In this paper we present a new method for analysing molecular evolution in homologous genes based on a general stationary Markov process. The elaborate statistical analysis necessary to apply the method effectively has been performed using Monte Carlo techniques. We have applied our method to the silent third position of the codon of the five mitochondrial genes coding for identified proteins of four mammalian species (rat, mouse, cow and man). We found that the method applies satisfactorily to the three former species, while the last appears to be outside the scope of the present approach. The method allows one to calculate the evolutionarily effective silent substitution rate (vs) for mitochondrial genes, which in the species mentioned above is 1.4 X 10(-8) nucleotide substitutions per site per year. We have also determined the divergence time ratios between the couples mouse-cow/rat-mouse and rat-cow/rat-mouse. In both cases this value is approximately 1.4.

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Tumour growth is angiogenesis-dependent. We found a high correlation between the extent of bone marrow angiogenesis, evaluated as microvessel area, and the proliferating (S-phase) fraction of marrow plasma cells, evaluated as labelling index (LI), in patients with multiple myeloma (MM) and in those with monoclonal gammopathies of undetermined significance (MGUS). Angiogenesis itself was significantly associated with active as opposed to non-active MM and MGUS. The highest microvessel area accompanied rapidly progressive MM with the highest LI. When a cut-off value of 2% or greater of the microvessel area was used, most patients with active MM were classified correctly. The risk of active disease in patients with MM increased in parallel with the microvessel area. A causal relationship between plasma cell growth, activity phase in MM and marrow angiogenesis is suggested. Since angiogenesis proceeds in step with the enlargement of plasma cell tumours and the activity phase in MM, its measurement could be a useful prognostic marker in patients with plasma cell proliferative disorders.

BackgroundProlonged controlled mechanical ventilation depresses diaphragmatic efficiency. Assisted modes of ventilation should improve it. We assessed the impact of pressure support ventilation versus neurally adjusted ventilator assist on diaphragmatic efficiency.MethodPatients previously ventilated with controlled mechanical ventilation for 72 hours or more were randomized to be ventilated for 48 hours with pressure support ventilation (n =12) or neurally adjusted ventilatory assist (n = 13). Neuro-ventilatory efficiency (tidal volume/diaphragmatic electrical activity) and neuro-mechanical efficiency (pressure generated against the occluded airways/diaphragmatic electrical activity) were measured during three spontaneous breathing trials (0, 24 and 48 hours). Breathing pattern, diaphragmatic electrical activity and pressure time product of the diaphragm were assessed every 4 hours.ResultsIn patients randomized to neurally adjusted ventilator assist, neuro-ventilatory efficiency increased from 27 ± 19 ml/μV at baseline to 62 ± 30 ml/μV at 48 hours (p <0.0001) and neuro-mechanical efficiency increased from 1 ± 0.6 to 2.6 ± 1.1 cmH2O/μV (p = 0.033). In patients randomized to pressure support ventilation, these did not change. Electrical activity of the diaphragm, neural inspiratory time, pressure time product of the diaphragm and variability of the breathing pattern were significantly higher in patients ventilated with neurally adjusted ventilatory assist. The asynchrony index was 9.48 [6.38– 21.73] in patients ventilated with pressure support ventilation and 5.39 [3.78– 8.36] in patients ventilated with neurally adjusted ventilatory assist (p = 0.04).ConclusionAfter prolonged controlled mechanical ventilation, neurally adjusted ventilator assist improves diaphragm efficiency whereas pressure support ventilation does not.Trial registrationClinicalTrials.gov study registration: NCT0247317, 06/11/2015.

The clinical data of 309 patients with definite multiple sclerosis were recorded in the European data base for multiple sclerosis (EDMUS) to determine the prognostic significance of several demographic and clinical variables. An interview with closed questions structured according to standardised criteria of disease phases and courses was used to assess the clinical course. The reliability was evaluated by four trained neurologists in a sample of 33 patients with multiple sclerosis. Both the within and between rater agreement on data collection was fair to high for the historical variables (K = 0.33-1). Between rater agreement was more variable for the evaluation of 12 different EDMUS event categories (K = 0-3-0.95). The predictive model for the time to reach a secondary progression showed that an age at onset older than 25 (p = 0 006) and an event at onset followed by disability >i3 on the Kurtzke expanded disability status scale (EDSS; p = 0-004) were the most unfavourable clinical variables in 249 patients with relapsing remitting (180) or relapsing progressive (69) courses. In the 69 patients with relapsing progressive disease, the time to reach severe disability (EDSS > 6) was negatively influenced by a first interval between attacks shorter than one year, a number of bouts with EDSS >2 in the first two years of the dis-