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At least 703 records · Page 39Linked to original sources
PubMed2003

Chemodenervation for facial dystonias and wrinkles.

PURPOSE OF REVIEW: Chemodenervation has evolved greatly over the past 30 years since botulinum toxin was first introduced as a therapeutic injection for managing strabismus. RECENT FINDINGS: Botulinum toxins are now accepted as a first-line treatment for patients suffering from spasms secondary to facial dystonias. These treatments are extremely effective and well tolerated by most patients. New agents including doxorubicin, Doxil, and ricin mab35 are being developed to create a longer-lasting treatment option for patients with facial dystonias. Recently the use of chemodenervation for managing facial wrinkles has expanded the use of these agents. The botulinum toxins have been found to be extremely efficacious in managing facial wrinkles, especially in the upper half of the face. The federal drug administration approved the use of Botox (Allergan, Irvine, CA) for glabellar furrows. Periocular crow's feet lines and horizontal forehead lines are also amenable to treatment with the botulinum toxins. Further uses including chemical browlift, as well as lower face and neck line treatments have also been described. SUMMARY: The use of the botulinum toxins has revolutionized the treatment of a broad array of diseases from benign essential blepharospasm to facial wrinkles.

Botulinum Toxins↗
PubMed2006

Acetabular component orientation in 834 total hip arthroplasties using a manual technique.

UNLABELLED: Acetabular component orientation during total hip arthroplasty affects dislocation, range of motion, polyethylene wear, pelvic osteolysis, and component migration. New total hip arthroplasty navigation systems have been introduced to avoid the errors reported after acetabular component orientation using a manual technique. We investigated acetabular component orientation in 834 consecutive primary total hip arthroplasties performed by one surgeon using a manual technique. We examined the relationship between dislocation and a defined safe range. Vertical tilt and planar anteversion were 44.4 +/- 6.5 and 17.9 +/- 6.3 (mean +/- standard deviation), respectively. The error of vertical tilt and planar anteversion were 5.2 +/- 3.9 and 5.3 +/- 4 (mean +/- standard deviation), respectively. Two hundred thirty-three of 834 hips (27.8 %) were outside the safe range. Logistic regression analysis showed that patients with Group IV class according to the classification system of Crowe et al and right hips had a greater risk of being outside the safe range. Navigation systems should be considered, especially in patients with highly dislocated hips. We found no relationship between risk of dislocation and the safe range. Factors other than acetabular component orientation also might affect dislocation. LEVEL OF EVIDENCE: Prognostic Study, Level IV (case series).

Acetabulum↗
PubMed2006

Transoral robotic surgery (TORS) for base of tongue neoplasms.

OBJECTIVE: To develop a minimally invasive surgical technique for the treatment of base of tongue neoplasms using the optical and technical advantages of robotic surgical instrumentation. STUDY DESIGN: Ten experimental procedures including tongue base exposure and dissections were performed on three cadavers and two mongrel dogs. Transoral robotic surgery (TORS) was then performed on three human patients with tongue base cancers in a prospective human trial. METHODS: Using the da Vinci Surgical Robot (Intuitive Surgical, Inc., Sunnyvale, CA), we performed a total of 10 base of tongue resections on edentulous and dentate cadavers as well as live mongrel dogs. In the cadaver models, exposure was evaluated using three different retractors, the Dingman, Crowe Davis, and FK retractors. The three human patients underwent TORS surgery of their tongue base cancers under an institutional review board approved prospective clinical trial. The ability to identify and preserve or resect key anatomic structures such as the glossopharyngeal, hypoglossal, and lingual nerves as well as techniques for identifying the lingual artery and achieving hemostasis were developed. RESULTS: The da Vinci Surgical Robot provided excellent visualization and enabled removal of the posterior one third to one half of the oral tongue in cadavers, dogs, and human patients. Among the three retractors evaluated, the FK retractor offered the greatest versatility and overall exposure for robotic instrument maneuverability. Complete resection to negative surgical margins with excellent hemostasis and no complications was achieved in the live patient surgeries. CONCLUSIONS: TORS provided excellent three-dimensional visualization and instrument access that allowed successful surgical resections from cadaver models to human patients. TORS is a novel and minimally invasive approach to tongue neoplasms that has significant advantages over classic open surgery or endoscopic transoral laser surgery.

Animals↗
PubMed2004

Update on botulinum toxin use in facial plastic and head and neck surgery.

