

Allergen-specific immunotherapy (SIT) has been used since 1911, yet its mechanism of action remains to be elucidated. There is evidence indicating that CD4(+)FOXP3(+) regulatory T cells (Treg cells) are induced during SIT in allergic patients. However, the contribution of these cells to SIT has not been evaluated in vivo.

OBJECTIVE

To evaluate the in vivo contribution of (i) CD4(+) CD25(+) T cells during SIT and of (ii) SIT-generated inducible FOXP3(+) Treg cells during allergen exposure to SIT-mediated suppression of asthmatic manifestations.

METHODS

We used a mouse model of SIT based on the classical OVA-driven experimental asthma. Treg cells were quantified by flow cytometry 24 and 96 h post SIT treatment. We depleted CD4(+) CD25(+) T cells prior to SIT, and CD4(+)FOXP3(+) T cells prior to allergen challenges to study their contribution to the suppression of allergic manifestations by SIT treatment.

RESULTS

Our data show that depletion of CD4(+)CD25(+) T cells at the time of SIT treatment reverses the suppression of airway hyperresponsiveness (AHR), but not of airway eosinophilia and specific IgE levels in serum. Interestingly, the number of CD4(+)CD25(+)FOXP3(+) T cells is transiently increased after SIT in the spleen and blood, suggesting the generation of inducible and presumably allergen-specific Treg cells during treatment. Depletion of CD4(+)FOXP3(+) Treg cells after SIT treatment partially reverses the SIT-induced suppression of airway eosinophilia, but not of AHR and serum levels of specific IgE.

CONCLUSION AND CLINICAL RELEVANCE

We conclude that SIT-mediated tolerance induction towards AHR requires CD4(+)CD25(+) T cells at the time of allergen injections. In addition, SIT generates CD4(+)CD25(+)FOXP3(+) T cells that contribute to the suppression of airway eosinophilia upon allergen challenges. Therefore, enhancing Treg cell number or their activity during and after SIT could be of clinical relevance to improve the therapeutic effects of SIT.

CD137 deficiency does not affect development of airway inflammation or respiratory tolerance induction in murine models

The co-stimulatory molecule CD137 (4-1BB) plays a crucial role in the development and persistence of asthma, characterized by eosinophilic airway inflammation, mucus hypersecretion, airway hyperreactivity, increased T helper type 2 (Th2) cytokine production and serum immunoglobulin (Ig)E levels. We have shown previously that application of an agonistic CD137 monoclonal antibody (mAb) prevented and even reversed an already established asthma phenotype. In the current study we investigated whether deficiency of the CD137/CD137L pathway affects the development of allergic airway inflammation or the opposite immune reaction of respiratory tolerance. CD137⁻/⁻ and wild-type (WT) mice were sensitized and challenged with the model allergen ovalbumin (OVA) and analysed for the presence of allergic disease parameters (allergy protocol). Some animals were tolerized by mucosal application of OVA prior to transferring the animals to the allergy protocol to analyse the effect of CD137 loss on tolerance induction (tolerance protocol). Eosinophilic airway inflammation, mucus hypersecretion, Th2 cytokine production and elevated allergen-specific serum IgE levels were increased equally in CD137⁻/⁻ and WT mice. Induction of tolerance resulted in comparable protection from the development of an allergic phenotype in both mouse strains. In addition, no significant differences could be identified in CD4⁺, CD8⁺ and forkhead box protein 3 (FoxP3⁺) regulatory T cells, supporting the conclusion that CD137⁻/⁻ mice show equal Th2-mediated immune responses compared to WT mice. Taken together, CD137⁻/⁻ mice and WT mice develop the same phenotype in a murine model of Th2-mediated allergic airway inflammation and respiratory tolerance.

