A study of the long-term effect of malar fat repositioning in face lift surgery: short-term success but long-term failure

In 1990, the author reported on a series of 403 cases of deep plane face lifts, the first published technique describing the repositioning of the cheek fat, known as malar fat, in face lift surgery. This study examines the long-term results of 20 of the original series in an attempt to determine what areas of the rejuvenated face (specifically, the malar fat) showed long-term improvement. The results were judged by comparing the preoperative and long-term postoperative views in a half-and-half same-side hemiface photograph. The anatomy of the jawline (superficial musculoaponeurotic system [SMAS]), the nasolabial fold (malar fat), and the periorbital diameter were evaluated. The results confirmed that repositioning of the SMAS remained for longer than improvement in the nasolabial fold and that the vertical diameter of the periorbit did not change at all. The early results of malar fat repositioning shown at 1 to 2 years were successful, but the long-term results showed failure of the early improvement, manifested by recurrence of the nasolabial folds. There was, however, continuation of the improved results of the forehead lift and SMAS maneuvers of the original procedure. The conclusion is that only a direct excision will produce a permanent correction of the aging nasolabial fold.     

Interpopulational variation in recovery time from chill coma along a geographic gradient: a study in the common woodlouse, Porcellio laevis

Extreme temperatures restrict the performance of terrestrial arthropods and variations in low temperatures on a latitudinal scale influence physiological variables. Recovery time from chill coma is a measure of cold tolerance and it is a good index of climatic adaptation. We tested differences in recovery time of the common woodlouse (Porcellio laevis) exposed to different thermal conditions. Individuals were sampled from four different populations in Chile, spanning a latitudinal range of approximately 10 degrees . Significant differences were found in recovery time among experimental temperatures and among populations, but no interaction between these factors. The results of recovery time in P. laevis showed a positive increment with annual mean minimum temperature, indicating that there is geographical variation in recovery time. While body mass presented interpopulational variation, this variation was not associated with thermal variables or latitude. Overall, our results agree with previous studies in the sense that recovery time from chill coma decreases towards high latitudes, and it is independent of taxa, continent and hemisphere.     

Predictors of mortality of patients newly diagnosed with clinical type 2 diabetes: a 5-year follow up study

Background

At diabetes diagnosis major decisions about life-style changes and treatments are made based on characteristics measured shortly after diagnosis. The predictive value for mortality of these early characteristics is widely unknown. We examined the predictive value of patient characteristics measured shortly after diabetes diagnosis for 5-year all-cause and cardiovascular mortality with special reference to self-rated general health.

Methods

Data were from a population-based sample of 1,323 persons newly diagnosed with clinical diabetes and aged 40 years or over. Possible predictors of mortality were investigated in Cox regression models.

Results

Multivariately patients who rated their health less than excellent experienced increased all-cause and cardiovascular mortality. These end-points also increased with sedentary life-style, relatively young age at diagnosis and presence of cardiovascular disease (CVD) at diagnosis. Further predictors of all-cause mortality were male sex, low body mass index and cancer, while cardiovascular mortality increased with urinary albumin concentration.

Conclusions

We found that patients who rated their health as less than excellent had increased 5-year mortality, similar to that of patients with prevalent CVD, even when biochemical, clinical and life-style variables were controlled for. This finding could motivate doctors to discuss perceptions of health with newly diagnosed diabetic patients and be attentive to patients with suboptimal health ratings. Our findings also confirm that life-style changes and optimizing treatment are particularly relevant for relatively young and inactive patients and those who already have CVD or (micro)albuminuria at the time of diabetes diagnosis.     

A 30-year study of body temperature variations correlated with menstrual cycle,seasonality, and aging

Studies of human body temperature typically involve a small number of subjects or measurements taken over a relatively short timeframe. To enhance the size of the data-set and more reliably distinguish outlying values, oral temperature was measured each evening in a single female subject for 30 years. The results confirmed the well-known temperature variations during the menstrual cycle and the decreased temperature in older adults compared to young adults. The present study’s large data-set extended these results, revealing a gradual decline in temperature with advancing age during middle-age and a rapid decline in temperature during menopause. The results also revealed a convincing seasonal variation in body temperature that peaked in August and were lowest in February–March. A modest shift in body temperature was also related to daylight-saving time change. These results confirm and extend the findings of earlier studies, showing the relationship of body temperature to the menstrual cycle, seasonality, and aging.     

Wall stress of the cervical carotid artery in patients with carotid dissection: a case-control study

Spontaneous internal carotid artery (ICA) dissection (sICAD) results from an intimal tear located around the distal carotid sinus. The mechanisms causing the tear are unknown. This case-control study tested the hypotheses that head movements increase the wall stress in the cervical ICA and that the stress increase is greater in patients with sICAD than in controls. Five patients with unilateral, recanalized, left sICAD and five matched controls were investigated before and after maximal head rotation to the left and neck hyperextension after 45° head rotation to the left. The anatomy of the extracranial carotid arteries was assessed by magnetic resonance imaging and used to create finite element models of the right ICA. Wall stress increased after head movements. Increases above the 80th and 90th percentile were located at the intimal side of the artery wall from 7.4 mm below to 10 mm above the cranial edge of the carotid sinus, i.e., at the same location as histologically confirmed tears in patients with sICAD. Wall stress increase did not differ between patients and controls. The present findings suggest that wall stress increases at the intimal side of the artery wall surrounding the distal edge of the carotid bulb after head movements may be important for the development of carotid dissection. The lack of wall stress difference between the two groups indicates that the carotid arteries of patients with carotid dissection have either distinct functional or anatomical properties or endured unusually heavy wall stresses to initiate dissection.     