PURPOSE OF REVIEW: The purpose of this review is to discuss current trends in the medicinal use of botulinum toxin in head and neck and facial plastic surgery. The basic science of botulinum toxin is presented along with a comparison of the subtypes currently available on the market. Site-specific applications of botulinum toxin in the head and neck region are presented. RECENT FINDINGS: The use of botulinum toxin continues to expand, both in volume and in number of applications. The main application of botulinum toxin in facial plastic surgery is in the effacement of dynamic or hyperkinetic facial lines. The granting of US Food and Drug Administration approval for the use of Botulinum Toxin type A in the treatment of glabella lines marks a major milestone for the more widespread usage of this product in cosmetic settings. Additional cosmetic applications include crow's feet, marionette lines, and platysma banding. Noncosmetic applications in the head and neck include dystonias (including torticollis), facial and generalized muscle spasms, migraine headaches, hyperhidrosis, spasmodic dysphonia, sialorrhea, gustatory sweating, and involuntary movement disorders. SUMMARY: The use of botulinum toxin in the treatment of hyperkinetic conditions and disorders of excessive salivation is well established and enjoys an excellent safety profile. The cosmetic use of botulinum toxin continues to expand. The chronic use of botulinum toxin specifically for cosmetic purposes is worthy of additional study.

Botulinum Toxins↗
PubMed2003

Pleomorphic liposarcoma of the uterus: case report and literature review.

A 62-year-old woman with a history of breast carcinoma being treated with tamoxifen presented with a rapidly enlarging pelvic mass. Imaging studies suggested a uterine leiomyoma with possible sarcomatous transformation. Laparotomy revealed a 15-cm, oval, well-circumscribed mass emanating from the posterior cervix and left uterosacral ligament. The tumor had a variegated fleshy, tan, myxoid, and necrotic sectioned surface. Microscopic examination revealed a variety of patterns and cell types characteristic of liposarcoma that included myxoid/round cell, storiform/pleomorphic, epithelioid, and spindle cell areas. Lipogenic areas exhibited a "crow's feet" vasculature and characteristic lipoblasts. The tumor cells were highly pleomorphic with numerous mitotic figures, some of them atypical. The tumor cells were immunoreactive for vimentin, estrogen receptors, and S-100. The tumor recurred 9 months postoperatively. Although a variety of uterine tumors have been associated with tamoxifen treatment, this appears to be the first example of tamoxifen-associated uterine liposarcoma.

Antineoplastic Agents, Hormonal↗
PubMed2004

Consensus recommendations on the use of botulinum toxin type a in facial aesthetics.

The use of botulinum toxin type A for facial enhancement is the most common cosmetic procedure currently undertaken in the United States. Overall clinical and study experience with botulinum toxin type A treatment for facial enhancement has confirmed that it is effective and safe in both the short and long term. Nevertheless, consistent guidelines representing the consensus of experts for aesthetic treatments of areas other than glabellar lines have not been published. Therefore, a panel of experts on the aesthetic uses of Botox Cosmetic (botulinum toxin type A; Allergan, Inc., Irvine, Calif.) was convened to develop consensus guidelines. This publication comprises the recommendations of this panel and provides guidelines on general issues, such as the importance of the aesthetic evaluation and individualization of treatment, reconstitution and handling of the botulinum toxin type A, procedural considerations, dosing and injection-site variables, and patient selection and counseling. In addition, specific considerations and recommendations are provided by treatment area, including glabellar lines, horizontal forehead lines, "crow's feet," "bunny lines" (downward radiating lines on the sides of nose), the perioral area, the dimpled chin, and platysmal bands. The review of each area encompasses the relevant anatomy, specifics on injection locations and techniques, starting doses (total and per injection point), the influence of other variables, such as gender, and assessment and retreatment issues. Factors unique to each area are presented, and the discussion of each treatment area concludes with a review of key elements that can increase the likelihood of a successful outcome. Summary tables are provided throughout.

Botulinum Toxins, Type A↗
PubMed2005

A prospective study of anti-aging topical therapies using a quantitative method of assessment.

