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An ongoing goal of aesthetic surgery is a reduction in complications and an improvement in reproducibility and speed. Balloon dissector devices have been used in other areas of surgery to achieve these goals. This report presents early clinical experience using a balloon dissector to elevate the skin flap in facialplasty. The first step in the technique is the creation of a tunnel from a small preauricular incision toward the oral commissure using scissors dissection. The balloon device is inserted into this tunnel and inflated. Unrolling the device elevates the skin flap in the cheek and neck area. Retroauricular dissection and final adjustment of flap size and shape is completed sharply. Subsequent superficial musculoaponeurotic system flap development, skin redraping, and closure is performed in a conventional fashion after customary facialplasty incisions are made. Comparison of complications, postoperative drainage, and time required for dissection and for hemostasis was made between a balloon-dissected side and a conventionally dissected side in 10 patients undergoing facialplasty. Ten additional patients were treated with balloon dissection bilaterally. Patients ranged in age from 45 to 73 years. Mean balloon dissection time was 1.4 minutes (range, 0.75-4 minutes). This produced an even flap thickness in the correct plane with few if any bleeding points. Mean total dissection time on the balloon side was significantly shorter-13.6 minutes-compared with 27.8 minutes (p < 0.003) on the conventional side. Mean difference in time to hemostasis between conventional and balloon sides was 3.8 minutes (p < 0.001). Mean total postoperative drainage (all drains removed at 24 hours) was 13.8 cc on the balloon side and 18.8 cc on the conventional side (not significant, p=0.08). Less ecchymosis and swelling was observed on the balloon side compared with the scissors-dissected side. There were no skin losses, hematomas, infections, or nerve injuries on either side. Appearance of skin redraping was comparable on each side in all patients. Balloon dissection represents a promising alternative means of creating rapid, reproducible skin flap elevation in facialplasty, and is associated with a minimum of bleeding, ecchymosis, and swelling.  相似文献   
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Bipolar meiotic spindle formation without chromatin   总被引:1,自引:0,他引:1  
Establishing a bipolar spindle is an early event of mitosis or meiosis. In somatic cells, the bipolarity of the spindle is predetermined by the presence of two centrosomes in prophase. Interactions between the microtubules nucleated by centrosomes and the chromosomal kinetochores enable the formation of the spindle. Non-specific chromatin is sufficient, however, to promote spindle assembly in Xenopus cell-free extracts that contain centrosomes [1,2]. The mouse oocyte represents an excellent model system in which to study the mechanism of meiotic spindle formation because of its size, transparency and slow development. These cells have no centrioles, and their multiple microtubule-organizing centers (MTOCs) are composed of foci of pericentriolar material [3,4]. The bipolarity of the meiotic spindle emerges from the reorganization of these randomly distributed MTOCs [4]. Regardless of the mechanisms involved in this reorganization, the chromosomes seem to have a major role during spindle formation in promoting microtubule polymerization and directing the appropriate rearrangement of MTOCs to form the two poles [5]. Here, we examined spindle formation in chromosome-free mouse oocyte fragments. We found that a bipolar spindle can form in vivo in the absence of any chromatin due to the establishment of interactions between microtubule asters that are progressively stabilized by an increase in the number of microtubules involved, demonstrating that spindle formation is an intrinsic property of the microtubule network.  相似文献   
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The effects of traditional risk factors on low birth weight were examined, using logistic regression analyses and adjusting for interactions between multiple factors. Data for 11,936 births were obtained from a state birth cohort file. The effect for maternal ethnicity was dependent on education and marital status; the effect of marital status was dependent on ethnicity, medical risk, and level of prenatal care; and the effect of prenatal care was dependent on marital status. Results suggest that examining only main effects and ignoring interactions can produce overgeneralized conclusions about the influence of individual risk factors on low birth weight.  相似文献   
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Cytokines and insulin-like growth factors (IGFs) are involved in the induction and/or perpetuation of inflammatory bowel disease. The effect of fasting on inflammatory bowel disease was studied in a mouse experimental model of acute colitis caused by adding dextran sulfate sodium (DSS) to drinking water. Animals were either fed ad libitum or fasted (water only) for 2 days before death. Inflammation and tissue damage, measured as a colitis activity score, were markedly reduced in fasted (2.4 +/- 0.1) compared to fed (5.3 +/- 0.1) DSS animals (P < 0.0001). Colon interleukin-1 beta (IL-1 beta), IGF-I, and tumor necrosis factor-alpha messenger RNAs (mRNAs) were quantified by Northern blot hybridization and expressed as a percentage of mRNA abundance in fed controls. In DSS mice, IL-1 beta mRNA was elevated in the fed group (954 +/- 155%; P < 0.001), but was suppressed in fasted animals (71.1 +/- 11%). IGF-I mRNA also was elevated in fed DSS mice (421 +/- 71%; P < 0.01). This increase was attenuated in fasted DSS mice (202 +/- 17%; P < 0.01 compared to fed DSS mice). Tumor necrosis factor-alpha mRNA was increased in fed DSS mice (162 +/- 15%; P < 0.01), but was not significantly lower in fasted animals. By in situ hybridization, IL-1 beta mRNA was localized to the lamina propria of colonic mucosa in fed DSS animals, but was not detectable in other groups. We conclude that fasting has a protective effect on the progression of acute DSS, induced colitis. This is associated with decreased expression of IL-1 beta and IGF-I mRNAs in the colon.  相似文献   
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OBJECTIVE: To determine the overall effect of paraplegia and pressure sores on resting metabolic rate. DESIGN: Unblinded, case-control study using a convenience sample. SETTING: Hospital primary care setting. PATIENTS: Fourteen individuals with paraplegia and pressure sores (PS-Para), 24 with paraplegia in good health (NPS-Para), and 23 non-spinal cord injury (SCI) controls. MAIN OUTCOME MEASURES: The planned outcome measures consisted of resting metabolic rate, percent of predicted resting metabolic rate, resting metabolic rate per kilogram body weight, and resting metabolic rate per meter squared body surface area. Post hoc analyses were used to identify the effect of completeness of lesion, smoking, and pressure sores on percent of predicted resting metabolic rate and resting metabolic rate per kilogram body weight. RESULTS: Percent of predicted resting metabolic rate and resting metabolic rate per kilogram body weight were significantly higher in the PS-Para group than in the NPS-Para or control groups (115% +/- 4% vs 100% +/- 2% or 107% +/- 2%, p < .05) and (25.9 +/- 1.2 vs 21.4 +/- 0.6 or 22.5 +/- 0.4 kcal/kg, p < .05, respectively). The resting metabolic rate per meter squared body surface area was significantly higher in the PS-Para group than in NPS-Para group (973 +/- 39 vs 874 +/- 20kcal/m2, p < .05). In the PS-Para group, current smokers had significantly higher resting metabolic rate per kilogram body weight than nonsmokers (27.3 +/- 1.7 vs 24.0 +/- 1.4kcal/kg, p < .01). Controlling for the effects of smoking in a multiple regression model, those in the PS-Para group had significantly (p < .001) greater percent of predicted resting metabolic rate and resting metabolic rate per kilogram body weight than those in the NPS-Para group. CONCLUSIONS: These findings indicate that individuals with SCI may have a decreased percent of predicted resting metabolic rate and those with pressure sores may have a hypermetabolic state. This hypermetabolic state is significantly higher than that resulting from smoking. Because ordinary prediction equations for energy expenditure may not be accurate when applied to subjects with paraplegia and pressure sores, quantification of energy needs by indirect calorimetry is recommended.  相似文献   
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