Malignant Peripheral Nerve Sheath Tumour in the Urinary Bladder of a Dog.

A 15-year-old neutered male miniature pinscher was presented with a pedunculated mass (4 × 1 cm) in its urinary bladder. Exploratory cystotomy revealed that the mass was located at the trigone of the bladder and projected into the lumen. The cut surface of the mass was homogeneous grey to tan in colour with focal brown pigmentation. Microscopically, the mass was predominantly composed of neoplastic spindle cells characterized by moderate cellular pleomorphism, invasion into the muscular layer of the bladder wall and few mitotic figures. The neoplastic spindle cells formed interwoven bundles intersecting at various angles. Immunohistochemically, these cells were negative for cytokeratin 7 and α-smooth muscle actin, but strongly expressed S100 and vimentin, confirming a diagnosis of a malignant peripheral nerve sheath tumour (PNST). To the best of our knowledge, this is the first report of a primary malignant PNST in the urinary bladder of a dog.

Simple manoeuvre to reduce the overlap between the internal jugular vein and carotid artery in infants.

BACKGROUND: Catheterisation of the internal jugular vein (IJV) can be difficult in infants. We aimed to evaluate whether a simple manoeuvre, a slight caudo-lateral traction of the ipsilateral arm (CLTIA), could decrease the head rotation-induced overlap of the IJV to the carotid artery (CA) in infants. METHODS: Twenty-five infants were included. The patients were placed in the 10° Trendelenburg position with a shoulder roll. On both sides of the neck, ultrasound images were obtained in a transverse orientation before and after the CLTIA at 0°, 40°, and 80° of head rotation, respectively. On each image, CA overlap was calculated as follows: CA overlap (%) = (overlap distance/CA diameter) × 100. RESULTS: The CLTIA decreased CA overlap (%) in 0°, 40°, and 80° of head rotation on the right side of the neck [14 (interquartile range, IQR 0-32) to 0 (IQR 0-14), 24 (IQR 0-46) to 0 (IQR 0-33), and 31 (IQR 12-58) to 23 (IQR 0-34); all P < 0.01] and on the left [29 (IQR 7-61) to 19 (IQR 0-44), 40 (IQR 21-65) to 31 (IQR 0-46), and 44 (IQR 29-97) to 33 (IQR 14-69); all P < 0.01], respectively. CONCLUSION: The CLTIA successfully reduced the overlap between the IJV and the CA in infants. However, further study should be needed to evaluate the clinical usefulness of the CLTIA during the IJV catheterisation.

Membrane association of a protein increases the rate, extent, and specificity of chemical cross-linking.

Many cellular processes involve interactions between membrane-associated proteins, and those interactions are enhanced by membrane association. We have used cross-linking reactions to compare the extent and specificity of protein interactions in solution versus on a membrane surface. Cysteine mutants of a soluble cytoplasmic fragment (CF) of the aspartate receptor, a transmembrane receptor involved in bacterial chemotaxis, are used in disulfide bond formation with the thiol-specific oxidant diamide and chemical cross-linking reactions with the trifunctional maleimide TMEA. CF binding to membranes is mediated by its N-terminal His tag binding to vesicles containing a nickel-chelating lipid, so cross-linking reactions conducted in the presence and absence of vesicles differ only in whether CF is bound to the vesicles or is free in solution. For multiple Cys throughout the CF, membrane association is shown to increase the rate and extent of these reactions. Cross-linking specificity, which is measured as the preference for cross-linking between Cys near each other in the native structure, is also enhanced by membrane association. These results provide an experimental demonstration that membrane binding enhances protein-protein interactions, an important consideration for understanding processes involving membrane-associated proteins. The experiments further demonstrate the importance of cross-linking conditions for these reactions that are often used to probe protein structure and dynamics and the potential of membrane association to restore native interactions of membrane-associated proteins for cross-linking studies.

Inhibition of tumour necrosis factor-alpha secretion from EpiDermTM tissues by a novel small molecule, UTL-5d.

BACKGROUND: UTL-5d [N-(4-chlorophenyl)-3-carboxyamidyl-5-methylisoxazole] is a small-molecule tumour necrosis factor (TNF)-alpha modulator being investigated for its potential in several immune-mediated diseases, including psoriasis. OBJECTIVES: We aimed to determine whether UTL-5d represents a potential antipsoriasis agent. METHODS: Firstly, a keratinocyte cell-based study was used to study the inhibition of TNF-alpha and gene suppression by UTL-5d in vitro. Secondly, a multilayered human epidermis tissue model, consisting of normal human-derived epidermal keratinocytes, was used to study the dose-dependent reduction of TNF-alpha by UTL-5d as well as the feasibility of using UTL-5d in a lotion formulation. RESULTS: The cell-based study showed that UTL-5d significantly reduced TNF-alpha secretion from keratinocytes (68% reduction at 17 mug mL(-1)) and suppressed JAK3 and MAP3K2 genes by 70% and 40%, respectively. In the human epidermis tissue model, reduction of TNF-alpha by UTL-5d appeared to be dose dependent (8.35-33.4 microg mL(-1)); UTL-5d also reduced cell death induced by ultraviolet (UV) B. Tissues treated by UTL-5d in a preliminary lotion formulation showed significant reduction of TNF-alpha induced by UVB. CONCLUSIONS: Our results indicate that UTL-5d may be worthy of further investigation for its potential as a topical agent for psoriasis.