Impact of enzymatic tissue disintegration on the level of surface molecule expression and immune cell function

Immunological characterization of immune cells that reside in specific anatomic compartments often requires their isolation from the respective tissue on the basis of enzymatic tissue disintegration. Applying enzymatic digestion of primary splenocytes, we evaluated the impact of collagenase and dispase, two enzymes that are commonly used for the liberation of immune cells from tissues, on the detectability of 48 immunologically relevant surface molecules that are frequently used for flow cytometric identification, isolation, and characterization of immune cell subsets. Whereas collagenase treatment had only minor effects on surface expression of most molecules tested, dispase treatment considerably affected antibody-mediated detectability of the majority of surface markers in subsequent FACS analyses. This effect was long lasting and, in case of high-dose dispase treatment, evident for the majority of surface molecules even after 24 h of in vitro culture. Of note, high-dose dispase treatment not only affected surface expression of certain molecules but also impaired antigen-specific proliferation of CD4(+) and CD8(+) T cells. Together, our data indicate that enzymatic tissue disintegration can have profound effects on the expression of a variety of cell-surface molecules with direct consequences for phenotypic analysis, FACS- and MACS-based target cell isolation, and immune cell function in cell culture experiments.

Liraglutide: short-lived effect on gastric emptying -- long lasting effects on body weight

AIM

Previous studies with the novel once daily glucagon-like peptide-1 (GLP-1) analogue liraglutide and the GLP-1 receptor agonist exenatide have revealed profound insulinotrophic and antidiabetic effects, but also potent effects on gastric emptying (GE) and long-term and lasting reductions in body weight. In this study, we examined the acute and chronic effects of two different GLP-1 analogues with different pharmacokinetic profiles on GE, food intake and body weight.

METHODS

On the basis of a series of dose-finding studies, the doses of exenatide and liraglutide with similar acute anorectic effects were identified. GE was assessed using a standard acetaminophen release assay. After the acute test, rats were dosed bi-daily for 14 days in which period food intake and body weight was monitored. On day 14, the GE rate was reassessed.

RESULTS

While both compounds exerted robust acute reductions in GE, the effect was markedly diminished following 14 days of dosing with liraglutide. In contrast, exenatide-treated rats still displayed a profound reduction in GE at the 14-day time-point. Both compounds exerted similar effects on body weight.

CONCLUSION

The data suggest that the 'gastric inhibitory' GLP-1 receptors in rats are subject to desensitization/tachyphylaxis but that this effect is dependent on full 24-h exposure as obtained by liraglutide. The body weight-lowering effects of GLP-1 receptor stimulation are not subject to desensitization. These data indicate that regulation of appetite signals in the brain, and not GE, is the main mechanism for liraglutide-induced weight loss.

Cardiomyopathy in α-Kinase 3 (ALPK3)–Deficient Mice

Cardiomyopathy developed in mice deficient for α-kinase 3 (ALPK3), a nuclear kinase previously implicated in the differentiation of cardiomyocytes. Alpk3–/– mice were produced according to normal Mendelian ratios and appeared normal except for a nonprogressive cardiomyopathy that had features of both hypertrophic and dilated forms of cardiomyopathy. Cardiac hypertrophy in Alpk3–/– mice was characterized by increased thickness of both left and right ventricular (LV and RV) walls and by markedly increased heart weight and increased heart weight/body weight and heart weight/tibia length ratios. Magnetic resonance imaging studies confirmed the increased thickness in both septal and LV free walls at end-diastole, although there was no significant change in LV wall thickness at end-systole. Myocardial hypertrophy was the predominant feature in Alpk3–/– mice, but several changes more typically associated with dilated cardiomyopathy included a marked increase in end-diastolic and end-systolic LV volume, as well as reduced cardiac output, stroke volume, and ejection fractions, suggesting LV chamber dilation. Magnetic resonance imaging showed a 50% reduction in both septal and free wall LV contractility in Alpk3–/– mice. Interstitial fibrosis and inflammation were notably absent in Alpk3–/– mice; however, light and electron microscopy revealed altered cardiomyocyte architecture, characterized by reduced numbers of abnormal intercalated discs being associated with mild disarray of myofibrils. These lesions could account for the impaired contractility of the myofibrillar apparatus and contribute to the pathogenesis of cardiomyopathy in Alpk3–/– mice.

