Hosts as ecological traps for the vector of Lyme disease

Vectors of infectious diseases are generally thought to be regulated by abiotic conditions such as climate or the availability of specific hosts or habitats. In this study we tested whether blacklegged ticks, the vectors of Lyme disease, granulocytic anaplasmosis and babesiosis can be regulated by the species of vertebrate hosts on which they obligately feed. By subjecting field-caught hosts to parasitism by larval blacklegged ticks, we found that some host species (e.g. opossums, squirrels) that are abundantly parasitized in nature kill 83-96% of the ticks that attempt to attach and feed, while other species are more permissive of tick feeding. Given natural tick burdens we document on these hosts, we show that some hosts can kill thousands of ticks per hectare. These results indicate that the abundance of tick vectors can be regulated by the identity of the hosts upon which these vectors feed. By simulating the removal of hosts from intact communities using empirical models, we show that the loss of biodiversity may exacerbate disease risk by increasing both vector numbers and vector infection rates with a zoonotic pathogen.

Successful treatment of severe juvenile microscopic polyangiitis with rituximab

Microscopic polyangiitis (MPA) previously called hypersensitivity angiitis is a systemic necrotizing vasculitis affecting predominantly small vessels. MPA involves multiple organ systems including the lung, the kidneys, the joints, and the skin. MPA mostly affects adults in their fourth and fifth decade of life. MPA and Wegener;s granulomatosis are grouped together as ANCA-associated vasculitis. MPA is associated with high titre of myeloperoxidase antineutrophil cytoplasmic antibodies (MPO)-ANCA. We present a 14-year-old female patient presented with MPA. She was treated with steroids and cyclophosphamide. After the complication of severe lung involvement, rituximab was administered as immune-modulating treatment. The MPA came to remission. This is the first report of a pediatric patient with MPA treated with rituximab. Rituximab might be a potential therapeutic option for relapsing ANCA associated vasculitis in childhood.

Differences in the metabolism and pharmacokinetics of two structurally similar PPAR agonists in dogs: involvement of taurine conjugation

1. The metabolism and pharmacokinetics of two structurally similar PPAR agonists, MRL-I, (2R)-7-[3-[2-chloro-4-(4-fluorophenoxy)phenoxy]propoxy]-2-ethyl-3,4-dihydro-2H-benzopyran-2-carboxylic acid, and MRL-II, (2R)-7-[3-[2-chloro-4-(2,2,2,-trifluoroethoxy)phenoxy]propoxy]-3,4-dihydro-2-methyl-2H-benzopyran-2-carboxylic acid, in dogs were investigated. 2. MRL-I was absorbed rapidly in dogs and exhibited linear pharmacokinetics over the dose range examined, 1-25mgkg(-1). In contrast, the pharmacokinetics of MRL-II were non-linear following both intravenous and oral administration. 3. The acyl glucuronide (AG) conjugate was the only radioactive component detected in bile from dogs dosed with [14C]MRL-I, whereas bile from dogs dosed with [14C]MRL-II contained varying amounts of both the AG and taurine conjugates. The percentages of the acyl glucuronide and taurine conjugates of [14C]MRL-II in dog bile were dose dependent. A higher percentage of radioactivity was associated with the taurine conjugate (about 41%) following intravenous administration at 0.2mgkg(-1) than at 0.9mgkg(-1) (about 14%) or oral administration at 5 mgkg(-1) (about 6%). The decrease in the percentage of radioactivity associated with the taurine conjugate at 0.9 mgkg(-1) was accompanied by a concomitant increase in the amount of the acyl glucuronide. 4. MRL-I, but not MRL-II, was subject to significant enterohepatic recirculation in dogs. Continuous collection of bile resulted in an 11-fold decrease in the terminal half-life of MRL-I in plasma (1.5 versus 16.6 h), and a 2.4-fold increase in its plasma clearance (4.0 versus 1.7 ml min(-1) kg(-1)) after intravenous administration at 1 mg kg(-1). 5. Collectively, the data suggest that the presence and subsequent saturation of the taurine conjugation pathway might have contributed to the non-linear pharmacokinetics of MRL-II in the dog.

Colonoscopy is the preferred colorectal cancer screening method in a population-based program

BACKGROUND AND STUDY AIMS

Various screening methods for colorectal cancer (CRC) are promoted by professional societies; however, few data are available about the factors that determine patient participation in screening, which is crucial to the success of population-based programs. This study aimed (i) to identify factors that determine acceptance of screening and preference of screening method, and (ii) to evaluate procedure success, detection of colorectal neoplasia, and patient satisfaction with screening colonoscopy.

