Computer-assisted grading of adenocarcinoma in prostatic aspirates

Conventional cytologic grading of fine needle aspirates of prostatic adenocarcinoma has been shown neither to be reproducible nor to correlate well with histologic grading. This study developed a tumor grade classification based on computerized cytomorphometric features and compared the results to conventional grading of companion tissue sections. The image analysis system evaluated architectural features of the aspirates (mainly cell cluster features and interrelationships) as well as nuclear features. Thirty-five prostatic adenocarcinomas (8 well, 19 moderately and 8 poorly differentiated) were evaluated. Discriminant functions based on data collected at medium and high resolution distinguished between aspirates from low-grade (well-differentiated) and high-grade (poorly differentiated) adenocarcinomas with 81% accuracy. Moderately differentiated cancers could not be classified as a distinct group. This study suggests that accurate grading of prostatic adenocarcinoma in fine needle aspirate smears requires the evaluation of medium-resolution features related to specimen cellularity and uniformity or crowding of cell clusters as well as of high-resolution features of nuclear area, perimeter and coarseness of chromatin texture. These findings are compared to those of other schemes for the cytologic grading of prostatic aspirates.     

Ribonucleic Acid Polymerase Induced in Cells Infected with Sendai Virus

A ribonucleic acid (RNA)-dependent RNA polymerase was induced in chick embryo fibroblast cells after infection with Sendai virus (parainfluenza 1 virus). The enzyme was associated with the microsomal fraction of infected cells and reached maximum detectable activity at 18 hr after virus infection. The activity of the enzyme in vitro was dependent on the presence of added magnesium ions and all four nucleoside triphosphates and was not inhibited by actinomycin D. The RNA synthesized by the enzyme in vitro was sensitive to ribonuclease and consisted of a complex mixture of RNA species including 34S, 24S, and 18S components. Similar RNA components were detected in the microsomal fraction of Sendai virus-infected cells by labeling with (3)H-uridine from 17 to 18 hr postinfection in the presence of actinomycin D. Of the RNA synthesized by Sendai virus-induced RNA polymerase in vitro, 98% became insensitive to ribonuclease after annealing with RNA extracted from purified Sendai virus particles.     

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

Background and methods

Human metapneumovirus (hMPV) is a recently discovered respiratory virus associated with bronchiolitis, pneumonia, croup and exacerbations of asthma. Since respiratory viruses are frequently detected in patients with acute exacerbations of COPD (AE-COPD) it was our aim to investigate the frequency of hMPV detection in a prospective cohort of hospitalized patients with AE-COPD compared to patients with stable COPD and to smokers without by means of quantitative real-time RT-PCR.

Results

We analysed nasal lavage and induced sputum of 130 patients with AE-COPD, 65 patients with stable COPD and 34 smokers without COPD. HMPV was detected in 3/130 (2.3%) AE-COPD patients with a mean of 6.5 × 10⁵ viral copies/ml in nasal lavage and 1.88 × 10⁵ viral copies/ml in induced sputum. It was not found in patients with stable COPD or smokers without COPD.

Conclusion

HMPV is only found in a very small number of patients with AE-COPD. However it should be considered as a further possible viral trigger of AE-COPD because asymptomatic carriage is unlikely.     

Effect of Metalaxyl on the incidence and severity of Pearl millet downy mildew disease in Northern Nigeria

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight.     

A C-type lectin from the tunicate, Styela plicata, that modulates cellular activity

Previous studies have identified proteins from tunicates (invertebrate members of the Phylum Chordata) that have physicochemical and functional properties similar to those of the inflammatory cytokine, interleukin 1 (IL-1). Here we characterize one of those proteins from the tunicate, Styela plicata, that can stimulate tunicate and mammalian cell proliferation, activate phagocytosis, increase interleukin 2 (IL-2) secretion by mammalian peripheral blood mononuclear cells and enhance IL-2 receptor (IL-2R) expression by mammalian EL-4.IL-2 cells. Partial amino acid sequence data showed that the S. plicata protein resembles three C-type lectins (TC14, TC14-1 and TC14-2) from a closely related tunicate species, Polyandrocarpa misakiensis. Its similarity to carbohydrate recognition domains (CRDs) from P. misakiensis lectins suggests that the S. plicata protein modulates the activities of mammalian immunocompetent cells by interacting with carbohydrate moieties of glycosylated cell surface receptors.     

Establishment of the cat flea (Ctenocephalides felis felis) on the ferret (Mustela putorius furo) and its control with imidacloprid

As the ferret, Mustela putorius furo L. (Carnivora: Mustelidae), is becoming increasingly popular as a pet animal and as it is susceptible to the cat-flea, Ctenocephalides felis felis Bouché (Siphonaptera: Pulicidae), an experimental model was established for evaluating insecticidal treatments on this host. A high establishment rate (76.7-91.8%) was recorded when 60 unfed adult C. felis were placed on ferrets. This provided an adequate infestation for chemotherapeutic evaluation without causing undue discomfort to the host. Twelve ferrets were allocated to two groups matched for sex and individual ability to sustain a flea population. One group was treated topically with an imidacloprid spot-on formulation at a dose rate of 10 mg/kg body-weight on Day 0. All ferrets were infested with C. felis on Days -1, 7, 14, 21 and 28, and flea counts were performed 8 and 24 h post-treatment and one day after each subsequent infestation. Fleas were removed at all but the 8 h count (when they were returned to their host). Flea burdens were reduced by 95.3% (P < 0.001) within 8 h of treatment and 100% efficacy was recorded at 24 h. At 1, 2, 3 and 4 weeks post-treatment, protection against re-infestation was 92.9% (P < 0.001), 55.7% (P < 0.02), 18.3% (NS) and 7.4% (NS), respectively. Thus, at this dose rate, imidacloprid gave excellent efficacy against a resident C. felis population and provided a high level of residual activity for at least one week after treatment.     