BACKGROUND: In the treatment of photoaged skin, glycolic acid works by removing superficial portions of the epidermis and stimulating dermis regeneration. Vitamins A, C, and E should stimulate collagen production and antioxidants should prevent free radical damage and skin aging. However, the effectiveness of different therapies has often relied on subjective methods of assessment. Histologic analysis has seldom been used because of the drawback of permanent scarring. In the literature, the use of a quantitative method for the assessment of facial rejuvenation has been described: the silicone replica technique. The authors' aim was to promote and recommend the use of this technique and, in particular, to test the effect of glycolic acid and multivitamin- and antioxidant-based products on skin texture. METHODS: The authors performed a prospective, randomized, double-blind, controlled study on 30 women treated topically in the outer canthal region (crow's-feet area). Patients were divided into three groups (groups A, B, and C); each group consisted of five patients between the ages of 31 and 40 years and five patients between the ages of 41 and 50 years. Group A was treated by glycolic acid application, initially at home for 2 weeks, followed by a higher concentration administered in the office weekly for six applications. Group B was treated by topical application at home of a multivitamin product daily for 3 months. Group C was treated with a cream base (placebo) for 3 months and represented the control group. Skin areas under treatment were photographed and reproduced by the silicone replica technique at baseline and at the end of treatment. This technique reproduces exactly the skin's texture. Digital images were obtained from skin replicas and analyzed by specific software for different parameters: roughness, microsulcus number, and width. Pretreatment and posttreatment values were compared using the Wilcoxon signed-rank test. RESULTS: In group A, microsulcus number and width were statistically decreased, but roughness was not. In groups B and C, parameters were not statistically modified. CONCLUSIONS: The silicone replica technique allowed a quantitative analysis of results obtained with different topical therapies. In particular, it confirmed the efficacy of glycolic acid in skin rejuvenation.

Adult↗
PubMed2004

Evaluating the effects of ice application on the pain felt during botulinum toxin type-a injections: a prospective, randomized, single-blind controlled trial.

The pain felt during botulinum toxin type-A injections and the troubled and distressed treatment it induces is common and well known for the patient and the doctor applying the treatment. This problem is further intensified on the patients who have needle phobia. The effect of ice application on the treatment zone before botulinum toxin type-A treatment on the pain felt during injections is investigated. Totally, 24 patients who underwent botulinum toxin type-A treatment in upper face region for esthetic purposes are included in the study. Ice was applied 5 minutes before the injections on the right lateral orbital zones (crow's feet area) of the patients, whereas on their left sides, toxin was injected without applying any ice. All the drugs were diluted by normal saline; 5 U of active botulinum toxin type-A was used in each diziem (0.1 mL). Total injection number was determined both in right and left areas as 8. Visual analog scale (VAS) was used for pain intensity and evaluation. On the side where ice was applied, the treatment was completed in 1 session and lasted shorter when compared with that of the control side. However, the average VAS values defining the pain that the patients felt in their right and left sides were found as 1.1 and 5.9, respectively. The clinical findings obtained indicated that pain is significantly reduced on the side where ice is applied. The statistical significance of the test results were evaluated by Student's t test, and the difference between VAS values was found statistically significant (P = 0.000).

Adult↗
PubMed2003

Is hippocampal volume affected by specialization for food hoarding in birds?

The hypothesis that spatial-memory specialization affects the size of the hippocampus has become widely accepted among scientists. The hypothesis comes from studies on birds primarily in two families, the Paridae (tits, titmice and chickadees) and the Corvidae (crows, nutcrackers, jays, etc.). Many species in these families store food and rely on spatial memory to relocate the cached items. The hippocampus is a brain structure that is thought to be important for memory. Several studies report that hoarding species in these families possess larger hippocampi than non-hoarding relatives, and that species classified as large-scale hoarders have larger hippocampi than less specialized hoarders. We have investigated the largest dataset on hippocampus size and food-hoarding behaviour in these families so far but did not find a significant correlation between food-hoarding specialization and hippocampal volume. The occurrence of such an effect in earlier studies may depend on differences in the estimation of hippocampal volumes or difficulties in categorizing the degree of specialization for hoarding or both. To control for discrepancies in measurement methods we made our own estimates of hippocampal volumes in 16 individuals of four species that have been included in previous studies. Our estimates agreed closely with previous ones, suggesting that measurement methods are sufficiently consistent. Instead, the main reasons that previous studies have found an effect where we did not are difficulties in assessing the degree of hoarding specialization and the fact that smaller subsets of species were compared than in our study. Our results show that a correlation between food-hoarding specialization and hippocampal volume cannot be claimed on the basis of present data in these families.

Adaptation, Physiological↗
PubMed2001

Finite time singularities in a class of hydrodynamic models.