PATIENTS AND METHODS

Following a public awareness campaign, the population aged 50 - 80 years was offered CRC screening in the form of annual fecal occult blood tests, flexible sigmoidoscopy, a combination of both, or colonoscopy.

RESULTS

2731 asymptomatic persons (12.0 % of the target population) registered with and were eligible to take part in the screening program. Access to information and a positive attitude to screening were major determinants of participation. Colonoscopy was the method preferred by 74.8 % of participants. Advanced colorectal neoplasia was present in 8.5 %; its prevalence was higher in males and increased with age. Significant complications occurred in 0.5 % of those undergoing colonoscopy and were associated with polypectomy or sedation. Most patients were satisfied with colonoscopy and over 90 % would choose it again for CRC screening.

CONCLUSIONS

In this population-based study, only a small proportion of the target population underwent CRC screening despite an extensive information campaign. Colonoscopy was the preferred method and was safe. The determinants of participation in screening and preference of screening method, together with the distribution of colorectal neoplasia in different demographic categories, provide a rationale for improving screening procedures.

Biosynthesis and assembly of the largest and major intrinsic polypeptide of the small intestinal brush borders

The sucrase-isomaltase complex (SI) of the small intestinal brush border membrane accounts for approximately 9-10% of the intrinsic protein. The isomaltase subunit alone interacts with the membrane directly, via a highly hydrophobic segment at its N-terminal region. This segment has a helical conformation for more than 85% and crosses the membrane twice, the N-terminus being located at the outer, luminal side of the membrane. The sucrase subunit is attached to the membrane solely via its interactions with the isomaltase subunit. The sucrase-isomaltase complex is synthesized as a single, very long (Mr approximately 260 000) polypeptide chain (pro-SI, carrying the two sites of sucrase and isomaltase in an already enzymically active form), with the isomaltase portion corresponding to the N-terminal part of pro-SI. Pro-SI is processed into 'final' SI by pancreatic proteases. Recently the cell-free translation of pro-SI has been achieved in vitro. From a detailed knowledge of the anchoring of SI (and pro-SI) in the membrane it has been possible to suggest one particular mechanism as the most likely for the synthesis, insertion and assembly of pro-SI.

Is MAO-B activity in platelets associated with the occurrence of suicidality and behavioural personality traits in depressed patients?

OBJECTIVE

Low platelet monoaminoxidase B (MAO-B) activity has been associated with various forms of impulsive behaviour and suicidality. The present study investigated the relationship between MAO-B activity in platelets and aspects of suicidality in depressed patients and controls.

METHOD

In 87 patients with affective spectrum disorders (58% suffering from a major depressive episode - MDE) the potential association between platelet MAO-B activity and suicidality was examined. Fifty-nine of the patients had committed suicide attempt recently (SA -'suicide attempters'), 28 patients were acutely depressed without having shown suicidal thoughts or suicidal behaviour in the past (NA -'non-suicide attempters').

RESULTS

The SA and NA were comparable as to their diagnoses and general demographic and psychopathological parameters. MAO-B activity did not differ between SA and NA. No systematic correlations existed between MAO-B activity and any dimensions of suicidal behaviour or psychopathology. As a single finding only a weak positive association of higher MAO-B activity in SA with a fatal intention of the SA was observed.

CONCLUSION

Our findings do not support a consistent association of platelet MAO-B activity and suicidal behaviour in general, but specific facts of suicidality might be associated.

Comparison of female attractiveness and male response among populations of Choristoneura rosaceana (Harris) in western and eastern U.S. apple orchards