Pathology of congenital generalized lipodystrophy in Agpat2-/- mice

Congenital generalized lipodystrophy (CGL) comprises a heterogeneous group of rare diseases associated with partial or total loss of adipose tissue. Of these, autosomal recessive Berardinelli-Seip congenital lipodystrophy (BSCL) is characterized by the absence of metabolically active subcutaneous and visceral adipose tissues. Metabolic abnormalities associated with lipodystrophy include insulin resistance, hypertriglyceridemia, hepatic steatosis, and diabetes. One form of BSCL has been linked to genetic mutations affecting the lipid biosynthetic enzyme 1-acyl-sn-glycerol 3-phosphate O-acyltransferase 2 (AGPAT2), which is highly expressed in adipose tissue. Precisely how AGPAT2 deficiency causes lipodystrophy remains unresolved, but possible mechanisms include impaired lipogenesis (triglyceride synthesis and storage), blocked adipogenesis (differentiation of preadipocytes to adipocytes), or apoptosis/necrosis of adipocytes. Agpat2(-/-) mice share important pathophysiologic features of CGL previously reported in humans. However, the small white adipose tissue (WAT) depots consisting largely of amoeboid adipocytes with microvesiculated basophilic cytoplasm showed that adipogenesis with deficient lipogenesis was present in all usual locations. Although well-defined lobules of brown adipose tissue (BAT) were present, massive necrosis resulted in early ablation of BAT. Although necrotic or apoptotic adipocytes were not detected in WAT of 10-day-old Agpat2(-/-), the absence of adipocytes in aged mice indicates that these cells must undergo necrosis/apoptosis at some point. Another significant finding in aged lipodystrophic mice was massive pancreatic islet hypertrophy in the face of chronic hyperglycemia, which suggests that glucotoxicity is insufficient by itself to cause β-cell loss and that adipocyte-derived factors help regulate total β-cell mass.

Histopathological and neurological features of Atg4b knockout mice

This investigation found that genetic inactivation of mouse Atg4b, 1 of the 4 mammalian homologs of the autophagy-related gene Atg4, resulted in amorphous globular bodies in the neuropil of the deep cerebellar nuclei and adjacent vestibular nuclei but nowhere else in the brain or other tissues. The spheroid-like bodies in the deep cerebellar and vestibular nuclei showed heterogeneous composition, reactivity with anti-ubiquitin antibody, and staining characteristics of proteinaceous material. Atg4b-deficient (Atg4b (-/-)) mice also showed a mild but measurable impairment of motor performance on the Rotarod. Atg4b (-/-) mice produced by breeding heterozygous parents were produced at a slightly lower than expected ratio to heterozygous and wild-type siblings but showed no other clear abnormalities in a battery of screening tests. These findings appear to be different than those reported for inactivation of other Atg4 homologs, suggesting that these homologs have tissue-specific functions beyond redundancy.

Acquisition of Key-Pecking via Autoshaping as a Function of Prior Experience: "Learned Laziness"?

A group of pigeons that had previously received noncontingent food delivery acquired the key-peck response (in autoshape training) more slowly than did a naive control group; key-peck acquisition was most rapid for a group given operant treadle-press training in the initial phase.

Tubulin tyrosine ligase-like 1 deficiency results in chronic rhinosinusitis and abnormal development of spermatid flagella in mice

Tubulin tyrosine ligase-like 1 (TTLL1) protein is a member of the tubulin tyrosine ligase superfamily of proteins that are involved in the posttranslational polyglutamylation of tubulin in axonemal microtubules within cilia and flagella. To investigate the physiological role of TTLL1, the authors generated mice with a gene trap mutation in the Ttll1 gene that provide confirmation in a mammalian model that polyglutamylation plays an important role in some ciliary and flagellar functions. For the first time, mice homozygous for the Ttll1 mutation exhibited accumulations of exudates in the nasal passages and sinuses, rhinosinusitis, otitis media, and male infertility. In homozygous mutant male mice, abnormal sperm morphology and function were characterized by shortened or absent flagella and immotility. Although homozygous mutant males were infertile, the females were fertile. These findings are consistent with a diagnosis of primary ciliary dyskinesia (PCD) resulting from ciliary dysfunction. They indicate that Ttll1 is essential for normal motility of respiratory cilia and the biogenesis and function of sperm flagella but that the defect does not result in the hydrocephalus or laterality defects often seen in other forms of PCD. The absence of early-onset lethal hydrocephalus in Ttll1-mutant mice may enable studies to evaluate the long-term effects of PCD in the respiratory system of mice. Although no mutations in the orthologous gene have been linked with PCD in humans, investigating the role of TTLL1 and polyglutamylation of tubulin in cilia and flagella should advance an understanding of the biogenesis and function of these organelles in mammals and have potential diagnostic and therapeutic applications.

