Major internal nuclear matrix proteins are common to different human cell types

Cancer invasion and metastasis are associated with matrix degradation. We describe a novel in vivo model of invasion by squamous epithelial neoplastic cells derived from transgenic mice grown on acellular human dermis. Human dermis was subjected to multiple freeze-thaw cycles to render it acellular, maintaining the basement membrane of the former dermal-epidermal junction. Cells representing discrete stages of a multistep transgenic mouse model of epidermal carcinogenesis (neonatal transgenic keratinocytes, moderately/poorly differentiated squamous cell carcinoma, and lymph node metastasis) were seeded onto the basement membrane surface, grown in culture for 4 days, grafted in a subpannicular pocket of athymic mice, and harvested after 3 weeks. Histological analysis demonstrated that neonatal transgenic keratinocytes did not degrade the basement membrane or invade the underlying dermis. In contrast, malignant cells derived from both a moderately differentiated squamous carcinoma and a lymph node metastasis were highly invasive. Immunohistochemical analysis revealed collagenase only in nests of invading malignant cells in contact with the dermal matrix, but not in the tumor mass remaining above the basement membrane, suggesting that this proteinase may be required for stromal invasion. This novel model recapitulates the events seen in malignant invasion: transgenic keratinocytes are unable to penetrate the dermis while cells from a moderately differentiated carcinoma and from lymph node metastasis consistently invade.     

Comparison of clinical diagnosis and standard laboratory and molecular methods for the diagnosis of genital ulcer disease in Lesotho: association with human immunodeficiency virus infection

A multiplex polymerase chain reaction (M-PCR) assay for Haemophilus ducreyi, Treponema pallidum, and herpes simplex virus (HSV) was compared with clinical and standard laboratory methods for the diagnosis of genital ulcer disease (GUD) in 105 patients; 36% were human immunodeficiency virus (HIV)-seropositive. Chancroid (80%), syphilis (8%), and genital herpes (8%) were the most frequent diagnoses. H. ducreyi and HSV were isolated from ulcers of 43% and 18% of patients, respectively; in 35%, all cultures were negative and the laboratory diagnosis indeterminate. M-PCR detected H. ducreyi, T. pallidum, and HSV in 56%, 23%, and 26% of patients, respectively; (no definitive diagnosis, 6%). The proportion of patients with more than one agent was 4% by culture and 17% by M-PCR (P = .002). Resolved sensitivities of M-PCR for H. ducreyi and HSV cultures were 95% and 93%, respectively. The sensitivities of H. ducreyi and HSV cultures were 75% and 60%, respectively. HSV, detected in 47% of specimens from HIV-infected versus 16% from HIV-uninfected patients (P < .001), may be emerging as a more frequent cause of GUD.     

My workplace: Intervention Center, Rikshospitalet. Expert gathering over children with heart disease

Intensity of vasopressin gene expression was compared in neurosecretory cells of supraoptic, postoptic, paraventricular and 6 accessory nuclei (extrahypothalamic included) of adult intact Wistar rats to study the morphofunctional specialization of magnocellular hypothalamic nuclei. Messenger RNA (mRNA) was revealed by radioautographic in situ hybridization, using 35S labelled exonic-intronic probe. By densitometry the amount of label was shown not to differ significantly in neurosecretory cells of all nuclei studied. The latter reflects similar basal level of vasopressin gene expression in all magnocellular nuclei of intact rats. The explanations of this fact as well as possible perspectives of studying molecular biological basis of functional specialization of different magnocellular hypothalamic formations are discussed.     

Extensive genomic conservation of cattle microsatellite heterozygosity in sheep

We report the evaluation of 1036 bovine microsatellite primer pairs for their suitability as linkage markers in sheep. Approximately 58% (605/1036) of bovine primer pairs amplified a locus in sheep. Sixty-seven per cent (409/605) of amplified loci were detected as polymorphic. Marker heterozygosity, allele number and range of allele sizes were significantly lower in sheep than cattle sampled in this study. However, median fragment size was similar. These data suggest that high-resolution comparative linkage maps between closely related species can be constructed relatively efficiently.     

