Resting energy expenditure and gut microbiota in obese and normal weight subjects.

OBJECTIVES: It is suggested that gut microbiota play a role in the pathogenesis of obesity enhancing energy utilization from digested food. The influence of gut microbiota on resting energy expenditure (REE) has not been evaluated yet. AIM: The aim of the study is to assess the composition on gut microbiota and its association with REE in obese and normal weight subjects. SUBJECTS AND METHODS: REE measurement and semi-quantitative analysis of gut microbiota composition in aerobic and anaerobic conditions were performed in 50 obese and 30 normal weight subjects without concomitant diseases. RESULTS: A count of bacterial colony was greater in obese than in normal weight subjects. However, the proportion of Bacteroides spp. and Firmicutes was similar in both study groups. A positive correlation between REE (kcal/d) and total bacterial count (r = 0.26, p < 0.05), as well as between REE and the percentage of Firmicutes (r = -0.24, p < 0.05) was found. The multiple regression analysis did not prove an independent impact of total bacterial as well as Bacteroides spp. and Firmicutes counts on REE. CONCLUSIONS: The composition of gut microbiota is not associated with the level of resting energy expenditure. The proportion of Bacteroides and Firmicutes in gut microbiota is not related to body mass.

Evaporation of freely suspended single droplets: experimental, theoretical and computational simulations.

Evaporation is ubiquitous in nature. This process influences the climate, the formation of clouds, transpiration in plants, the survival of arctic organisms, the efficiency of car engines, the structure of dried materials and many other phenomena. Recent experiments discovered two novel mechanisms accompanying evaporation: temperature discontinuity at the liquid-vapour interface during evaporation and equilibration of pressures in the whole system during evaporation. None of these effects has been predicted previously by existing theories despite the fact that after 130 years of investigation the theory of evaporation was believed to be mature. These two effects call for reanalysis of existing experimental data and such is the goal of this review. In this article we analyse the experimental and the computational simulation data on the droplet evaporation of several different systems: water into its own vapour, water into the air, diethylene glycol into nitrogen and argon into its own vapour. We show that the temperature discontinuity at the liquid-vapour interface discovered by Fang and Ward (1999 Phys. Rev. E 59 417-28) is a rule rather than an exception. We show in computer simulations for a single-component system (argon) that this discontinuity is due to the constraint of momentum/pressure equilibrium during evaporation. For high vapour pressure the temperature is continuous across the liquid-vapour interface, while for small vapour pressures the temperature is discontinuous. The temperature jump at the interface is inversely proportional to the vapour density close to the interface. We have also found that all analysed data are described by the following equation: da/dt = P(1)/(a + P(2)), where a is the radius of the evaporating droplet, t is time and P(1) and P(2) are two parameters. P(1) = -λΔT/(q(eff)ρ(L)), where λ is the thermal conductivity coefficient in the vapour at the interface, ΔT is the temperature difference between the liquid droplet and the vapour far from the interface, q(eff) is the enthalpy of evaporation per unit mass and ρ(L) is the liquid density. The P(2) parameter is the kinetic correction proportional to the evaporation coefficient. P(2) = 0 only in the absence of temperature discontinuity at the interface. We discuss various models and problems in the determination of the evaporation coefficient and discuss evaporation scenarios in the case of single- and multi-component systems.

Temperature dependence of the evaporation coefficient of water in air and nitrogen under atmospheric pressure: study in water droplets.

The evaporation coefficients of water in air and nitrogen were found as a function of temperature by studying the evaporation of a pure water droplet. The droplet was levitated in an electrodynamic trap placed in a climatic chamber maintaining atmospheric pressure. Droplet radius evolution and evaporation dynamics were studied with high precision by analyzing the angle-resolved light scattering Mie interference patterns. A model of quasi-stationary droplet evolution accounting for the kinetic effects near the droplet surface was applied. In particular, the effect of thermal effusion (a short-range analogue of thermal diffusion) was discussed and accounted for. The evaporation coefficient alpha in air and in nitrogen were found to be equal. The alpha was found to decrease from approximately 0.18 to approximately 0.13 for the temperature range from 273.1 to 293.1 K and follow the trend given by the Arrhenius formula. The agreement with condensation coefficient values obtained with an essentially different method by Li et al. [Li, Y.; Davidovits, P.; Shi, Q.; Jayne, J.; Kolb, C.; Worsnop, D. J. Phys. Chem. A. 2001, 105, 10627] was found to be excellent. The comparison of experimental conditions used in both methods revealed no dependence of the evaporation/condensation coefficient on the droplet charge nor the ambient gas pressure within the experimental parameters range. The average value of the thermal accommodation coefficient over the same temperature range was found to be 1 +/- 0.05.

[Bacterial flora in pharyngitis and tonsillitis]. / Flora bakteryjna w zapaleniu gardla i migdalków.

The aim of the study was a microbiological analysis of pharyngeal swabs obtained from 158 patients with the diagnosis of pharyngitis and purulent exudates from the tonsillar crypts of 10 patients treated for chronic purulent tonsillitis. Beta haemolytic streptococci groups A, B, C and G were isolated from 30% of the patients. The most frequently isolated were Streptococcus pyogenes--12% of patients and Streptococcus group C--10.7%. Other streptococci were isolated less frequently: Streptococcus group B--44%, group G--2.5%. The majority of isolated bacteria belonged to potential pathogenic flora (70% patients). Staphylococcus aureus (37%) and Haemophilus spp. (36%) were isolated most frequently. Other bacteria were isolated in the following sequence: Moraxella catarrhalis--22%, Streptococcus pneumoniae--17% and Gram-negative rods from the Enterobacteriaceae family--6%. One case of Plaut-Vincent tonsillitis was diagnosed. Aerobic and anaerobic bacteria were isolated from purulent exudates from the tonsillar crypts of 10 patients treated for chronic purulent tonsillitis. The isolated anaerobic bacteria belonged to genus of Prevotella, Fusobacterium, Peptostreptococcus and Gemella.

[Bacterial flora in chronic inner ear infections in adults]. / Flora bakteryjna w przewleklym zapaleniu ucha srodkowego u doroslych.

The aim of the study was to analyse microbiologically middle ear exudate obtained from 56 patients, aged 17 to 83 years, treated for chronic otitis media. Aerobic bacteria only were found 49 patients (87,5%). Mixed aerobic and anaerobic isolates were recovered from 7 patients (12,5%). The most common bacteria isolated from the middle ear exudate, in descending order frequency, were Staphylococcus aureus (45%), Pseudomonas aeruginosa (34%), Proteus mirabilis (16%) and Prevotella melaninogenica (9%). Other organisms were isolated less frequently. In 34 patients only one isolate was recovered, in 22 patients the isolated bacteria coexisted with other microorganisms.

[Treatment with neomycin and Na2EDTA for skin infections in rabbits caused by Staphylococcus aureus]. / Leczenie neomycyna i Na2EDTA doswiadczalnych zakazen skóry królika gronkowcem zlocistym.

The rabbits were infected intradermally with a strain of S. aureus resistant to neomycin. They were treated with neomycin, Na2EDTA and by combination of these substances, which were applied as a cream with differing concentrations of these factors. Simultaneous application of neomycin and Na2EDTA for treatment of experimental staphylococcal infections caused in rabbits with a strain resistant to neomycin, resulted in acceleration of healing of pustular changes, when compared with results obtained in animals treated with these substances alone.