The principle of regulation in biology--from bone to eating behavior.

Cell physiology and molecular biology typically follow a reductionistic approach in science. In the last decade, molecular principles and pathogenetic factors involved in the development of many diseases have been successfully discovered. Therefore, early biological concepts based on systemic and cybernetic thoughts have been largely overshadowed by these more recent molecular and pathogenetic factors. This review highlights discoveries on bone development and hypothalamic controlled feeding and eating behavior with a cybernetic and systemic perspective. Interestingly, ancient ideas on bone development and hypothalamic function are still reasonable considerations to embed new molecular discoveries into a systemic concept of principles organizing nature.     

Pre-eclampsia is associated with sleep-disordered breathing and endothelial dysfunction.

Pre-eclamptic toxaemia (PET) may be associated with both endothelial dysfunction (ED) and sleep-disordered breathing (SDB). It was hypothesised that females with PET would demonstrate both SDB and ED, and that a correlation between these two would suggest a potential causative association. A total of 17 females with PET and 25 matched females with uncomplicated pregnancy were studied. They underwent a nocturnal ambulatory sleep study (using Watch_PAT100) and noninvasive evaluation of endothelial function utilising the reactive hyperaemia test (using Endo_PAT 2000). A higher ratio of post- to pre-occlusion pulse-wave amplitude (endothelial function index (EFI)) indicated better endothelial function. Females with PET had a significantly higher respiratory disturbance index (RDI) and lower EFI than controls (18.4+/-8.4 versus 8.3+/-1.3.h(-1), and 1.5+/-0.1 versus 1.8+/-0.1, respectively). Blood pressure significantly correlated with RDI and with EFI. EFI tended to correlate with RDI. In conclusion, these results suggest that both sleep-disordered breathing and endothelial dysfunction are more likely to occur in females with pre-eclamptic toxaemia than in females with uncomplicated pregnancies. The current authors speculate that respiratory disturbances contribute to the functional abnormality of the blood vessels seen in females with pre-eclamptic toxaemia, although causality cannot be determined based on this study.     

Computed tomography and pulmonary function abnormalities in sickle cell disease.

The aim of this study was to determine whether patients with sickle cell disease (SCD) in steady state had pulmonary abnormalities seen on high-resolution computed tomography (HRCT) and whether any abnormalities correlated with contemporaneously diagnosed lung function abnormalities. A subsidiary question was whether the results of a noninvasive measure of haemolysis (end-tidal carbon monoxide (ETCO) levels) correlated with pulmonary function abnormalities. Thirty three patients with SCD, median (range) age 36 yrs (17-67 yrs) were examined. The degree of lobar volume loss and ground-glass opacification and prominence of central vessels on HRCT were quantitatively assessed. Pulmonary function was assessed by measurements of lung volumes, spirometry, gas transfer and oxygen saturation. ETCO levels were measured using an end-tidal CO monitor. Forced expiratory volume in one second (FEV1), forced vital capacity and total lung capacity significantly correlated with HRCT findings, particularly lobar volume loss. ETCO levels significantly negatively correlated with FEV1, vital capacity measured using a plethysmograph, specific airway conductance and arterial oxygen saturation measured by pulse oxymetry. In conclusion, the present results suggest that high-resolution computed tomography noninvasive assessment of haemolysis might be useful to identify sickle cell disease patients with respiratory function impairment.     

Comparison of asthma treatment given in addition to inhaled corticosteroids on airway inflammation and responsiveness.

There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation.     

NT-proBNP reflects right ventricular structure and function in pulmonary hypertension.

The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function.     

Pharmacokinetics of Moxifloxacin in Rabbits After Intravenous,Subcutaneous and a Long‐acting Poloxamer 407 Gel Formulation Administration

The pharmacokinetics (PK) of moxifloxacin in healthy white New Zealand rabbits was studied following intravenous (IV) and subcutaneous (SC) administration routes as well as a SC long‐acting poloxamer 407 gel formulation (SC‐P407). Moxifloxacin concentrations were determined by high‐performance liquid chromatography assay with fluorescence detection. Mean half‐life for IV, SC and SC‐P407 routes was 2.15, 5.41 and 11.09 h. Clearance value after IV dosing was 0.78 l/kg/h. After SC administration, the mean absolute bioavailability was 117% and the C_max was 1.61 ± 0.49 mg/l. After SC‐P407 administration, the bioavailability was 44% and the C_max 1.83 was ±0.62 mg/l. No adverse effects were observed in any of the rabbits following IV, SC and SC‐P407 administration of moxifloxacin. Minimal inhibitory concentrations of moxifloxacin against different strains of Staphylococcus aureus from different european countries were used to compute the main pharmacodynamic (PD) surrogate markers of efficacy. The high tolerability of this SC‐P407 formulation and the favourable PK behaviour such as the long half‐life, acceptable bioavailability and excellent PK–PD ratios achieved indicate that it is likely to be effective in rabbits.     

A presenilin 1 mutation (L420R) in a family with early onset Alzheimer disease,seizures and cotton wool plaques,but not spastic paraparesis

Over 100 mutations in the presenilin‐1 gene (PSEN1) have been shown to result in familial early onset Alzheimer disease (EOAD), but only a relatively few give rise to plaques with an appearance like cotton wool (CWP) and/or spastic paraparesis (SP). A family with EOAD, seizures and CWP was investigated by neuropathological study and DNA sequencing of the PSEN1 gene. Aβ was identified in leptomeningeal vessels and in cerebral plaques. A single point mutation, p.L420R (g.1508T > G) that gives rise to a missense mutation in the eighth transmembrane (TM8) domain of PS1 was identified in two affected members of the family. p.L420R (g.1508T > G) is the mutation responsible for EOAD, seizures and CWP without SP in this family.