Phosphaturic Mesenchymal Tumors in the Head and Neck Demonstrate a Broad Clinical and Morphologic Spectrum.

Phosphaturic mesenchymal tumour (PMT) is a rare tumour that occurs in bone or soft tissue and is associated with production of fibroblast growth factor 23 (FGF23) leading to tumor-induced osteomalacia. We report three cases of PMT involving the head and neck that highlight the broad spectrum of clinical and histologic features of PMT. One of these lesions from the hard palate demonstrated an admixture of epithelial and mesenchymal elements, a feature that can pose a diagnostic challenge. The diagnostic utility of immunohistochemistry including FGF23, somatostatin receptor 2A, SATB2, ERG and CD56 is discussed. The biochemical pathway in the development of PMT associated tumor induced osteomalacia and its role in investigations and management of PMT is also described.

Abnormal preschool Lung Clearance Index (LCI) reflects clinical status and predicts lower spirometry later in childhood in cystic fibrosis.

BACKGROUND: Clinical and prognostic value of preschool Multiple Breath Washout (MBW) remains unclear. METHODS: Initial MBW results (Exhalyzer® D, EcoMedics AG) in preschool Cystic Fibrosis (CF) subjects (age 2-6 years) at a time of clinical stability were compared to (1) concurrent clinical status measures and (2) later spirometry outcomes. Abnormal Lung Clearance Index (LCI) was defined using published reference data (ULN for LCI 8.0). RESULTS: LCI was abnormal in 56% (28/50), with mean (SD) LCI 8.61(1.85) at age 4.71(1.3) years. Abnormal LCI was associated with higher dornase alfa use, previous positive bacterial cultures and pF508.del homozygous genotype. Later spirometry (n = 44; mean (SD) 2.3(0.5) years after MBW) demonstrated that abnormal initial preschool LCI was a strong predictor of lower later spirometry outcomes. CONCLUSION: Abnormal preschool LCI was associated with concurrent measures of clinical status and later spirometry deficits, suggesting early prognostic utility of MBW testing in this age range.

Implications of CT noise and artifacts for quantitative 99mTc SPECT/CT imaging.

PURPOSE: This paper evaluates the effects of computed tomography (CT) image noise and artifacts on quantitative single-photon emission computed-tomography (SPECT) imaging, with the aim of establishing an appropriate range of CT acquisition parameters for low-dose protocols with respect to accurate SPECT attenuation correction (AC). METHODS: SPECT images of two geometric and one anthropomorphic phantom were reconstructed iteratively using CT scans acquired at a range of dose levels (CTDIvol = 0.4 to 46 mGy). Resultant SPECT image quality was evaluated by comparing mean signal, background noise, and artifacts to SPECT images reconstructed using the highest dose CT for AC. Noise injection was performed on linear-attenuation (µ) maps to determine the CT noise threshold for accurate AC. RESULTS: High levels of CT noise (σ ∼ 200-400 HU) resulted in low µ-maps noise (σ ∼ 1%-3%). Noise levels greater than ∼ 10% in 140 keV µ-maps were required to produce visibly perceptible increases of ∼ 15% in (99m)Tc SPECT images. These noise levels would be achieved at low CT dose levels (CTDIvol = 4 µGy) that are over 2 orders of magnitude lower than the minimum dose for diagnostic CT scanners. CT noise could also lower (bias) the expected µ values. The relative error in reconstructed SPECT signal trended linearly with the relative shift in µ. SPECT signal was, on average, underestimated in regions corresponding with beam-hardening artifacts in CT images. Any process that has the potential to change the CT number of a region by ∼ 100 HU (e.g., misregistration between CT images and SPECT images due to motion, the presence of contrast in CT images) could introduce errors in µ140 keV on the order of 10%, that in turn, could introduce errors on the order of ∼ 10% into the reconstructed (99m)Tc SPECT image. CONCLUSIONS: The impact of CT noise on SPECT noise was demonstrated to be negligible for clinically achievable CT parameters. Because CT dose levels that affect SPECT quantification is low (CTDIvol ∼ 4 µGy), the low dose limit for the CT exam as part of SPECT/CT will be guided by CT image quality requirements for anatomical localization and artifact reduction. A CT technique with higher kVp in combination with lower mAs is recommended when low-dose CT images are used for AC to minimize beam-hardening artifacts.

Evaluation of the new API 20C strip for yeast identification against a conventional method.

The new API 20C yeast identification system together with appropriate microscopic morphology determinations achieved a 97% correlation with a rapid conventional method. Whereas a group composed of Candida, Torulopsis, Saccharomyces, and Rhodotorula was identified with ease (98% overall correlation), a second group, containing Cryptococcus, Trichosporon, and Geotrichum species, appeared to give the system the most difficulty (90% correlation). Within this group particular difficulty was encountered in identifying varieties of Cryptococcus albidus, C. terreus, C. laurentii, Trichosporon beigelli, and Geotrichum spp. as to species. The API 20C system should be incubated the full 72 h prescribed by the manufacturer. However, when used in conjunction with appropriate morphological tests, presumptive identifications of some Candida and Torulopsis species may be made at 24 to 48 h. To facilitate identifications of the more difficult group of yeasts, ancillary tests for determining nitrate reductase, urease, and phenol oxidase activities should be considered as additions to the strip. Incorporating the phenol oxidase test would be especially important for identification of Cryptococcus neoformans, a yeast which should be identified as quickly and as accurately as possible. The API 20C system with computer assistance has proved to be an easy-to-inoculate, versatile, and fairly rapid method of yeast identification, giving results comparable to those obtained by conventional methodologies.