ECG recording in emergency home visits

During the first half of 1974, 756 emergency home calls have been made by 6 doctors in the City of Oslo. A portable ECG instrument was available at all visits. The visits were unselected as regards complaints. ECG was recorded in 7% of all patients and in 19% of all patients over 60 years of age. The main indication for recording an ECG was chest pain (nearly 2/3 of all recordings). In only a small number of cases did the recording give a definite result as regards diagnosis of management of the case. However, a slight additional benefit was obtained with a majority of the ECG recordings, including what we defined as a phychotherapeutic benefit. The results of this study indicate that the value of a portable electrocardiograph is very limited for emergency home calls in a city.

Ectonucleoside triphosphate diphosphohydrolase type 5 (Entpd5)-deficient mice develop progressive hepatopathy, hepatocellular tumors, and spermatogenic arrest

Ectonucleoside triphosphate diphosphohydrolase type 5 (ENTPD5, also CD39L4) is a soluble enzyme that hydrolyzes purine nucleoside diphosphates. Genetic inactivation of ENTPD5 in mice (Entpd5(-/-)) resulted in 2 major histopathologic lesions: hepatopathy and aspermia. The hepatopathy was progressive and characterized by centrilobular hepatocyte hypertrophy, oval cell proliferation, bile staining of Kupffer cells, and hepatocyte degeneration with increasing incidence and severity of degenerative lesions, development of multiple foci of cellular alteration, and hepatocellular neoplasia with age. Greatly increased proliferation of hepatocytes in young adult as well as aged Entpd5(-/-) mice was demonstrated by Ki67 immunohistochemistry and 5'-bromo-3'-deoxyuridine incorporation. Of 15 Entpd5(-/-) mice between 44 and 69 weeks of age, all showed foci of cellular alteration in the liver, and at least 6 of 15 developed hepatocellular carcinoma (HCC), hepatocellular adenoma, or both. Significantly, none of these lesions were observed in 13 wild-type Entpd5(+/+) littermates. These findings, combined with the historically low incidence (about 5%) of HCC in mice up to 2 years of age with the same genetic background, strongly suggest that loss of Entpd5 promotes hepatocellular neoplasia in mice. In humans, ENTPD5 has been found to be identical to the PCPH proto-oncogene, and dysregulation of this gene has been demonstrated in some human cancers. This mouse model could contribute to the understanding of the influence of ENTPD5/PCPH on cellular proliferation and neoplasia.

Maternal tolerance achieved during pregnancy is transferred to the offspring via breast milk and persistently protects the offspring from allergic asthma

BACKGROUND

Maternal, more than paternal, asthma is a risk factor for the development of asthma in children. Recently, epidemiologic studies have shown that environmental exposures during pregnancy might influence the development of childhood asthma and allergies.

OBJECTIVE

The aim of the present study was to investigate whether the induction of tolerance against a specific antigen during pregnancy prevents in the offspring the development of allergic asthma in response to this antigen.

METHODS

Balb/c mice were orally tolerized with ovalbumin (OVA) during pregnancy. The offspring of tolerized and naïve mothers were immunized with OVA at 6 weeks and 4 months of age and analysed in our murine asthma model.