Modelling time-series of photosynthesis and comparisons with the fluorescence yield in Chlorella vulgaris: a study of adaptation, inhibition and recovery

Time-series of ¹⁴C uptake and fluorescence yield (i.e., thefluorescence enhancement after addition of the photosyntheticinhibitor DCMU) were measured in Chorella vulgaris at variouslight intensities. Adaptation and recovery processes after alterationof the light intensity were also studied. At a constant lightintensity, both the rate of ¹⁴C uptake and the fluorescenceyield decreased with time. Comparison of time-series data of¹⁴C uptake at different light intensities showed that this phenomenonconsisted of several processes (i.e., at low light intensitiessmall changes in uptake rates were mainly due to photoadaptation,while at higher light intensities relatively larger changesoccurred, as result of photoinhibition). Transfer of an algalsample to low light intensities after a period of exposure toinhibiting light intensities resulted in an exponential recoveryof the ¹⁴C uptake rate with time, coupled with an exponentialrecovery of the fluorescence yield. A mechanistic model is presented,which describes the algal ¹⁴C uptake rate as a function of timeand light intensity. The model includes adaptation, inhibitionand recovery. Six parameters, characterising the algal suspension,have to be estimated from the results of one P versus I curveand one time-series ¹⁴C uptake, which includes a period of recovery.Using these parameters the model can predict the time-courseof ¹⁴C uptake at every constant light intensity, as well aswhen the light intensity is changed during the experiment. Whenapplied to a culture of C. vulgaris, the theoretical valuesclosely approach the actual measurements. The resemblance betweenthe measured time-series of fluorescence yield and the rateof ¹⁴C uptake indicates, that the changes in the rate of ¹⁴Cuptake are due to changes in the photosynthetic apparatus, ratherthan to changes of diffusion of ¹⁴C into the cell.     

Stimulation of the autonomic nervous system in colorectal surgery: a study protocol for a randomized controlled trial

In this study we describe the sociodemographic characteristics of people participating in a clinical trial on the safety and immunogenicity of a H5N1 influenza vaccine and we identify the main motivations for joining it.     

Interaction of substrate uridyl 3'',5''-adenosine with ribonuclease A: a molecular dynamics study.

A wealth of information available from x-ray crystallographic structures of enzyme-ligand complexes makes it possible to study interactions at the molecular level. However, further investigation is needed when i) the binding of the natural substrate must be characterized, because ligands in the stable enzyme-ligand complexes are generally inhibitors or the analogs of substrate and transition state, and when ii) ligand binding is in part poorly characterized. We have investigated these aspects in the binding of substrate uridyl 3',5'-adenosine (UpA) to ribonuclease A (RNase A). Based on the systematically docked RNase A-UpA complex resulting from our previous study, we have undertaken a molecular dynamics simulation of the complex with solvent molecules. The molecular dynamics trajectories of this complex are analyzed to provide structural explanations for varied experimental observations on the ligand binding at the B2 subsite of ribonuclease A. The present study suggests that B2 subsite stabilization can be effected by different active site groups, depending on the substrate conformation. Thus when adenosine ribose pucker is O4'-endo, Gln69 and Glu111 form hydrogen-bonding contacts with adenine base, and when it is C2'-endo, Asn71 is the only amino acid residue in direct contact with this base. The latter observation is in support of previous mutagenesis and kinetics studies. Possible roles for the solvent molecules in the binding subsites are described. Furthermore, the substrate conformation is also examined along the simulation pathway to see if any conformer has the properties of a transition state. This study has also helped us to recognize that small but concerted changes in the conformation of the substrate can result in substrate geometry favorable for 2',3' cyclization. The identified geometry is suitable for intraligand proton transfer between 2'-hydroxyl and phosphate oxygen atom. The possibility of intraligand proton transfer as suggested previously and the mode of transfer before the formation of cyclic intermediate during transphosphorylation are discussed.     

Dynamics of yeast populations recovered from decaying leaves in a nonpolluted stream: a 2-year study on the effects of leaf litter type and decomposition time

Here we report on the results of a survey of the yeast populations occurring on submerged leaves (alder, eucalyptus and oak) in a natural mountain stream, during different phases of their decomposition and through two consecutive years. Leaf litter mass loss, total yeast counts, Shannon-Weiner index (H'), yeast community structure and physiologic abilities were analyzed to evaluate the dynamics of yeast communities during decay. Seventy-two yeast taxa were recorded, and in all litter types, species of basidiomycetous affinity predominated over ascomycetous ones. Discriminant analysis of presence/absence data (yeast species) showed significant differences both among substrate types (P<0.0026) and with decomposition time (P<0.0001). Carbon and nitrogen source utilization by yeast strains also varied with the substrate (P<0.0001) and decomposition time (P<0.0001). Further conclusions were that: (1) all litter types have in common ubiquitous yeast species, such as Cryptococcus albidus, Debaryomyces hansenii and Rhodotorula glutinis, among the common 20 yeast species; (2) only a few species were dominant, and most species were rare, being recorded once or twice throughout decomposition; and (3) the order of yeast appearance, and their substrate assimilation patterns, strongly suggest a succession phenomenon. Finally, explanations for the distribution patterns and variations in yeast communities are discussed.