Recovery of brain noradrenaline after 5,7-dihydroxytryptamine-induced axonal lesions in the rat

Time-dependent changes in regional CNS noradrenaline (NA) concentration, 3H-NA uptake and fluorescence morphology of CNS NA neurons were analysed in the adult rat up to 6 months after intraventricular injection of 5,7-dihydroxytryptamine (5,7-DHT), and compared with the time-course of changes in brain and spinal cord indolamine neurons. Following a substantial depletion of both amines in all CNS regions (telodiencephalon, brainstem and spinal cord) at 10 days after 150 mug 5,7-DHT, brain NA--but not 5-HT--levels recovered to near-normal values in brainstem and forebrain (35% below the age-matched controls) within 4 months. This was accompanied by a total restoration of the initially decreased capacity of the brain tissue to accumulate 3H-NA in vitro. Within 10 days after 5,7-DHT, there was a disappearance of NA terminals from many telencephalic, diencephalic and lower brain stem nuclei, from the cerebral and cerebellar cortices, and the grey matter of the spinal cord, concomitant with the appearance of numerous distorted, highly fluorescent swellings along the non-terminal axons of the major noradrenergic projection pathways. The recovery of the NA levels was paralleled by a re-appearance of fluorescent fibres, signifying an intense sprouting and regrowth of the drug-lesioned axons, which eventually re-innervated some of the previously denervated telodiencephalic regions. Except for a permanent loss of some surface-near perikarya in group A1 (the main source of the bulbospinal projections) there was no evidence of a retrograde degeneration of noradrenergic cell bodies in the rat CNS. The results are compatible with the idea that 5,7-DHT mainly causes a lesion of NA axons at a distance from the cell bodies, and this is followed by sprouting and regrowth of axons from the lisioned neurites, and formation of new terminal-like fibres in some previously denervated telodiencephalic regions. These findings indicate that chemical axotomy of central NA neurons induced by 5,7-DHT is--in contrast to that induced by 6-hydroxydopamine--followed by extensive axonal regeneration.     

Shift Work Disorder in a Random Population Sample – Prevalence and Comorbidities

Few studies have investigated the presence of shift work disorder (SWD) in the general community. We addressed many of the limitations in this literature and present new findings. SWD has been treated as an ‘all or none’ construct but we propose the need to consider the ‘severity’ of the disorder. Using random digit dialling, we randomly recruited 1163 participants. Participants completed an extensive battery of scales and questions concerning work, health and individual differences. Three questions based on the criteria from the International Classification for Sleep Disorders were used to categorise participants with SWD (n = 176). In addition, we asked participants whether SWD interfered with aspects of their life and high ratings were used to define severe shift work disorder (SSWD). The prevalence of SWD was 32.1% among night workers and 10.1% in day workers (p<.001). SSWD was present in 9.1% of night workers and 1.3% of day workers (p<.001). Adjusted logistic regression analyses found significant associations between SWD and night work (OR  = 3.35, CI 2.19-5.12), weekly work hours (OR  = 1.02, CI 1.00–1.04), short sleep (≤6 h; OR  = 2.93, CI 1.94–4.41), languidity (OR  = 1.11, CI 1.06–1.16) and resilience (OR  = 0.56, CI 0.43–0.81). Night work, short sleep, languidity, and hypertension were significantly associated with SSWD. Overall, participants with SSWD slept 0.80 h less than other participants (p<.001). Night work, short sleep and languidity were associated with both SWD and SSWD. Day workers with SWD symptoms reported significantly shorter sleep duration, higher levels of languidity and worked longer working hours compared to day workers without SWD.     

Family studies of hereditary hemochromatosis in Denmark and the Faroe Islands

Summary Pedigree studies were performed based on one Faroese and four Danish probands with overt idiopathic hemochromatosis (IH). The study consisted of HLA typing and determination of biochemical iron status indicators (serum transferrin saturation, serum ferritin). In total, 130 persons were evaluated. The screening identified 6 homozygous (h/h) subjects with preclinical IH, 46 heterozygous (h/n), and 8 normal (n/n) subjects, while 39 subjects were classified as normal or heterozygous (n/h?). One family demonstrated both a homozygous x heterozygous as well as a heterozygous x heterozygous mating. Recombination between the HLA region and IH locus occurred possibly in three subjects in three different families. The significance of detailed screening in families with probands with IH is discussed.     

Combined perfusion and percolation of embalmed animal bodies for removing formaldehyde

Excess formaldehyde was extracted from embalmed animal cadavers by vascular perfusion or combined perfusion and percolation with 20% ethanol. The perfusion was undertaken through a carotid artery and the percolation through the serous body cavities for 1-2 h. Nineteen goats were perfused once and one goat and three cows were perfused and percolated twice a day for 3 days. The extracted cadavers were stored in 20% ethanol or in a freezer at -20 degrees C. The mean value of the atmospheric concentration of formaldehyde after extraction was 0.27 +/- 0.05 mg/m3 for goats and 0.39 +/- 0.12 mg/m3 for cows.     

Photometric determination of glycogen in stained liver sections

Summary Sections of developing chicken liver stained for glycogen according to Best have been photometrically analysed. It is concluded that such photometric determinations may be performed with a high degree of reliability and reproducibility.There is a close direct proportionality between the optical density in Best-stained sections and the chemically determined concentration of bound glycogen.This study was supported in part by a grant from the Swedish Medical Research Council.     

The intranuclear movement of Balbiani ring premessenger ribonucleoprotein particles.

Specific premessenger ribonucleoprotein (pre-mRNP) particles, the Balbiani ring (BR) granules in the salivary glands of the dipteran Chironomus tentans, can be visualized in the electron microscope when they assemble on the genes, move through nucleoplasm, and bind to and translocate through the nuclear pores. As shown by BrUTP labeling and immunoelectron microscopy, newly synthesized BR RNP particles, released from the BR genes, appear early in all nucleoplasmic regions of the cell nucleus and they saturate the nucleoplasmic pool of BR particles after 2 h of labelling. It is concluded that within the nucleus the BR particles move randomly. Furthermore, estimates of minimum diffusion coefficients for the BR particles are compatible with the view that the particles diffuse freely in the interchromosomal space, although it is not excluded that the random movement could be slightly retarded. Once the particles get bound to the nuclear pore complexes, they seem committed to translocation through the nuclear pores.     

Demonstration of endocytosis vesicles by means of electron-microscopic histochemistry

Summary A phosphatase activity similar to that of the plasma membrane is demonstrated at the inside of the membrane, which delimits the lipid-containing lysosomes of chicken liver parenchymal cells. This is taken as a definite confirmation of their endocytotic origin.It should be possible to demonstrate endocytosis vesicles in other cells in this way. It is, however, pointed out, that cells with a weak plasma membrane activity may require particular attention to certain steps in the technical procedure.This study was supported in part by a grant from the Swedish Medical Research Council.     

Structural determinants of multimerization and dissociation in 2-Cys peroxiredoxin chaperone function

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