RESULTS

While the offspring of naïve mice developed increased AHR, eosinophilic airway inflammation, T-helper type 2 cytokine production and high serum IgE levels in response to OVA sensitization, the offspring of tolerized mice were almost completely protected from asthma, even when immunized as late as 4 months after birth. Breastfeeding was crucial for protection because tolerance was only observed when the offspring were nursed by their own mothers and not when nursed by naïve wet-nurses. Allergen-specific IgG(1) antibodies were exclusively increased in the breast milk of tolerant mothers and serum of protected pups, indirectly supporting its important role in tolerance transfer from the mother to the offspring. Sensitization of the F1 generation from OVA-tolerized mothers with a heterologous allergen enhanced the immune response to this antigen.

CONCLUSION

Our results demonstrate that mucosal allergen contact during pregnancy modifies the asthma and allergy risk of the offspring mediated via breast milk. This observation may suggest that the time window for primary prevention strategies starts even before early childhood during pregnancy.

First confirmed cases of Clostridium difficile PCR ribotype 027 in Norway

Since 2003, the emergence and distribution of a hypervirulent strain of Clostridium difficile PCR ribotype 027 has been described in North America, Japan and several European countries [1-6]. In December 2007, C. difficile PCR ribotype 027 was found in two cases of C. difficile-associated disease treated in a hospital in Oslo, Norway.

Cellulitis with compartment syndrome as a complication of varicella zoster infection

BACKGROUND

Varicella zoster infection (chickenpox) is a common and usually benign self limiting disease of childhood in non-vaccinated populations. Although varicella usually goes along with mild to moderate illness in immunocompetent patients, serious complications can arise. Varicella is highly infectious, with attack rates in susceptible individuals ranging from 61% to 100%.

PATIENT

This case describes a rare but life threatening complication of varicella zoster infection in a child.

CONCLUSIONS

High morbidity in non-vaccinated populations that led to rare cases of severe complications became a significant health burden all over the world. This aspect must be considered in the discussion about the importance and benefit of a population wide varicella vaccination programme as it was added to the childhood immunization schedule in Germany in 2004. The case described here might have been avoided by vaccination.

In vitro activity of fluoroquinolones against clinical isolates of Nocardia identified by partial 16S rRNA sequencing

Fluoroquinolones have several properties that make them potentially attractive candidates for the treatment of Nocardia infections, but information regarding their in vitro activity is limited. Minimum inhibitory concentrations (MIC) of five fluoroquinolones and other antimicrobials were determined by the reference broth dilution and E-test methods for 33 consecutive clinical isolates of Nocardia speciated by 16S rRNA gene sequences. The isolates included: Nocardia cyriacigeorgica (n = 6), N. nova (n = 8), N. farcinica (n = 8), N. brasiliensis (n = 3), N. asteroides (n = 4), and N. veterana (n = 4). MIC50/MIC90 results for ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin by broth dilution were 32/32, 2/4, 1/4, 32/32, and 2/2 microg/ml, respectively. The MICs by broth dilution and E-test were within a two-fold doubling dilution for 94%, 97%, 97%, 100%, and 100% of isolates for ciprofloxacin, gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin, respectively. For ciprofloxacin, the E-test results showed either complete categorical agreement or minor error compared to the reference broth dilution method for 97% (32/33) of the isolates. For other fluoroquinolones, using Streptococcus pneumoniae breakpoints, 94% (124/132) of MIC results by E-test showed either complete agreement or minor error compared to the reference broth dilution method. Fluoroquinolones show variable in vitro activity against clinical isolates of Nocardia spp., and MICs determined by the E-test show reasonable agreement with those determined by the reference broth dilution method.

CD137 ligand prevents the development of T-helper type 2 cell-mediated allergic asthma by interferon-gamma-producing CD8+ T cells

BACKGROUND

Allergic asthma is a T-helper type 2 (Th2) cell-mediated chronic disease that is characterized by airway hyperreactivity (AHR) and chronic eosinophilic airway inflammation. Several studies suggest co-stimulatory molecules like CD137 as potential targets for therapeutic interventions in allergic airway disease. Recently, we could show in a murine asthma model that administration of an agonistic antibody against the receptor of the co-stimulatory molecule CD137 prevented and even reversed an already-established asthma phenotype.

OBJECTIVE

The purpose of this study was to analyse the effect of stimulation of the CD137 ligand by a monoclonal antibody (CD137L mAb).

