8 results on '"Knoll BI"'
Search Results
2. Intracranial compartment volume changes in sagittal craniosynostosis patients: influence of comprehensive cranioplasty.
- Author
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Lee SS, Duncan CC, Knoll BI, and Persing JA
- Subjects
- Cephalometry methods, Child, Preschool, Craniosynostoses diagnostic imaging, Craniosynostoses surgery, Female, Follow-Up Studies, Humans, Imaging, Three-Dimensional, Infant, Male, Retrospective Studies, Skull growth & development, Skull surgery, Time Factors, Tomography, X-Ray Computed, Treatment Outcome, Craniosynostoses physiopathology, Craniotomy, Plastic Surgery Procedures methods, Skull diagnostic imaging
- Abstract
Background: A retrospective analysis of intracranial compartment volume changes in children with sagittal craniosynostosis was performed to clarify the therapeutic objectives of corrective surgery., Methods: Chart and computed tomographic review of 53 consecutive children with previously unoperated sagittal synostosis was performed, and preoperative and postoperative computed tomographic scans were examined and compared with 143 age- and gender-matched controls., Results: Preoperative mean intracranial compartment volume and mean brain tissue volume of each subgroup were age dependent. Brain volume was less in unoperated male sagittal synostosis patients (<6 months old) compared with controls (672.63 ml versus 716.14 ml). Brain tissue volume was approximately the same as controls for the 7- to 12-month and 12- to 30-month age groups. Long-term brain volume, however, again became less than controls with longer periods without treatment (31 to 60 months, 1050.6 versus 1291.51 ml, respectively). Intracranial compartment volume was less in unoperated male sagittal synostosis patients (<6 months old) compared with controls (706.6 ml versus 757.76 ml). Preoperative mean intracranial compartment volume, however, was greater than in controls in the 7- to 12-month (979.78 versus 970.34 ml) and 13- to 30-month age groups (1108.23 versus 1177.52 ml). Long term (31 to 60 months), however, intracranial compartment volume was less in untreated sagittal synostosis patients (1206.3 ml versus 1311.37 ml). Comparing day-1 postoperative sagittal synostosis patient data to age- and gender-matched controls to 1 year postoperatively, the operated patients develop an equivalent increase in skull growth compared with normals., Conclusions: Intracranial compartment volume is increased preoperatively in untreated sagittal synostosis patients older than 6 months. Intracranial compartment volume enlargement is largely attributable to an increase in brain volume. Comprehensive cranioplasty before 12 months of age increases intracranial compartment volume over normal growth.
- Published
- 2010
- Full Text
- View/download PDF
3. A congenital cleft of the alar rim.
- Author
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Patel A, Knoll BI, and Persing JA
- Subjects
- Female, Humans, Infant, Nose abnormalities, Nose surgery, Rhinoplasty methods
- Published
- 2009
- Full Text
- View/download PDF
4. Outcome analysis of combined lipoabdominoplasty versus conventional abdominoplasty.
- Author
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Heller JB, Teng E, Knoll BI, and Persing J
- Subjects
- Adult, Aged, Cohort Studies, Combined Modality Therapy, Female, Humans, Middle Aged, Outcome and Process Assessment, Health Care, Patient Satisfaction, Postoperative Complications etiology, Postoperative Complications surgery, Reoperation, Retrospective Studies, Abdominal Fat surgery, Cosmetic Techniques, Lipectomy
- Abstract
Background: Abdominoplasty and liposuction have traditionally been separate procedures. The authors performed a retrospective cohort study to evaluate the outcomes of a novel single-stage approach combining extensive lipoplasty with a modified transverse abdominoplasty., Methods: One hundred fourteen patients were evaluated for abdominal contouring. Patients were categorized into four groups: group I (n = 20) received abdominal liposuction only, group II (n = 33) traditional W-pattern incision line abdominoplasty, group III (n = 30) modified transverse incision abdominoplasty, and group IV (n = 31) combined procedure involving widely distributed abdominal liposuction accompanied by inverted V-pattern dissection abdominoplasty. Wound complications, patient satisfaction, and revision rates were compared statistically., Results: Group I (liposuction alone) experienced an overall complication rate of 5 percent; two patients were dissatisfied (10 percent) and underwent further revision with full abdominoplasties. Group II (traditional W-pattern abdominoplasty) had a complication rate of 42 percent, a dissatisfaction rate of 42 percent, and a revision rate of 39 percent. By comparison, group III (modified low transverse abdominoplasty) had a complication rate of 17 percent, a dissatisfaction rate of 37 percent, and a revision rate of 33 percent. Group IV (combined liposuction plus abdominoplasty) had significantly lower complication, dissatisfaction, and revision rates (9, 3, and 3 percent, respectively)., Conclusions: Modified transverse abdominoplasty combined with extensive liposuction and limited paramedian supraumbilical dissection produced fewer complications and less dissatisfaction than did traditional abdominoplasty. This may be attributable to a reduced tension midline closure in the suprapubic region, less lateral undermining in the upper abdomen, and greater preservation of intercostal artery blood flow to the flap.