In vitro antimicrobial activity of some cyclic hydroxamic acids and related lactams.

Against Enterobacter aerogenes 13048, Serratia marcescens 13880, Klebsiella pneumoniae 10031, Pseudomonas aeruginosa 10145, Escherichia coli 9723, Lactobacillus casei 7469, Lactobacillus plantarum 8014, Leuconostoc dextranicum 8086, and Streptococcus faecalis 8043, the mean minimal inhibitory concentrations of three cyclic hydroxamic acids, 3-amino-3,4-dihydro-1-hydroxycarbostyril, the 6-chloro analog, and the 7-chloro analog, were 0.6, 0.6, and 0.2 micrograms/ml, and those of the corresponding lactams, 3-amino-3,4-dihydrocarbostyril, the 6-chloro analog, and the 7-chloro analog, were 60, 60, and 6 micrograms/ml, respectively. Under the same assay conditions the mean minimal inhibitory concentrations of chloramphenicol and kanamycin were both 2 micrograms/ml. In addition, the cyclic hydroxamic acids but not the lactams inhibited the growth of Candida albicans at minimal inhibitory concentrations ranging from 20 to 200 micrograms/ml, at pH 7, as compared with that of amphotericin B, at 2 micrograms/ml.

Synthesis and microbiological activities of beta-(1-chloro-2-naphthyl) alanine and beta-(1-bromo-2-naphthyl) alanine.

beta-(1-Chloro-2-naphthyl)alanine and beta-(1-bromo-2-naphthyl) alanine were synthesized by ammonolysis of the corresponding alpha, 1-dihalo-2-naphthalenepropanoic acids derived from 1-nitro-2-naphthylamine by diazotization and condensation with acrylic acid in the presence of cuprous halides. The two analogs as well as the previously reported beta-(2-naphthyl)alanine and beta-(1-naphthyl)alanine were studied as growth inhibitors of Escherichia coli 9723, Leuconostoc dextranicum 8086, and Lactobacillus plantarum 8014. In general, the chloro and bromo analogs were more effective than the unsubstituted naphthylalanines as growth inhibitors of the three microorganisms studied.

Synthesis and antibacterial activities of some chloro analogs of 3 amino-3,4-dihydro-1-hydroxycarbostyril.

The effects of a chloro substituent upon the microbiological activities of 3-amino-3,4-dihydro-1-hydroxycarbostyril were determined. The 5-, 6-, and 7-chloro analogs were synthesized by reductive cyclizations of the appropriately chloro-substituted o-nitrophenylalanines, while the 8-chloro analog was obtained from the N-trifluoroacetyl-3-chloro-2-nitrophenylalanine ethyl ester. All of these compounds were observed to inhibit the growth of Escherichia coli 9723, Leuconostoc dextranicum 8086, and Lactobacillus plantarum 8014. The relative inhibitory activities of the chloro analogs were 7-Cl greater than 6-Cl greater than 8-Cl greater than 5-Cl in E. coli and 7-Cl greater than 6-Cl greater than 8-Cl = 5-Cl in L. dextranicum and L. plantarum. In each of the three microorganisms, the 7-Cl analog was a more effective growth inhibitor than the parent unsubstituted compound. The growth inhibitory activities of this class of compounds were demonstrated to be much more effective than those of the four corresponding lactams, the 5-, 6-, 7-, and 8-chloro analogs of 3-amino-3,4-dihydrocarbostyril.

Synthesis and microbiological activities of some monohalogenated analogs of tyrosine.

2-Chlorotyrosine and 2-bromotyrosine, as well as the previously reported 2-fluorotyrosine, were synthesized by hydrolysis of the condensation products from the appropriate benzyl bromide and ethyl acetamidomalonate and were compared with the corresponding 3-halotyrosines as growth inhibitors of Escherichia coli 9723, Streptococcus faecalis 8043 and Lactobacillus plantarum 8014. In contrast to the 2- and 3-fluorotyrosines which were equally effective as growth inhibitors, the 2-chloro- and 2-bromotyrosines were much more effective than the 3-chloro- and 3-bromotyrosines in inhibiting the growth of the three microorganisms. For each of the assay organisms, the growth inhibitions of all three 2-halotyrosines were reversed competitively in varying degrees by tyrosine.

Theory of thermal imaging using infrared to visible image up-conversion.

A novel method of thermal imaging based on the up-conversion of infrared radiation in nonlinear optical crystals is analyzed. An equation is derived giving the temperature resolution in terms of the pump laser energy E(p). For a proustite-ruby system based on the 8-13-micro band, a temperature resolution of better than 1 degrees C is predicted when the number of resolvable spots is 100 x 100 and E(p) = 10 J. Numerical results are also provided for eighteen possible systems having different combinations of pump laser (neodymium or ruby), infrared band (3-5 micro or 8-13 micro), nonlinear crystal (Ag(3)AsS(3), AgGas(2), ZnGeP(2), or LiNbO(3)), and imaging photocathode [S-1, S-20, GaAs/(Cs,O), or In(As,P)/(Cs,O)].