METHODS

To induce an asthma-like phenotype, BALB/c mice were sensitized to ovalbumin (OVA), followed by an intrapulmonary allergen challenge. Anti-CD137L or control mAb were applied 1 day before OVA immunization or after the asthma phenotype was already established.

RESULTS

Stimulation of the CD137L instead of the receptor by CD137L mAb prevents the development of an asthma-like phenotype but does not reverse established disease. While the receptor-mediated effect is partly mediated by anergy of CD4(+) T cells and partly by induction of IFN-gamma-producing CD8(+) T cells, the effect of the CD137L mAb is completely dependent on IFN-gamma-producing CD8(+) T cells: blockade of IFN-gamma and depletion of CD8(+) T cells fully abrogated the observed protective effect. In vitro experiments showed that the anti-CD137L mAb ligates directly to CD8(+) T cells and induces the generation of IFN-gamma by this cell population.

CONCLUSION

Our results demonstrate that anti-CD137L mAb prevents disease development via IFN-gamma-producing CD8(+) T cells but is inferior to stimulation of the receptor that reverses established disease by a mechanism including CD4(+) T cell anergy.

Antiproton confinement in a Penning-Ioffe trap for antihydrogen

Antiprotons (p[over]) remain confined in a Penning trap, in sufficient numbers to form antihydrogen (H[over ) atoms via charge exchange, when the radial field of a quadrupole Ioffe trap is added. This first demonstration with p[over] suggests that quadrupole Ioffe traps can be superimposed upon p[over] and e(+) traps to attempt the capture of H[over] atoms as they form, contrary to conclusions of previous analyses.

Ostomy bag management: comparative study of a new one-piece closed bag

The aim of this study was to compare the performance of a new one-piece closed ostomy bag, SenSura, to an already established bag with a focus on minimizing problems related to use of stoma bags for individuals with a colostomy. There were 68 Danish participants with a colostomy who tested each bag for 1 week in a randomized, open, comparative, crossover study. The SenSura bag was perceived more secure than the reference bag (p=0.0006). Crucial performance and safety parameters were rated significantly better for SenSura than for the reference bag. The high preference for SenSura (85%) reflected these results (p<0.0001). Individuals with a colostomy can expect a higher sense of security with the SenSura bag than with the reference bag. This may relate to good adhesion, tack, flexibility and effective filter performance. Future studies should examine the long-term effects of SenSura on peristomal skin conditions. To our knowledge, this is the first published comparative study of one-piece closed ostomy bags.

Rapid quantification of the toxic alga Prymnesium parvum in natural samples by use of a specific monoclonal antibody and solid-phase cytometry

The increasing incidence of harmful algal blooms around the world and their associated health and economic effects require the development of methods to rapidly and accurately detect and enumerate the target species. Here we describe use of a solid-phase cytometer to detect and enumerate the toxic alga Prymnesium parvum in natural samples, using a specific monoclonal antibody and indirect immunofluorescence. The immunoglobulin G antibody 16E4 exhibited narrow specificity in that it recognized several P. parvum strains and a Prymnesium nemamethecum strain but it did not cross-react with P. parvum strains from Scandinavia or any other algal strains, including species of the closely related genus Chrysochromulina. Prymnesium sp. cells labeled with 16E4 were readily detected by the solid-phase cytometer because of the large fluorescence signal and the signal/noise ratio. Immunofluorescence detection and enumeration of cultured P. parvum cells preserved with different fixatives showed that the highest cell counts were obtained when cells were fixed with either glutaraldehyde or formaldehyde plus the cell protectant Pluronic F-68, whereas the use of formaldehyde alone resulted in significantly lower counts. Immunofluorescence labeling and analysis with the solid-phase cytometer of fixed natural samples from a bloom of P. parvum occurring in Lake Colorado in Texas gave cell counts that were close to those obtained by the traditional method of counting using light microscopy. These results show that a solid-phase cytometer can be used to rapidly enumerate natural P. parvum cells and that it could be used to detect other toxic algae, with an appropriate antibody or DNA probe.