Models of inviscid incompressible fluid are considered, with the kinetic energy (i.e., the Lagrangian functional) taking the form L approximately integral k(alpha)/vk/2dk in 3D Fourier representation, where alpha is a constant, 0<alpha<1. Unlike the case alpha=0 (the usual Eulerian hydrodynamics), a finite value of alpha results in a finite energy for a singular, frozen-in vortex filament. This property allows us to study the dynamics of such filaments without the necessity of a regularization procedure for short length scales. The linear analysis of small symmetrical deviations from a stationary solution is performed for a pair of antiparallel vortex filaments and an analog of the Crow instability is found at small wave numbers. A local approximate Hamiltonian is obtained for the nonlinear long-scale dynamics of this system. Self-similar solutions of the corresponding equations are found analytically. They describe the formation of a finite time singularity, with all length scales decreasing like (t*-t)(1/(2-alpha)), where t* is the singularity time.

Journal Article↗
PubMed2002

Kerr-stabilized super-resonant modes in coupled-resonator optical waveguides.

We investigate the effects of the optical Kerr nonlinearity in a coupled-resonator optical waveguide (CROW). Under certain conditions, there exists a stationary spatial distribution of the field whose envelope does not change with time-a super-resonant mode. The analysis does not indicate the existence of traveling hyperbolic-secant solitons of the Schrödinger type.

Journal Article↗
PubMed2006

Quasispecies theory for multiple-peak fitness landscapes.

We use a path integral representation to solve the Eigen and Crow-Kimura molecular evolution models for the case of multiple fitness peaks with arbitrary fitness and degradation functions. In the general case, we find that the solution to these molecular evolution models can be written as the optimum of a fitness function, with constraints enforced by Lagrange multipliers and with a term accounting for the entropy of the spreading population in sequence space. The results for the Eigen model are applied to consider virus or cancer proliferation under the control of drugs or the immune system.

Biological Evolution↗
PubMed1982

Localization of a proton-translocating ATPase on sucrose gradients.

Ionophore-stimulated ATPase activity and ATP-dependent quinacrine quench were enriched in parallel when microsomal vesicles were prepared from corn (Crow Single Cross Hybrid WF9-Mo17) roots and collected on a cushion of 10% dextran. Activities were highest in the apical 1.5 centimeters of the roots. Vesicles collected on the dextran cushion also contained NADH cytochrome c reductase (enriched in the apical 0.5 cm of the root) and nucleoside diphosphatase (distributed throughout the first four cm). On continuous sucrose gradients, ATP-dependent proton transport and ionophore-stimulated ATPase activity coincided in a broad band extending from 1.08 to 1.15 grams per cubic centimeter with maximum activity at 1.10 to 1.12 grams per cubic centimeter. Large portions of the proton-translocating ATPase activity and ionophore-stimulated ATPase activity were clearly separable from mitochondrial membranes containing cytochrome c oxidase activity and azide-sensitive, pH 8.5 ATPase activity and from membranes bearing beta-glucan synthetase I and II. The vesicles coincided with a minor portion of the NADH-cytochrome c reductase and nucleoside diphosphatase activities. It is suggested that the vesicles are of tonoplast origin.

Journal Article↗
PubMed1982

Characterization of a proton-translocating ATPase in microsomal vesicles from corn roots.

Sealed microsomal vesicles were prepared from corn (Zea mays, Crow Single Cross Hybrid WF9-Mo17) roots by centrifugation of a 10,000 to 80,000g microsomal fraction onto a 10% dextran T-70 cushion. The Mg(2+)-ATPase activity of the sealed vesicles was stimulated by Cl(-) and NH(4) (+) and by ionophores and protonophores such as 2 micromolar gramicidin or 10 micromolar carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP). The ionophore-stimulated ATPase activity had a broad pH optimum with a maximum at pH 6.5. The ATPase was inhibited by NO(3) (-), was insensitive to K(+), and was not inhibited by 100 micromolar vanadate or by 1 millimolar azide.Quenching of quinacrine fluorescence was used to measure ATP-dependent acidification of the intravesicular volume. Quenching required Mg(2+), was stimulated by Cl(-), inhibited by NO(3) (-), was insensitive to monovalent cations, was unaffected by 200 micromolar vanadate, and was abolished by 2 micromolar gramicidin or 10 micromolar FCCP. Activity was highly specific for ATP. The ionophore-stimulated ATPase and ATP-dependent fluorescence quench both required a divalent cation (Mg(2+) >/= Mn(2+) > Co(2+)) and were inhibited by high concentrations of Ca(2+). The similarity of the ionophore-stimulated ATPase and quinacrine quench and the responses of the two to ions suggest that both represent the activity of the same ATP-dependent proton pump. The characteristics of the proton-translocating ATPase differed from those of the mitochondrial F(1)F(0)-ATPase and from those of the K(+)-stimulated ATPase of corn root plasma membranes, and resembled those of the tonoplast ATPase.