- Published
- 2008
- Full Text
- View/download PDF
5. The influence of forehead, brow, and periorbital aesthetics on perceived expression in the youthful face.
- Author
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Knoll BI, Attkiss KJ, and Persing JA
- Subjects
- Adult, Emotions, Female, Humans, Male, Skin Aging physiology, Surveys and Questionnaires, Aging physiology, Esthetics, Eyebrows anatomy & histology, Eyelids anatomy & histology, Facial Expression, Forehead anatomy & histology, Rhytidoplasty methods, Visual Perception
- Abstract
Background: The purpose of this study was to characterize the relative influence of eyebrow position and shape, lid position, and facial rhytides on perceived facial expression as related to blepharoplasty, with a specific focus on the perception of tiredness., Methods: A standardized photograph of a youthful upper face was modified using digital imaging software to independently alter a number of variables: brow position/shape, upper/lower lid position, pretarsal show, and rhytides. Subjects (n = 20) were presented with 16 images and asked to quantify, on a scale from 0 to 5, the presence of each of seven expressions/emotions as follows: "surprise," "anger," "sadness," "disgust," "fear," "happiness," and "tiredness.", Results: Statistically significant values for tiredness were achieved by changes of increasing and decreasing the pretarsal skin crease, lowering the upper eyelid, and depressing the lateral brow. Happiness was perceived by elevation of the lower lid or the presence of crow's feet. Brow shape had a greater influence than absolute position on perceived expression. Elevation of the lateral brow was perceived as surprise, whereas depression of the medial brow and rhytides at the glabella were perceived as anger and disgust. Elevation of the medial brow elicited a minimal increase for sadness., Conclusions: This study showed that the perception of tiredness is most affected by the length of pretarsal lid height (e.g., ptosis). Surprisingly, simulating the skin resection of an upper blepharoplasty results in a paradoxical increase in the perception of tiredness as well. Modifications of brow contour elicit profound changes in perceived facial mood to a greater degree than absolute brow position.
- Published
- 2008
- Full Text
- View/download PDF
6. Prostaglandin E2 increases transforming growth factor-beta type III receptor expression through CCAAT enhancer-binding protein delta in osteoblasts.
- Author
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McCarthy TL, Pham TH, Knoll BI, and Centrella M
- Subjects
- Animals, CCAAT-Enhancer-Binding Protein-delta chemistry, Cyclic AMP-Dependent Protein Kinases metabolism, Gene Expression Regulation, Genes, Dominant, Inflammation, Models, Biological, Osteoblasts metabolism, Promoter Regions, Genetic, Protein Kinase C metabolism, Rats, Rats, Sprague-Dawley, Signal Transduction, CCAAT-Enhancer-Binding Protein-delta metabolism, Dinoprostone metabolism, Proteoglycans metabolism, Receptors, Transforming Growth Factor beta metabolism
- Abstract
Variations in individual TGF-beta receptors (TbetaRs) may modify TGF-beta activity and significantly alter its effects on connective tissue growth or repair. Differences in the amount of TbetaR type III (TbetaRIII) relative to signal transducing TbetaRI occur on bone cells during differentiation or in response to other growth regulators. Here we investigated prostaglandin (PG) E2, a potent effector during trauma, inflammation, or mechanical load, on TbetaR expression in primary osteoblast-enriched cultures. PGE2 rapidly increased TbetaRIII mRNA and protein expression and enhanced TbetaRIII gene promoter activity through a discrete region within 0.4 kb of the transcription start site. PGE2 alters osteoblast function through multiple signal-inducing pathways. In this regard, protein kinase A (PKA) activators, PGE1 and forskolin, also enhanced gene expression through the TbetaRIII gene promoter, whereas protein kinase C activators, PGF2alpha and phorbol myristate acetate, did not. The stimulatory effect of PGE2 on TbetaRIII promoter activity was suppressed by a dominant negative PKA-regulatory subunit, but not by dominant negative protein kinase C. PGE2 specifically increased nuclear factor CCAAT enhancer-binding protein delta (C/EBPdelta) binding to a half-binding site upstream of the basal TbetaRIII promoter region, and promoter activity was sensitive to C/EBPdelta overexpression and to dominant-negative C/EBPdelta competition. In parallel with their effect on TbetaRIII expression, activators of PKA decreased TGF-beta-induced activity. In summary, high levels of PGE2 that occur with inflammation or trauma may, through PKA-activated C/EBPdelta, preferentially increase TbetaRIII expression and in this way delay TGF-beta-dependent activation of osteoblasts during the early stabilization phase of bone repair.
