Catchment properties and the photosynthetic trait composition of freshwater plant communities.

Unlike in land plants, photosynthesis in many aquatic plants relies on bicarbonate in addition to carbon dioxide (CO2) to compensate for the low diffusivity and potential depletion of CO2 in water. Concentrations of bicarbonate and CO2 vary greatly with catchment geology. In this study, we investigate whether there is a link between these concentrations and the frequency of freshwater plants possessing the bicarbonate use trait. We show, globally, that the frequency of plant species with this trait increases with bicarbonate concentration. Regionally, however, the frequency of bicarbonate use is reduced at sites where the CO2 concentration is substantially above the air equilibrium, consistent with this trait being an adaptation to carbon limitation. Future anthropogenic changes of bicarbonate and CO2 concentrations may alter the species compositions of freshwater plant communities.

Crystalline structure, electronic and lattice-dynamics properties of NbTe2.

Layered-structure materials are currently relevant given their quasi-2D nature. Knowledge of their physical properties is currently of major interest. Niobium ditelluride possesses a monoclinic layered-structure with a distortion in the tellurium planes. This structural complexity has hindered the determination of its fundamental physical properties. In this work, NbTe2 crystals were used to elucidate its structural, compositional, electronic and vibrational properties. These findings have been compared with calculations based on density functional theory. The chemical composition and elemental distribution at the nanoscale were obtained through atom probe tomography. Ultraviolet photoelectron spectroscopy allowed the first determination of the work function of NbTe2. Its high value, 5.32 eV, and chemical stability allow foreseeing applications such as contact in optoelectronics. Raman spectra were obtained using different excitation laser lines: 488, 633, and 785 nm. The vibrational frequencies were in agreement with those determined through density functional theory. It was possible to detect a theoretically-predicted, low-frequency, low-intensity Raman active mode not previously observed. The dispersion curves and electronic band structure were calculated, along with their corresponding density of states. The electrical properties, as well as a pseudo-gap in the density of states around the Fermi energy are characteristics proper of a semi metal.

Herpesvirus replication compartments originate with single incoming viral genomes.

Previously we described a method to estimate the average number of virus genomes expressed in an infected cell. By analyzing the color spectrum of cells infected with a mixture of isogenic pseudorabies virus (PRV) recombinants expressing three fluorophores, we estimated that fewer than seven incoming genomes are expressed, replicated, and packaged into progeny per cell. In this report, we expand this work and describe experiments demonstrating the generality of the method, as well as providing more insight into herpesvirus replication. We used three isogenic PRV recombinants, each expressing a fluorescently tagged VP26 fusion protein (VP26 is a capsid protein) under the viral VP26 late promoter. We calculated a similar finite limit on the number of expressed viral genomes, indicating that this method is independent of the promoter used to transcribe the fluorophore genes, the time of expression of the fluorophore (early versus late), and the insertion site of the fluorophore gene in the PRV genome (UL versus US). Importantly, these VP26 fusion proteins are distributed equally in punctate virion assembly structures in each nucleus, which improves the signal-to-noise ratio when determining the color spectrum of each cell. To understand how the small number of genomes are distributed among the replication compartments, we used a two-color fluorescent in situ hybridization assay. Most viral replication compartments in the nucleus occupy unique nuclear territories, implying that they arose from single genomes. Our experiments suggest a correlation between the small number of expressed viral genomes and the limited number of replication compartments.

Cavernous hemangioma of the spinal cord - conservative or operative management?

Once believed to be extremely uncommon, due to magnetic resonance imaging cavernous hemangiomas of the spinal cord are detected with increasing frequency. Management of both symptomatic and asymptomatic intramedullary cavernous hamangiomas is therefore of growing importance. However, experience with treatment and follow-up is very limited. In particular, patients with multiple central nervous system cavernous hemangiomas represent a therapeutical dilemma. We present a patient with a ruptured intramedullary and multiple cerebral cavernous hemangiomas and a survey of current knowledge of epidemiology, pathophysiology and treatment options. We conclude that the benefit of operative treatment possibly decreases with the number of clinically silent vascular malformations.

Arabidopsis map kinase 4 negatively regulates systemic acquired resistance.