Journal Article↗
PubMed1983

Uptake and distribution of sodium and potassium by corn seedlings : I. Role of the mesocotyl in ;sodium exclusion'.

The distribution of sodium and potassium throughout corn (Zea mays L. [A632 x Crows 3640] x Oh 43) plants is not simply a matter of uptake by cortical cells and irreversible delivery to the xylem for upward transport. We show that sodium, but not potassium, accumulates in the mesocotyl of corn seedlings grown on NaCl medium. Upon transfer to NaCl-free medium, total sodium is reduced by export through the roots but remains at high levels within the mesocotyl. We report experiments which consider uptake from the xylem.Shoots excised at the seed were allowed to transpire solutions containing (22)Na and (42)K. Potassium uptake within the mesocotyl was very sensitive to concentration, increasing 27-fold between 1 and 10 millimolar. Sodium uptake was dependent upon the square root of the concentration suggesting active accumulation. At sodium concentrations below 1 millimolar, more than 80% of the sodium in the plant was retained in the mesocotyl. Both the uptake by and retention within the mesocotyl were dependent upon transpiration rate as well as concentration. We discuss the limitations of measuring uptake from a finite, depletable medium. The mesocotyl is a modified root with a cuticularized epidermis. We discuss the feasibility of using this ;plastic-coated root' as a model for root transport studies.

Journal Article↗
PubMed1984

Uronide Deposition Rates in the Primary Root of Zea mays.

The spatial distribution of the rate of deposition of uronic acids in the elongation zone of Zea mays L. Crow WF9 x Mo 17 was determined using the continuity equation with experimentally determined values for uronide density and growth velocity. In spatial terms, the uronide deposition rate has a maximum of 0.4 micrograms per millimeter per hour at s = 3.5 mm (i.e., at the location 3.5 mm from the root tip) and decreases to 0.1 mg mm(-1) h(-1) by s = 10 mm. In terms of a material tissue element, a tissue segment located initially from s = 2.0 to s = 2.1 mm has 0.14 mug of uronic acids and increases in both length and uronic acid content until it is 0.9 mm long and has 0.7 mug of uronide when its center is at s = 10 mm. Simulations of radioactive labeling experiments show that 15 min is the appropriate time scale for pulse determinations of deposition rate profiles in a rapidly growing corn root.

Journal Article↗
PubMed2004

Bipedal animals, and their differences from humans.

Humans, birds and (occasionally) apes walk bipedally. Humans, birds, many lizards and (at their highest speeds) cockroaches run bipedally. Kangaroos, some rodents and many birds hop bipedally, and jerboas and crows use a skipping gait. This paper deals only with walking and running bipeds. Chimpanzees walk with their knees bent and their backs sloping forward. Most birds walk and run with their backs and femurs sloping at small angles to the horizontal, and with their knees bent. These differences from humans make meaningful comparisons of stride length, duty factor, etc., difficult, even with the aid of dimensionless parameters that would take account of size differences, if dynamic similarity were preserved. Lizards and cockroaches use wide trackways. Humans exert a two-peaked pattern of force on the ground when walking, and an essentially single-peaked pattern when running. The patterns of force exerted by apes and birds are never as markedly two-peaked as in fast human walking. Comparisons with quadrupedal mammals of the same body mass show that human walking is relatively economical of metabolic energy, and human running is expensive. Bipedal locomotion is remarkably economical for wading birds, and expensive for geese and penguins.

Animals↗
PubMed1985

The anatomy and pathogenesis of wrinkles.

The anatomy of linear wrinkles ("crow's feet' and temporal frown lines), fine criss-cross wrinkles of the face and wrinkling of the general body surface of elderly persons, was studied by light and scanning electron microscopy. No histological features distinguished the various wrinkles from surrounding skin. It was concluded that the wrinkle is a configuration change, like the grooves worn into an old glove, without specific structural alterations at the histological level. As regards pathogenesis, the common setting was found to be deterioration of the elastic tissue network. The skin becomes looser, excessive, and loses the ability to snap back to its original state after being deformed.

Aged↗