Phenotypic and genetic antibiogram of methicillin-resistant staphylococci isolated from bovine mastitis in Korea.

Staphylococcus aureus belongs to the group of major contagious mastitis pathogens, whereas the coagulase-negative staphylococci (CNS) are also capable of causing opportunistic bovine mastitis. Many of these strains are resistant to penicillin or ampicillin because of the long-term use of beta-lactam antibiotics in agricultural and healthcare settings. Based on the simple and highly specific coagulase genotyping by PCR-RFLP used for discriminating among Staph. aureus strains, the relationship between phenotypic antibiogram and the polymorphism of coagulase gene was determined in this study. The staphylococci strains (835 Staph. aureus and 763 CNS) were isolated from 3,047 bovine mastitic milk samples from 153 dairy farms in 8 provinces from 1997 to 2004 in the Republic of Korea. Twenty-one (2.5%) Staph. aureus and 19 (2.4%) CNS strains were resistant to methicillin [oxacillin minimum inhibitory concentration (MIC) > or = 4 microg/mL]. The mecA gene was also found in 13 methicillin-resistant Staph. aureus (MRSA) and 12 methicillin-resistant CNS (MRCNS) isolates with a significantly higher detection rate of the mecA gene in MRSA with high MIC (> or = 16 microg/mL) compared with those with MIC < or = 8 microg/mL. Methicillin-resistant Staph. aureus and MRCNS were also more resistant to other antibiotics (ampicillin, cephalothin, kanamycin, and gentamicin) than methicillin-susceptible staphylococci. Among 10 different coa PCR-RFLP patterns (A to J) in 706 Staph. aureus strains, the main types were A (26.9%), B (17.0%), G (10.5%), and H (15.4%), with the frequent observation of the A and H types (6 and 10 isolates) in MRSA. This study indicates that major epidemic Staph. aureus clones may be spread between different dairy farms, and the profile of coa genotype can be applied for epidemiological investigations and control of bovine mastitis, particularly one caused by MRSA with specific prevalent coa types.

Observations on the Apparent Solubility of Carbonate-Apatites.

Previousreports indicating that the apparent solubilities of carbonate-apatites are low appear to conflict with findings that carbonate incorporation into the apatite structure tends to reduce stability. Carbonate-apatites were prepared by a precipitation method and by hydrolysis of monetite and brushite. Apparent solubility profiles were determined by measuring dissolution after exposure for 24 h to acetate buffers with known saturations with respect to hydroxyapatite. All preparations showed a range of apparent solubilities, in agreement with previous work. Precipitated samples had higher apparent solubilities than samples prepared by hydrolysis and this was correlated with differences in crystallinity. Further experiments showed that pyrophosphate ion reduced the apparent solubility, but it was concluded that pyrophosphate occurring naturally in synthetic apatites would be insufficient to cause low apparent solubilities. Microscopical observations showed that precipitated carbonate-apatites were composed of small crystals of uniform size, whereas carbonate-apatites prepared by hydrolysis consisted of both small crystals and very large crystals. The low apparent solubilities observed in the latter preparations are attributed to the large crystals. The surface phenomena possibly involved in apparent solubility behavior are discussed. Copyright 1999 Academic Press.

Dynamically Modified Torsional Eigenstates for Single-Top Molecules.

We present a semiclassical treatment for the inclusion of kinetic energy-dependent variations in the moment of inertia for certain molecules exhibiting internal rotational motion. The model is applied to trifluoroacetyl bromide and the resulting dynamically modified transition energies yield an improved spectral deviation in contrast to the rigid model. Copyright 1998 Academic Press.

Modified Morse Potential for Diatomic Molecules.

We present a diatomic potential which closely resembles the standard Morse function but incorporates additional flexibility for fitting experimental vibrational energy-gap data. This flexibility is accommodated by introducing a continuously variable radially dependent change in the exponent of the Morse function, which in practice is adequately realized via a relatively small number of constant parameters. As an illustration, the method is applied to calculate the quantum vibrational levels of the X1Sigma+g ground electronic state of the N2 molecule. Copyright 1998 Academic Press.

A Systematic Approach for Determining Internal Rotation Potentials of Single-Top Molecules from Observed Transition Spectra

We present a systematic technique for the calculation of quantum potentials which fit experimentally specified transition spectra. With the aid of examples involving the molecular torsion of single-top molecules, we show how via a very small number of iterations, the observed spectrum may be approached to within a minimal deviation. Copyright 1997 Academic Press. Copyright 1997Academic Press