Transposon inactivation of Arabidopsis MAP kinase 4 produced the mpk4 mutant exhibiting constitutive systemic acquired resistance (SAR) including elevated salicylic acid (SA) levels, increased resistance to virulent pathogens, and constitutive pathogenesis-related gene expression shown by Northern and microarray hybridizations. MPK4 kinase activity is required to repress SAR, as an inactive MPK4 form failed to complement mpk4. Analysis of mpk4 expressing the SA hydroxylase NahG and of mpk4/npr1 double mutants indicated that SAR expression in mpk4 is dependent upon elevated SA levels but is independent of NPR1. PDF1.2 and THI2.1 gene induction by jasmonate was blocked in mpk4 expressing NahG, suggesting that MPK4 is required for jasmonic acid-responsive gene expression.

[Obstructive sleep apnoea syndrome. Assessment of the costs of examination and treatment in a department for pulmonary medicine]. / Obstruktivt søvnapnøsyndrom. En vurdering af omkostningerne ved undersøgelse og behandling i lungemedicinsk regi.

Twenty-five patients suspected of having obstructive sleep apnoea syndrome (OSA) were examined in the medical department. Sixteen patients had OSA. The difference between the two groups are described. The socio-economical consequences of the disease are discussed. Five of the patients remitted because of weight loss. Seven patients were successfully treated with nasal airway positive pressure. This treatment is of great benefit for the patients as well as for the society, and is inexpensive.

Ondine's curse in listeria monocytogenes brain stem encephalitis.

A case of necrotizing brain stem encephalitis due to listeria monocytogenes is described in a 48-year-old man who had brain stem encephalitis of complicated course and with selective destruction of the vasomotoric and respiratory centers. He developed that very rare Ondine's curse syndrome, being only able to breathe when awake. The literature on Ondine's curse and brain stem encephalitis due to LM is reviewed. Brain stem encephalitis has a mortality near 100%. The only treatment for Ondine's curse is lifelong artificial ventilation.

The effect of L-Deprenyl on on-off phenomena in Parkinson's disease.

L-Deprenyl, a specific monoamine oxidase subtype B inhibitor, has been reported a valuable adjunct to conventional treatment of Parkinsonism. A double-blind cross-over controlled study was performed in 19 parkinsonian patients with on-off type problems. Five mg L-Deprenyl per day reduced the number of on-off episodes. Side effects such as hyperkinesias, vivid dreams, dizziness with diaphoresis were frequent. Severe side effects such as nightmares, postural hypotension, confusion, and dizziness with headaches necessitated discontinuation of the drug in 4 patients. L-Deprenyl was of limited value in this group of patients with longstanding Parkinsonism.

Autoantibodies against pituitary peptides in sera from patients with multiple sclerosis.

Autoantibodies against pituitary peptides were demonstrated in sera from multiple sclerosis (MS) patients. Ten patients with lupus erythematosus disseminatus (SLE) and 97 healthy blood donors served as controls. The sera were used as primary antibodies in the indirect immuno-enzyme cytochemical (IEC) method, with fixed, paraffin-embedded rat brains and rat and hog pituitaries as antigen substrates. Eleven of the 33 MS sera reacted with peptides in the neural lobe/hypothalamic nuclei or distal lobe. The MS had a significantly higher incidence of peptide antibodies than sera from controls (11/33 vs 9/97). The mean antibody titers were significantly different (1577 vs 333). Comparison with rabbit reference antibodies specific to each of the 6 distal lobe hormones showed that the 9 distal lobe-positive MS sera reacted with cells harboring peptides of the somatotropin family. The presence of peptide autoantibodies was not related to clinical status or medical treatment. No antibodies against pituitary peptides were found in the SLE sera. One of the 11 positive MS sera showed antibodies against gastric parietal cells. None of the 11 sera showed antibodies against muscle, mitochondria, thyroid, adrenal, or parotid antigens. We propose that in a proportion of patients with MS, these autoantibodies might be involved in the demyelinization process by interfering with the peptide/receptor interplay, thus placing MS as a disease in analogy with myasthenia gravis. Alternatively, these autoantibodies might be involved in the altered immunoregulation of MS or be secondary to the disease.

Regional cerebral blood flow in patients with chronic subdural hematomas.

Cerebral blood flow (CBF) was measured by the intra-arterial 133Xenon method in seven patients, aged 55 to 76 years, with chronic subdural hematomas. Before operation, CBF was reduced to an average of 31 ml/100g/min, range 24-38 ml/100g/min. One to 3 weeks after operation, when all had improved, CBF averaged 38 ml/100g/min, range 34-43 ml/100g/min. The reduction of CBF was probably secondary to a reduced metabolic demand. Clinical improvement continued for months after operation.