Formation of micronuclei in erythrocytes of the fathead minnow (Pimephales promelas) after acute treatment with mitomycin C or cyclophosphamide

Despite the widespread use of the fathead minnow in ecotoxicology, there have been relatively few studies on genotoxicity biomarkers in this small, warm-water fish species. Consequently, we investigated the effect of two known genotoxins, mitomycin C and cyclophosphamide, on micronucleus induction in spleen and peripheral blood erythrocytes of this species. Initially, 96-h experiments after intra-peritoneal (i.p.) injections of mitomycin C and cyclophosphamide were undertaken to determine the maximum tolerated dose (MTD). From these studies, MTDs of 10 and 400 mg/kg, respectively, were obtained: doses that were higher than those reported for other fish species. Next, an assessment of micronucleus induction at 1, 2, 4, 8 and 14 days after injection was undertaken for each compound at the MTD. Mitomycin C at 10 mg/kg significantly induced micronuclei in erythrocytes from the spleen, but not from the peripheral blood, at 8 and 14 days. In addition, the overall levels of micronuclei observed were lower than most previously published data from other fish species. In contrast to mitomycin C, treatment with 400 mg/kg cyclophosphamide failed to significantly induce micronuclei in erythrocytes from any of the tissues employed, in contrast to previous reports of significant induction in other species. The reasons for the apparent relative insensitivity of the fathead minnow to these clastogens, with respect to both MTDs and micronucleus induction, are not clear. The fathead minnow, however, has previously been described as relatively insensitive compared to other fish species with respect to selected carcinogens and cytochrome P450 inducers; the latter suggesting that the lack of a significant induction following cyclophosphamide exposure may be due to low metabolic activation in vivo. Consequently, further clarifying work is required to delineate the response shown, considering the extensive use of this species in ecotoxicology research and regulatory testing.     

A 3D interactive method for estimating body segmental parameters in animals: application to the turning and running performance of Tyrannosaurus rex

We developed a method based on interactive B-spline solids for estimating and visualizing biomechanically important parameters for animal body segments. Although the method is most useful for assessing the importance of unknowns in extinct animals, such as body contours, muscle bulk, or inertial parameters, it is also useful for non-invasive measurement of segmental dimensions in extant animals. Points measured directly from bodies or skeletons are digitized and visualized on a computer, and then a B-spline solid is fitted to enclose these points, allowing quantification of segment dimensions. The method is computationally fast enough so that software implementations can interactively deform the shape of body segments (by warping the solid) or adjust the shape quantitatively (e.g., expanding the solid boundary by some percentage or a specific distance beyond measured skeletal coordinates). As the shape changes, the resulting changes in segment mass, center of mass (CM), and moments of inertia can be recomputed immediately. Volumes of reduced or increased density can be embedded to represent lungs, bones, or other structures within the body. The method was validated by reconstructing an ostrich body from a fleshed and defleshed carcass and comparing the estimated dimensions to empirically measured values from the original carcass. We then used the method to calculate the segmental masses, centers of mass, and moments of inertia for an adult Tyrannosaurus rex, with measurements taken directly from a complete skeleton. We compare these results to other estimates, using the model to compute the sensitivities of unknown parameter values based upon 30 different combinations of trunk, lung and air sac, and hindlimb dimensions. The conclusion that T. rex was not an exceptionally fast runner remains strongly supported by our models-the main area of ambiguity for estimating running ability seems to be estimating fascicle lengths, not body dimensions. Additionally, the craniad position of the CM in all of our models reinforces the notion that T. rex did not stand or move with extremely columnar, elephantine limbs. It required some flexion in the limbs to stand still, but how much flexion depends directly on where its CM is assumed to lie. Finally we used our model to test an unsolved problem in dinosaur biomechanics: how fast a huge biped like T. rex could turn. Depending on the assumptions, our whole body model integrated with a musculoskeletal model estimates that turning 45 degrees on one leg could be achieved slowly, in about 1-2s.     

Inhibitors of HCV NS5B polymerase: synthesis and structure-activity relationships of unsymmetrical 1-hydroxy-4,4-dialkyl-3-oxo-3,4-dihydronaphthalene benzothiadiazine derivatives

Substituted 1-hydroxy-4,4-dialkyl-3-oxo-3,4-dihydronaphthalene benzothiadiazine derivatives were investigated as inhibitors of genotype 1 HCV polymerase. Structure-activity relationship patterns for this class of compounds are discussed. It was found that the saturated alkane dialkyl units provided the most active analogs.