NG2 proteoglycan and the actin-binding protein fascin define separate populations of actin-containing filopodia and lamellipodia during cell spreading and migration

The transmembrane proteoglycan NG2 is able to interact both with components of the extracellular matrix and with the actin cytoskeleton. An examination of the distribution of NG2 during cell spreading suggests that NG2 can associate with two distinct types of actin-containing cytoskeletal structures, depending on the nature of the stimulus derived from the substratum. On fibronectin-coated dishes, cell surface NG2 associates exclusively with stress fibers developing within the cell. On poly-L-lysine-coated dishes, cell surface NG2 is associated with radial processes extending from the cell periphery. Spreading on fibronectin/poly-L-lysine mixtures, as well as on matrix components such as laminin, tenascin, and type VI collagen, produces cells with mosaic characteristics, i.e., NG2 is associated with both types of structures. NG2-positive radial processes are distinct from a second population of radial structures that contain fascin. NG2-positive extensions appear to be individual self-contained units (filopodia), whereas fascin is associated with actin ribs within sheets of membrane (lamellipodia). NG2- and fascin-positive structures are often localized to opposite poles of spreading cells, suggesting a possible role for the two classes of cellular extensions in the establishment of cell polarity during morphogenesis or migration. Time lapse imaging confirms the presence of lamellipodia on the leading edges of migrating cells, while numerous filopodia are present on trailing edges.     

Maintaining excellence: deliberate practice and elite performance in young and older pianists

Two studies investigated the role of deliberate practice in the maintenance of cognitive-motor skills in expert and accomplished amateur pianists. Older expert and amateur pianists showed the normal pattern of large age-related reductions in standard measures of general processing speed. Performance on music-related tasks showed similar age-graded decline for amateur pianists but not for expert pianists, whose average performance level was only slightly below that of young expert pianists. The degree of maintenance of relevant pianistic skills for older expert pianists was predicted by the amount of deliberate practice during later adulthood. The role of deliberate practice in the active maintenance of superior domain-specific performance in spite of general age-related decline is discussed.     

Organization of the visual reticular thalamic nucleus of the rat

The visual sector of the reticular thalamic nucleus has come under some intense scrutiny over recent years, principally because of the key role that the nucleus plays in the processing of visual information. Despite this scrutiny, we know very little of how the connections between the reticular nucleus and the different areas of visual cortex and the different visual dorsal thalamic nuclei are organized. This study examines the patterns of reticular connections with the visual cortex and the dorsal thalamus in the rat, a species where the visual pathways have been well documented. Biotinylated dextran, an anterograde and retrograde tracer, was injected into different visual cortical areas [17; rostral 18a: presumed area AL: (anterolateral); caudal 18a: presumed area LM (lateromedial); rostral 18b: presumed area AM (anteromedial); caudal 18b: presumed area PM (posteromedial)] and into different visual dorsal thalamic nuclei (posterior thalamic, lateral geniculate nuclei), and the patterns of anterograde and retrograde labelling in the reticular nucleus were examined. From the cortical injections, we find that the visual sector of the reticular nucleus is divided into subsectors that each receive an input from a distinct visual cortical area, with little or no overlap. Further, the resulting pattern of cortical terminations in the reticular nucleus reflects largely the patterns of termination in the dorsal thalamus. That is, each cortical area projects to a largely distinct subsector of the reticular nucleus, as it does to a largely distinct dorsal thalamic nucleus. As with each of the visual cortical areas, each of the visual dorsal thalamic (lateral geniculate, lateral posterior, posterior thalamic) nuclei relate to a separate territory of the reticular nucleus, with little or no overlap. Each of these dorsal thalamic territories within the reticular nucleus receives inputs from one or more of the visual cortical areas. For instance, the region to the reticular nucleus that is labelled after an injection into the lateral geniculate nucleus encompasses the reticular regions which receive afferents from cortical areas 17, rostral 18b and caudal 18b. These results suggest that individual cortical areas may influence the activity of different dorsal thalamic nuclei through their reticular connections.     

An outbreak of malignant catarrhal fever in young rusa deer (Cervus timorensis)

On the basis of clinical signs and histological findings eight 9-month-old male rusa deer (Cervus timorensis) were diagnosed with sheep associated-malignant catarrhal fever. Following a variable course involving rectal temperatures around 40.5 degrees C, depression, inappetence, diarrhoea, corneal opacity and hypopyon all animals died or were euthanased over a 5-week period. Severe multifocal vasculitis, mainly periglomerular and in the arcuate vessels were consistent histological findings which in the past have been adequate to confirm clinical diagnosis of sheep associated-malignant catarrhal fever. A nested polymerase chain reaction test has been used to detect a sheep associated-malignant catarrhal fever PRC product, 238 base-pairs in size, in DNA extracted from lymphocyte preparations. The result supported the diagnosis of sheep associated-malignant catarrhal fever in these deer.