- Published
- 2007
- Full Text
- View/download PDF
7. Strain-dependent control of transforming growth factor-beta function in osteoblasts in an in vitro model: biochemical events associated with distraction osteogenesis.
- Author
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Knoll BI, McCarthy TL, Centrella M, and Shin J
- Subjects
- Animals, Cell Division physiology, Cells, Cultured, Extracellular Matrix Proteins biosynthesis, Osteoblasts drug effects, Osteoblasts metabolism, Rats, Rats, Sprague-Dawley, Stress, Mechanical, Up-Regulation, Growth Substances physiology, Osteoblasts physiology, Osteogenesis physiology, Osteogenesis, Distraction, Proteins physiology
- Abstract
Background: Distraction osteogenesis is an important clinical method for increasing bone mass, but its effects on bone-forming cells are not well understood. In this study, the authors asked how the mechanical forces that occur during this procedure alter specific osteoblast activities such as matrix synthesis, the rate of cell replication, and enzyme activities. The authors further asked whether these changes relate to differences in the biochemical response of osteoblasts to transforming growth factor-beta (TGF-beta), a potent regulator of bone formation., Methods: Osteoblasts were plated on flexible, collagen-coated membranes. One group was unstrained, a second group experienced a single maximum strain load once every 6 hours to simulate intermittent force associated with a distraction protocol of four screw turns per day, and a third group was strained continuously for 24 hours. In the third group, some cell cultures were allowed to recover from strain before analysis. Subsequently, each group was treated with vehicle or TGF-beta at 12 pM (0.3 ng/ml) or 120 pM (3 ng/ml). Data were collected from a minimum of 15 replicate cell culture wells obtained from at least three separate primary culture preparations. Results were assessed with statistical software. Differences were considered significant with values of p < 0.05., Results: Both strain protocols increased basal osteoblast DNA synthesis but suppressed the relative stimulatory effect of TGF-beta on this event. However, neither intermittent nor continuous strain significantly altered collagen or noncollagen protein synthesis or the relative effect of TGF-beta on these processes in osteoblasts. Basal alkaline phosphatase activity, an intermediate marker of osteoblast differentiation and an early marker of matrix mineralization, decreased significantly in response to continuous strain or to TGF-beta treatment, and even more so in response to both conditions. In addition, TGF-beta binding to the type III TGF-beta receptor was increased in proportion to strain intensity., Conclusions: This study shows that cyclic strain can alter osteoblast activity in multiple ways and predicts that TGF-beta has different effects during the distraction process on osteoblasts and therefore on their ability to effect bone formation. They further indicate that mechanical load permits early aspects of osteoblast activation but delays in part later biochemical parameters associated with mineralization to allow new bone growth before consolidation.
- Published
- 2005
- Full Text
- View/download PDF
8. The bowstring canthal advancement: a new technique to correct the flattened supraorbital rim in unilateral coronal synostosis.
- Author
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Knoll BI, Shin J, and Persing JA
- Subjects
- Humans, Infant, Craniosynostoses complications, Orbit abnormalities, Orbit surgery, Plastic Surgery Procedures methods
- Abstract
Patients with unilateral coronal synostosis characteristically have a recessed and flattened supraorbital rim ipsilateral to the fused suture. Despite lateral canthal advancement procedures to correct these anomalies, patients often have a persistent flattened and recessed supraorbital rim after surgery. Current procedures address the pathologic features of the orbital rim only partially by advancing forward a deformed supraorbital rim without correcting the abnormal flattening of the normal rim curvature. The authors describe a technique modification of the supraorbital rim advancement procedure that addresses not only the lack of anterior positioning of it, but also its flattened contour: the bowstring canthal advancement.
- Published
- 2005
- Full Text
- View/download PDF
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