Vaccinations with T-helper type 1 directing adjuvants have different suppressive effects on the development of allergen-induced T-helper type 2 responses

BACKGROUND

Allergen-induced T-helper type 2 (Th2) responses can be inhibited with Th1 directing vaccines. However, studies comparing the efficacy of the different adjuvants have not been performed in detail.

OBJECTIVE

For this reason we compare the effects of live Bacillus-Calmette-Guerin(BCG), heat-killed (hk)-BCG, CpG-ODN (oligodeoxynucleotide) or PPD on the development of allergen-induced Th2 responses in mice.

METHODS

Ovalbumin (OVA)-specific allergic responses were induced in C57BL/6 mice by two intraperitoneally (i.p.) applications of OVA/alum followed by the intranasal challenge with OVA. The different Th1-inducing adjuvants were applied to the mice together with OVA/alum i.p. during the OVA-sensitization period and, subsequently, different parameters of allergic immune responses were evaluated.

RESULTS

All the adjuvants were effective in inhibiting the development of allergen-induced airway eosinophilia, mucous production and, with the exception of PPD, also airway hyper-reactivity, when they were applied together with OVA/alum. However, allergen-specific IgG1 and IgE serum levels were only reduced in live BCG- and PPD-treated mice. Suppression of airway eosinophilia was not observed in IFN-gamma- or IL-12-deficient mice (hk-BCG, CpG-ODN and PPD). Interestingly, live BCG was still able to suppress allergen-induced Th2 responses in the absence of either IFN-gamma or IL-12. When mice vaccinated with the different adjuvants together with OVA/alum were subjected to a second period of OVA/alum immunization, only live and hk-BCG were able to efficiently suppress the development of airway inflammation. This effect could be adoptively transferred by splenic CD4(+) T cells.

CONCLUSIONS

Taken together our data suggest that live BCG>hk-BCG>CpG-ODN >PPD are effective in suppressing allergen-induced Th2 responses. The degree of suppression and the component of the Th2 response affected (airway inflammation vs. the production of allergen-specific IgE and IgG1) were dependent upon the adjuvant used and how it was applied. Our results contribute to the design of novel vaccines protecting humans from developing allergic disorders.

Management of complications after hypospadias repair

OBJECTIVES

To review our experience with hypospadias complications (seen after 10%-15% of repairs) and to identify factors influencing outcome.

METHODS

We reviewed the available medical records of 113 patients who underwent repeat operation for hypospadias complications. Of the 113 patients, 40% had undergone the initial repair at our institution (internal referral); 60% had undergone the initial repair elsewhere before referral (external referral). The variables potentially affecting outcome were reviewed, including the severity of the defect, concomitant disease, age at the initial operation and revisions, type of complications and treatment, and the number of revisions. Outcomes were compared on the basis of specialty and experience.

RESULTS

Isolated hypospadias was present in 81% and other genitourinary abnormalities in 10%. External referral patients were older at the first revision (7.3 versus 4.2 years, P = 0.027). Complications included fistula (73%), stricture (12%), breakdown of repair (10%), and diverticulum formation (11%). Successful revision was independent of the initial defect. The first, second, and third revision was successful in 77%, 64%, and 67% of patients, respectively. The cumulative success rate was 77%, 92%, and 97% after each respective repair attempt. The success of the repair was independent of the patient's age at the initial operation/revision and of the interval from the initial repair to reoperation. Internal referral and external referral patients had similar results. Specific experience with the repair of hypospadias complications correlated with a successful outcome (P <0.001).

CONCLUSIONS

Complications after hypospadias repairs are common, with fistula accounting for approximately 75%. The outcome in our series was independent of hypospadias severity, patient age at repair, number of revisions, stent use, and referral status. Repairs performed by an experienced pediatric urologist were associated with improved outcomes (P <0.001).