Female obliquebanded leafrollers, Choristoneura rosaceana (Harris), collected from Oregon, Michigan, and New York were deployed in delta traps in Michigan apple orchards to compare their relative attractiveness to Michigan males of the same species. Females originating from Oregon attracted more males than females originating from New York during both generations of leafroller flight in Michigan. Also, females from Oregon attracted more males in Michigan than did "native" Michigan females during the first generation of flight. Analysis of gland extracts from the three populations revealed significantly more of each pheromone component in females originating from Oregon (approximately nine-fold more pheromone per female overall) than those from Michigan. However, there were no significant differences in the relative amounts of each pheromone component between Oregon and Michigan females. A 100:4:5:2 blend of Z11-14:OAc, E11-14:OAc, Z11-14:OH, and Z11-14:Ald was optimal for catching males in Michigan with no added or detrimental effect of Z11-14:Ald, confirming previous studies. However, 100:1 ratios of Z11-14:OAc relative to either E11-14:OAc or Z11-14:OH (also containing 2% Z11-14:Ald) captured more males in Oregon apple orchards compared with 100:4 and 100:10 ratios of Z11-14:OAc relative to either E11-14:OAc or Z11-14:OH. Addition of increasing amounts of Z11-14:Ald relative to Z11-14:OAc (range, 0-8:100) into a blend also containing 4% E11-14:OAc and 5% Z11-14:OH increased male catch in Oregon but not in Michigan. Our results suggest that pheromone blend quantity rather than blend quality may explain greater attractiveness of western compared with eastern female C. rosaceana to males in Michigan. Also, an optimized generic blend for monitoring male C. rosaceana across North America should contain Z11-14:Ald as has been previously shown, but should not exceed 4:100 ratios of both E11-14:OAc and Z11-14:OH relative to Z11-14:OAc for optimized catch of males in the western United States.

[Kelley-Seegmiller syndrome]

BACKGROUND

Hypoxanthinguanin-phosphoribosyltransferase (HPRT) deficiency, an x-linked inherited disease can cause two presentations: A complete deficiency (Lesch-Nyhan syndrome) accompanies with grave renal and neurological symptoms. A second form is the partial enzyme deficiency (Kelley-Seegmiller syndrome).

PATIENT

We present a thirteen year old boy with relapsing hyperuricemia and hypercreatininemia. In the framework of postoperative renal insufficiency the diagnose of a Kelley-Seegmiller syndrome was elaborated.

RESULT

About 25% of patients with Kelley-Seegmiller syndrome present mild neurological symptoms but never with self-destructive behavior. Pathophysiological an increased de novo purinsynthesis is present. Therefore, it comes to an overproduction of urine acid. Urolithiasis is one clinical manifestation.

CONCLUSION

Relapsing urolithiasis and renal insufficiency has to be worked up. In the differential diagnosis a disorder of purine metabolism has to be discussed.

X-linked chronic granulomatous disease (CGD) caused by an intra-exonic splice mutation (CYBB exon 3, c.262G->A) is mimicking juvenile sarcoidosis

BACKGROUND

Chronic granulomatous disease (CGD) is caused by mutations in genes encoding nicotinamide dinucleotide phosphate (NADPH) oxidase subunits.

CASE REPORT

A boy was diagnosed as having juvenile sarcoidosis because he presented with cervical and pulmonary lymphadenopathy with epitheloid cells and granuloma formation and high angiotensin converting enzyme. Later, a liver abscess was diagnosed. CGD was established by a dihydrorhodamine 123 (DHR) assay and genetic analysis revealed an unusual intra-exonic splice mutation in the CYBB gene encoding gp91-phox. It did not change the amino acid sequence and allowed for residual NADPH oxidase activity explaining the late onset of the disease.

CONCLUSION

CGD is an important differential diagnosis of juvenile sarcoidosis.

The diagnostic value of anti-cyclic citrullinated peptide (CCP) antibodies in children with Juvenile Idiopathic Arthritis

BACKGROUND

Antibodies against cyclic citrullinated peptide (anti-CCP) are considered to be specific for rheumatoid arthritis (RA).

OBJECTIVE

To assess the clinical significance of anti-CCP antibodies in a cohort of patients with juvenile idiopathic arthritis (JIA) and if they can be used to identify patients with an unfavourable course of disease.

METHODS

68 serum samples were investigated. 45 patients were diagnosed with JIA (15 male and 30 female) aged 1.9-17.3 years (median 12.9 mean 11,0). 5 patients had polyarticular (RF negative), 2 polyarticular (RF positive), 25 oligoarticular JIA, 6 enthesitis related arthritis, 2 psoriatric arthritis, 3 patients had systemic disease and 2 unclassified arthritis. 23 samples were taken from patients with non-inflammatory cardiac diseases undergoing interventional cardiac therapy. Enzyme-linked immunosorbent assay (ELISA; Euroimmun, Lübeck, Germany) was used for the detection and quantification of anti-CCP antibodies in patients with JIA.

RESULTS

Overall, anti-CCP antibodies were found in 2.9% (2/68) of all samples and in 4.4 % (2/45) patients with JIA.

CONCLUSION

Anti-CCP antibodies are associated with RF positive polyarticular course of JIA. Anti-CCP antibodies are not relevant for other subgroups of JIA. Therefore anti-CCP Abs in patients with JIA should not be investigated routinely.