Mycoplasma hafezii sp. nov., isolated from the trachea of a peregrine falcon (Falco peregrinus).

Mycoplasma species are well known pathogens in avian medicine, especially in poultry. However, several Mycoplasma species have been regularly found in the respiratory tract of birds of prey which seem to be commensals in these bird species. In previous studies, an unknown Mycoplasma species which caused false positive results in a Mycoplasma meleagridis-specific PCR, was isolated from a tracheal swab of a clinically healthy, captive, adult peregrine falcon (Falco peregrinus). The isolate appeared in typical fried-egg-shaped colonies on SP4 agar plates and was dependent on sterol for growth. Acid was produced from glucose, but no arginine or urea was hydrolysed. The temperature range for growth was 28-44 °C, with an optimum at 37 °C. Strain M26T was serologically distinct from all species of the genus Mycoplasma with 16S rRNA gene sequence similarity ≥94 %. Biochemical, serological and molecular biological properties demonstrate that this organism represents a novel species of the genus Mycoplasma, for which the name Mycoplasma hafezii sp. nov. is proposed; the type strain is M26T (NCTC 13928, DSM 27652).

Comparative study of gastrointestinal tract size in three parent breeds for the production of dual-purpose organic chickens.

An alternative to culling male hatchlings of layers is breeding dual-purpose chickens. One breeding objective is the ability to digest low-quality feed. Certain measurements of the gastrointestinal tract may be useful indicators of this ability. The present study compared the gastrointestinal tract of adult hens of two layer-type breeds (White Rock (WR), New Hampshire (NH)) and the meat-type ÖTZ (Ökologische Tierzucht gGmbH) Bresse Gauloise (BR), used for the production of dual-purpose organic chickens. Flocks had the same housing and feeding conditions. At slaughter at 19 months, the body weight and gastrointestinal organs of 134 hens (51 WR, 55 NH and 28 BR) were measured. The muscle thickness of the proventriculus and ventriculus and the length and width of the duodenum, jejunoileum, caeca and colorectum were measured and variances between the groups were analysed using a one-factor covariance analysis. Significant differences between the breeds were found in total intestine length and the lengths and/or widths of single gastrointestinal segments. For example NH showed the highest mean total intestinal length and BR showed the lowest mean (NH: 186.73 cm, WR 185.86 cm, BR 157.91 cm; p = 0.001). To our knowledge, this is the first study comparing the gastrointestinal tract size of adult female layer- and meat-type chicken breeds kept under the same feeding and housing conditions. Given the possible relationship between intestinal length parameters and chicken performance, measurement of the gastrointestinal tract may be a simple, quick and inexpensive additional method to help select layer-, meat-type and dual-purpose chickens suitable for organic production when a selection process using genetic markers is not possible.

Chronic myelomonocytic leukemia and primary Sjögren's syndrome.

Although associations of Sjögren's syndrome (SS) with malignant affections are well known, an association with chronic myelomonocytic leukemia (CMML) is infrequent. Our report concerns an 80-year-old woman with chronic polyarthrosis, hospitalized for an anemic syndrome, who also complained of buccal dryness. Clinical examination showed simply parotid swelling and discrete splenomegaly. The diagnosis of SS appeared to be primary. The hemogram, myelogram and bone biopsy indicated CMML. During SS, the possibility of occurrence of a lymphoproliferative syndrome is well documented, and other malignant affections are much less likely to be found in the absence of immunosuppressive treatment. The particular case of SS and associated CMML detected at the same time suggests either the favorable role of monocytic proliferation on immunity or a stem clonal anomaly affecting monocytes and B lymphocytes.

Pressure- and heat-induced inactivation of butyrylcholinesterase: evidence for multiple intermediates and the remnant inactivation process.

The inactivation process of native (N) human butyrylcholinesterase (BuChE) by pressure and/or heat was found to be multi-step. It led to irreversible formation of an active intermediate (I) state and a denatured state. This series-inactivation process was described by expanding the Lumry-Eyring [Lumry, R. and Eyring, H. (1954) J. Phys. Chem. 58, 110-120] model. The intermediate state (I) was found to have a K(m) identical with that of the native state and a turnover rate (k(cat)) twofold higher than that of the native state with butyrylthiocholine as the substrate. The increased catalytic efficiency (k(cat)/K(m)) of I can be explained by a conformational change in the active-site gorge and/or restructuring of the water-molecule network in the active-site pocket, making the catalytic steps faster. However, a pressure/heat-induced covalent modification of native BuChE, affecting the catalytic machinery, cannot be ruled out. The inactivation process of BuChE induced by the combined action of pressure and heat was found to continue after interruption of pressure/temperature treatment. This secondary inactivation process was termed 'remnant inactivation'. We hypothesized that N and I were in equilibrium with populated metastable N' and I' states. The N' and I' states can either return to the active forms, N and I, or develop into inactive forms, N(')(in) and I(')(in). Both active N' and I' intermediate states displayed different rates of remnant inactivation depending on the pressure and temperature pretreatments and on the storage temperature. A first-order deactivation model describing the kinetics of the remnant inactivation of BuChE is proposed.

Capillary zone electrophoresis with optimized temperature control for studying thermal denaturation of proteins at various pH.

Capillary electrophoresis (CE) was used to analyze the thermal denaturation of bovine beta-lactoglobulin at different pH. This model protein exhibits complex pH- and temperature association/dissociation dependence balances in its quaternary structure. The study was possible after modification and improvement of a capillary electrophoresis apparatus. The improvement allowed both efficient control (temperature fluctuations <0.05 degrees C) and accurate measurement of the temperature (+/- 0.1 degrees C) within the capillary cartridge. CE allowed the thermodynamic parameters of beta-lactoglobulin thermal denaturation to be estimated. The transition temperature, Tm, was determined at acidic, neutral and alkaline pH. Van't Hoff analysis was performed through direct measurement of native and unfolded protein populations in the slow-time regime. This allowed estimation of thermodynamic parameters (deltaH, deltaS, deltaCp). Finally, the stability curve, i.e., the temperature dependence of the free energy change (deltaG) of protein unfolding was drawn. The accuracy of the parameters values compares with parameters obtained by calorimetric measurements. The available parameters and the requirement of minute amount of protein sample are of potential interest in the field of protein engineering and biological pharmaceuticals. Accordingly, CE can be proposed as a convenient tool to study protein stability and denaturation processes.