Extreme climate of the global troposphere and stratosphere in 1940–42 related to El Niño

Although the El Niño/Southern Oscillation phenomenon is the most prominent mode of climate variability and affects weather and climate in large parts of the world, its effects on Europe and the high-latitude stratosphere are controversial. Using historical observations and reconstruction techniques, we analyse the anomalous state of the troposphere and stratosphere in the Northern Hemisphere from 1940 to 1942 that occurred during a strong and long-lasting El Niño event. Exceptionally low surface temperatures in Europe and the north Pacific Ocean coincided with high temperatures in Alaska. In the lower stratosphere, our reconstructions show high temperatures over northern Eurasia and the north Pacific Ocean, and a weak polar vortex. In addition, there is observational evidence for frequent stratospheric warmings and high column ozone at Arctic and mid-latitude sites. We compare our historical data for the period 1940-42 with more recent data and a 650-year climate model simulation. We conclude that the observed anomalies constitute a recurring extreme state of the global troposphere-stratosphere system in northern winter that is related to strong El Niño events.

Evaluation of the mercury exposure of dental amalgam patients by the Mercury Triple Test

AIMS

To establish and analyse reference data for the mercury burden of patients with and without amalgam fillings.

METHODS

Atomic absorption spectroscopy was used to quantify Hg concentrations in the scalp hair and urine (before and after application of dimercaptopropane sulphonate), and Hg release from dental amalgams (using a newly developed, amalgam specific chew test), in 2223 subjects.

RESULTS

50th centiles were 1.3 microg Hg/g creatinine in basal urine, 32 microg Hg/g creatinine after DMPS application, 454 ng Hg/g in hair, and 27 microg Hg per g of chewing gum, which corresponds to about 1 micro g Hg released per minute of chewing. Total Hg intake (from ambient air, drinking water, food, and amalgams) of most patients is well below the provisioned tolerable weekly intake (PTWI) defined by the WHO, unless extremely Hg rich food is consumed on a regular basis. However, for patients exceeding the 75th centile in chew tests, total Hg intake exceeds the PTWI by about 50%, even at the low limit of intake from food. In the absence of occupational exposure, significant Hg release from dental amalgams is a necessary but insufficient condition to obtain a high long term body burden. After removal of dental amalgams, chew tests no longer exhibit oral Hg exposure, while basal urine Hg content and DMPS induced excretion display a exponential decrease (half life about 2 months in both cases).

CONCLUSIONS

A standardised procedure for evaluation of the magnitude and origin of the Hg burden of individuals has been developed, which, by comparison with the database presented here for the first time, can serve as a diagnostic tool.

Effects of spaceflight on myosin heavy-chain content, fibre morphology and succinate dehydrogenase activity in rat diaphragm

The present study examined the effect of 14 days of exposure to microgravity during the Spacelab Life Sciences-2 (SLS-2) space shuttle mission on the myosin heavy-chain (MHC) content, fibre size and type distributions and metabolic properties of rat diaphragm. Five adult male Sprague-Dawley rats were exposed to 14 days of microgravity (SF, spaceflight) and compared to five ground-based controls (C). Immunohistochemical analyses using isoform-specific anti-MHC monoclonal antibodies revealed that 14 days of SF did not alter the proportions of type-I, -IIA, -IID/X or -IIB fibres within the crural, sternal or lateral costal regions of the diaphragm; the electrophoretically quantified MHC-isoform contents also remained unchanged. In contrast, the medial gastrocnemius (MG) and tibialis anterior (TA) muscles displayed slow-to-fast fibre type transitions: within the MG the proportion of type-IID/X fibres was reduced by 59% ( P<0.04) and corresponded to a 51% increase ( P<0.03) in type-IIB fibres. Within the TA, the sum of type-IID/X+IIB fibres was elevated by 24% ( P<0.02) at the expense of the slower type-IIA fibres, which decreased by 33% ( P<0.04). Electrophoretic analyses yielded qualitatively similar patterns of transformation. SF did not induce atrophic changes within the diaphragm, MG or TA. Succinate dehydrogenase activity remained unchanged in the crural diaphragm ( P>0.96) but was 34% lower ( P<0.0001) in the TA. We conclude that 14 days of SF did not alter structural or metabolic factors that are known to underlie functional properties of the diaphragm. The findings of the present study show that 14 days of SF does not induce deleterious adaptive changes in the rat diaphragm that occur in hindlimb muscles.