Regional cerebral blood flow correlations of somatosensory areas 3a, 3b, 1, and 2 in humans during rest: a PET and cytoarchitectural study

The concept of functional connectivity relies on the assumption that cortical areas that are directly anatomically connected will show correlations in regional blood flow (rCBF) or regional metabolism. We studied correlations of rCBF of cytoarchitectural areas 3a, 3b, 1, and 2 in the brains of 37 subjects scanned with PET during a rest condition. The cytoarchitectural areas, delineated from 10 postmortem brains with statistical methods, were transformed into the same standard anatomical format as the resting PET images. In areas 3a, 3b, and 1, somatotopically corresponding regions were intercorrelated. Area 2 was correlated with the dorsal pre-motor area. These results were in accordance with the somatosensory connectivity in macaque monkeys. In contrast, we also found correlations between areas 3b and 1 with area 4a, and SMA, and among the left and right hand sector of areas 3a, 3b, and 1. Furthermore, there were no correlations between areas 3b, 1, and 2 with SII or other areas in the parietal operculum, nor of other areas known to be directly connected with areas 3a, 3b, 1, and 2 in macaques. This indicates that rCBF correlations between cortical areas during the rest state only partly reflect their connectivity and that this approach lacks sensitivity and is prone to reveal spurious or indirect connectivity.     

Gender differences in severity, symptomatology and distribution of melancholia in major depression

BACKGROUND: Studies of gender differences in the clinical presentation of depression have provided divergent results. This study aimed at analyzing gender differences in severity, symptomatology and distribution of melancholia in major depression. SAMPLING AND METHODS: The study comprised 930 in- and out-patients (652 women, 278 men) from 6 randomized controlled trials. All patients fulfilled DSM-III or DSM-III-R criteria for major depression. The 17-item Hamilton Depression Scale (HDS) was applied to all patients. A multi-axial evaluation was completed using the Newcastle 1 Depression Rating Scale from 1965 for melancholia (N1) in a subsample of patients (n = 439). A factor analysis on the HDS was performed. Non-parametric statistical tests were used and only gender differences greater than 20% were considered clinically relevant. RESULTS: The median on the HDS total score was 22 and the median number of symptoms was 13 for both men and women. Presentation of specific symptoms was similar for men and women. The factor analysis revealed no gender differences, and neither did analyses on symptoms of Axes II and IV. According to the N1, 80% of the men and 66% of the women suffered from melancholic depression (p = 0.004). CONCLUSIONS: In a large and broad sample of in- and out-patients with major depression, the severity and symptomatology of depression were similar for men and women. Melancholic depression was significantly more frequent among male than female patients. Inclusion and exclusion criteria in the randomized controlled trials provided a selected group of patients, which limited the generalisability of the results to an exclusive subgroup of patients treated for depression in routine clinical practice.     

Rapid genotyping of haemostatic gene polymorphisms using the 5' nuclease assay

Hemostatic gene polymorphisms have been shown to be associated with arterial and venous thrombotic disease. To date these polymorphisms have mainly been detected by labor-intensive conventional gel based methods. Aim of the present study was to design and optimize high throughput 5' nuclease assays for the detection of a set of 10 single-nucleotide polymorphisms (SNP) in genes of importance for hemostasis: plasminogen activator inhibitor type 1 -675 4G>5G, thrombin activatable fibrinolysis inhibitor Ala147Thr and 1,542C>G, beta-fibrinogen -455G>A, von Willebrand factor -1,051A>G, factor VII Arg353Gln, factor XIII Val34Leu, prothrombin 20,210G>A, tissue factor pathway inhibitor -287T>C, and methylenetetrahydrofolate reductase 1,298A>C. Specificity of each genotyping assay was confirmed by sequence-based typing and reproducibility was evaluated by repeated genotyping. The genotyping protocols presented here may serve as a valuable tool for clinical researchers interested in exploring associations between these SNPs and thrombotic disease.     

Role of phosphatidylinositol 3-kinase in neuronal survival and axonal outgrowth of adult mouse dorsal root ganglia explants

Adult ganglionic peripheral neurons have lost dependence on target-derived neurotrophin signaling for survival and regeneration after injury. To understand the mechanisms required to sustain such processes at maturity, we are studying neuronal survival and axonal outgrowth of adult mouse dorsal root ganglia (DRG) explants. We have here examined the role of phosphatidylinositol 3-kinase (PI3-K) activity. Both neuronal survival and axonal outgrowth of spontaneously growing preparations were decreased significantly by the PI3-K inhibitor LY294002 as was the increased outgrowth caused by nerve growth factor or glial cell line-derived factor. Inhibition of PI3-K activity promoted neuronal cell death to the same extent in the presence as in the absence of a growth factor, whereas inhibition of mitogen-activated protein kinase, MAPK, lacked effect. Using a compartmentalized system, it could be shown that only axonal outgrowth was decreased when the outgrowth region only was exposed to LY294002. Already-formed growth cones showed morphological changes within 5-10 min after exposure to LY294002. Akt (PKB) is one downstream effector of PI3-K. Immunofluorescence revealed the presence of activated Akt in DRG cell bodies and in axonal growth cones. Immunoreactivity was decreased by PI3-K inhibition. The results suggest that Akt is constitutively active in adult DRG neurons, and that PI3-K mediated processes are involved in neuronal survival of one or more DRG neuronal subpopulations and also in axonal elongation. The possible significance of Akt signaling for these effects is discussed.     

