Extranodal lymphoma in the thorax: cross-sectional imaging findings.

The purpose of this review is to discuss and illustrate the spectrum of appearances of extranodal lymphoma in the thorax, including the lungs, pleura, heart, thymus, chest wall, thoracic spine, and breast, using current cross-sectional imaging techniques, such as multidetector computed tomography, positron-emission tomography/computed tomography, magnetic resonance imaging, and sonography. Extranodal lymphoma can affect any organ or tissue in the thorax, and can be mistaken for other inflammatory or neoplastic conditions. This review should alert the radiologist to consider extranodal lymphoma in the appropriate clinical setting to ensure timely diagnosis, correct staging, and accurate post-treatment evaluation to optimize treatment regimens.

Imaging findings of unusual anorectal and perirectal pathology: a multi-modality approach.

The objective of this review is to discuss the less common causes of rectal and perirectal disease with an emphasis on their differentiating radiological features and the importance of a multimodality imaging approach. Radiologists should be aware of the ultrasound, computed tomography, and magnetic resonance imaging appearances of the wide variety of uncommon lesions arising from the rectal and perirectal regions that may simulate adenocarcinoma in order to render an accurate diagnosis and facilitate appropriate management.

Prevalence of imaginary companions in a normal child population.

Approximately 1800 children between the ages of 5 and 12 years were randomly selected and asked whether they had present or past experiences of imaginary companions. It was found that 829 (46.2%) children reported experiences of imaginary companions. These findings were unexpected as previous studies had suggested that imaginary companions are generally experienced by fewer, much younger children. There were no significant differences in creativity scores between children who reported imaginary companions compared with those who did not. Imaginary companions were reported by more girls than boys, and were not restricted to very young children.

The utility of dimensional and categorical approaches to understanding dissociation in the eating disorders.

OBJECTIVE: The present study compared levels of dissociation across groups of eating-disordered women, investigating the utility of dimensional and categorical measures of dissociation in understanding diagnoses and behaviours in the eating disorders. METHODS: The Dissociative Experiences Scale (DES-II) was completed by 170 eating-disordered women (drawn from out-patient assessment clinics) and 203 nonclinical women. The clinical group also supplied information regarding eating behaviours and related features (alcohol abuse, reported history of sexual abuse). The DES-II and a subset of its items (DES-Taxon) were used as dimensional and categorical discriminators of the groups and of the presence/absence of specific features and symptoms. RESULTS: When treated as dimensional measures, the DES-II and DES-Taxon had similar levels of clinical utility (particularly discriminating the binge-purge anorexics from the other clinical groups). However, the DES-Taxon was a superior categorical measure, discriminating groups more clearly and predicting the presence of many symptoms and features much more powerfully. CONCLUSIONS: The DES-Taxon is a potentially valuable self-report measure for indicating the level and presence of dissociative psychopathology in the eating disorders. As well as being convenient to administer and score, it has the clinical and research value of indicating those patients in whom treatment might need to include addressing pathological dissociation.

Adenovirus type 2 DNA replicated in arginine-starved KB cells is infectious.

Adenovirus type 2 DNA from extracts of KB cells rendered nonpermissive by arginine starvation is infectious.

Arginine deprivation in KB cells. I. Effect on cell cycle progress.

When exponentially growing KB cells were deprived of arginine, cell multiplication ceased after 12 h but viability was maintained throughout the experimental period (42-48 h). Although tritiated thymidine ([(3)H]TdR) incorporation into acid-insoluble material declined to 5 percent of the initial rate, the fraction of cells engaged in DNA synthesis, determined by autoradiography, remained constant throughout the starvation period and approximately equal to the synthesizing fraction in exponentially growing controls (40 percent). Continous [(3)H]TdR-labeling indicated that 80 percent of the arginine-starved cells incorporated (3)H at some time during a 48-h deprivation period. Thus, some cells ceased DNA synthesis, whereas some initially nonsynthesizing cells initiated DNA synthesis during starvation. Flow microfluorometric profiles of distribution of cellular DNA contents at the end of the starvation period indicated that essentially no cells had a 4c or G2 complement. If arginine was restored after 30 h of starvation, cultures resumed active, largely asynchronous division after a 16-h lag. Autoradiographs of metaphase figures from cultures continuously labeled with [(3)H]TdR after restoration indicated that all cells in the culture underwent DNA synthesis before dividing. It was concluded that the majority of cells in arginine-starved cultures are arrested in neither a normal G1 nor G2. It is proposed that for an exponential culture, i.e. from most positions in the cell cycle, inhibition of cell growth after arginine with withdrawal centers on the ability of cells to complete replication of their DNA.

Arginine deprivation in KB cells. II. Characterization of the DNA synthesized during starvation.

DNA synthesis in cells deprived of arginine was examined. Three lines of evidence indicated that tritiated thymidine ([3H]TdR) incorporation in arginine-starved cells was due to replicative rather than repair DNA synthesis. (a) When made in the presence of bromodeoxyuridine, the [3H]TdR-labeled DNA sedimented at hybrid density in isopycnic gradients. (b) As determined by the diphenylamine reaction, there was a 15% increase in the chemical amount of DNA per culture 30 h after arginine deprivation. (c) [3H]TdR incorporation was hydroxyurea-sensitive. Alkaline velocity sedimentation of the total DNA made during starvation revealed the existence of two distinct size classes: most of the DNA sedimented at a position analogous to that of control DNA, but 40% migrated one-third the distance of the bulk. After arginine restoration, these shorter pieces appeared to be chased into DNA of normal length; thus, one lesion in deprived cultures may cause an arrest in completion of DNA stretches to mature size. These findings, together with results of morphological studies of starved cells, suggest that changes induced by arginine deficiency effect the organization of nucleoproteins. These changes are reversible upon arginine restoration.

Continued initiation of DNA synthesis in arginine-deprived Chinese hamster ovary cells.

When exponentially growing CHO cells were deprived of arginine (Arg), cell multiplication ceased after 12 h, but initiation of DNA synthesis continued: after 48 h of starvation with continuous [3H]thymidine exposure, 85% of the population had incorporated label, as detected autoradiographically. Consideration of the distribution of exponential cells in the various cell cycle phases leads to a calculation that most cells in G1 at the time that Arg was removed, as well as those in S, engaged in some DNA synthesis during starvation. In contrast, isoleucine (Ile)-starved cells did not initiate DNA synthesis, as has been reported by others. Experiments with cells synchronized by mitotic selection confirmed this difference in Arg- and Ile- deprived behavior, but also showed that cells which underwent the mitosis leads to G1 transition during Arg starvation remained arrested in G1 (G0?). The results suggest that Arg-deprived cells continue to maintain some proliferative function(s) while Ile-deprived cells do not.

Adenovirus tumorigenesis: role of the viral genome in determining tumor morphology.

Adenovirus type 12 transforms the fibroblastic BHK21 (baby hamster kidney) cell line into rounded or cuboidal cells that give rise in hamsters to undifferentiated small cell sarcomas indistinguishable from those induced in newborn hamsters by inoculation of the virus itself. In contrast. cells from this line transformed by polyoma virus retain their fibroblastic morphology and induce fibrosarcomas in hamsters. This suggests that the morphology of tumors induced by the adenovirus-transformed cells from this line may be determined by the viral genome and that such mechanism may also explain the remarkably uniform microscopic appearance which seems to characterize tumors induced in hamsters by direct inoculation of adenovirus type 12.