Human SP-A and a pharmacy-grade porcine lung surfactant extract can be reconstituted into tubular myelin--a comparative structural study of alveolar surfactants using cryo-transmission electron microscopy

Cryo-transmission electron microscopy (cryo-TEM) is a rather artefact-free method, well suited to study the alveolar surfactant system. A pharmacy grade porcine lung surfactant extract (HL-10) was mixed with human SP-A and Ringer's solution (for calcium ions), and it was shown by cryo-TEM that the tubular myelin (TM) type of structure was reconstituted. These aggregates were associated to liposomal aggregates, and resulted in macroscopic phase-separation. This phase showed a weak birefringence in the polarising microscope, which is characteristic for a liquid-crystalline type of structure. TM from rabbit lung lavage was also examined, and showed the same periodic arrangement of bilayers as alveolar surface layer from freshly cut rabbit lungs deposited directly on the cryo-TEM grids. The distance between the bilayers of TM was 40-50 nm, and an electron dense material, assumed to be SP-A, was sometimes seen to occur periodically along the bilayers, oriented perpendicularly to the tubuli. The results are consistent with the surface-phase model of the alveolar lining.     

Long-term socio-economic impact of vestibular schwannoma for patients under observation and after surgery

This study describes and compares the long-term socio-economic impact for patients diagnosed with a vestibular schwannoma and either operated on or observed. A consecutive sample of patients diagnosed with vestibular schwannoma in Denmark and either operated on (748 patients) or observed by the wait-and-re-scan policy (272 patients) during the period 1976-2000 were studied retrospectively. The consequences of operation/diagnosis (and observation) on vocational status, ability to handle daily chores and some psycho-social aspects were studied by means of a prospective postal questionnaire. Ninety-six per cent of the operated and 83 per cent of the observed patients answered the questionnaire. Overall, 34 per cent of operated patients resumed their daily activities within one to two months, and 76 per cent within four to six months. Patients operated on for a large tumour resumed their daily activities later than patients with a small tumour. Regardless of tumour size, employment was unchanged for the majority of observed and operated patients. The vocational consequences were significantly worse for operated patients with a large tumour, than for observed patients. However, no difference existed between the observed group and operated patients with a tumour below 20 mm in size. A change in vocational status was most frequent for assisting spouses, unskilled manual workers and the self-employed. The majority of both observed and operated patients experienced no change in their ability to handle daily chores. The changed ability of operated patients was worse than that of observed patients. Among various changes in their psycho-social well-being, decrease in social ability was the most frequent complaint in both groups, followed by increased fatigue, decreased concentration, increased irritability, depression and headache, decreased intellect and libido. Regardless of tumour size, the change in social ability, concentration and fatigue was worse for operated patients. Concerning headache, patients operated on for a large tumour were better off than observed patients and patients operated on for a small tumour. There was no difference between the operated and observed groups concerning irritability, intellect and libido. Deterioration of vocational status, ability to handle daily chores and several aspects of psycho-social well-being are reported both by patients operated on and observed for vestibular schwannoma. However, the negative changes were more frequent among the operated patients, although the differences were surprisingly modest, especially when comparing observed patients with patients operated on for a small tumour.     

Unexpected expansive paranasal sinus mucormycosis

Mucormycosis infection of the paranasal sinuses is a very rare but serious condition. Patients are usually immunocompromised by systemic disease. We report an unexpected case of expansive paranasal sinus mucormycosis in an immunocompetent European treated successfully with surgical debridement and intravenous amphotericin B. The pathogenesis, diagnosis and treatment of paranasal sinus mucormycosis is discussed.     

Prospects for delivery of recombinant angiostatin by cell-encapsulation therapy

Implantation of encapsulated nonautologous cells that have been genetically modified to secrete proteins with tumor suppressor properties represents an alternative nonviral strategy to cancer gene therapy. We report an approach to raise the yield of recombinant proteins from encapsulated cells substantially. We hypothesized that by optimizing the encapsulation procedure, the production efficacy from the encapsulated cells could be increased. HEK 293 EBNA cells were genetically engineered to produce angiostatin. Encapsulation was performed by varying bead size, cellular density, homogeneity, and ion composition of the gel. The morphology and viability of the cells and the release of angiostatin were studied. Computer software was developed for three-dimensional imaging and quantification of cell viability. Angiostatin production was assessed at 3, 6, and 11 weeks using enzyme-linked immunosorbent assay (ELISA). Inhomogeneous gels facilitated cell growth and viability. The most efficient inhomogeneous microcapsules were generated by reducing the size and cellular density of the beads. The viability and the production of angiostatin were 3 to 5 times higher than in the homogeneous capsules. Significant amounts of viable cells were present in both homogeneous and inhomogeneous beads after 6 months of culture. The stability of the alginate matrix was greatly enhanced by gelling in the presence of barium. In conclusion, the viability and production efficacy of recombinant angiostatin from alginate-encapsulated cells can be increased considerably by optimizing the encapsulation procedure. The development of such optimized microcapsules brings cell-encapsulation therapy further towards clinical use in cancer therapy.