A dense ring of the trans-Neptunian object Quaoar outside its Roche limit.

Planetary rings are observed not only around giant planets1, but also around small bodies such as the Centaur Chariklo2 and the dwarf planet Haumea3. Up to now, all known dense rings were located close enough to their parent bodies, being inside the Roche limit, where tidal forces prevent material with reasonable densities from aggregating into a satellite. Here we report observations of an inhomogeneous ring around the trans-Neptunian body (50000) Quaoar. This trans-Neptunian object has an estimated radius4 of 555 km and possesses a roughly 80-km satellite5 (Weywot) that orbits at 24 Quaoar radii6,7. The detected ring orbits at 7.4 radii from the central body, which is well outside Quaoar's classical Roche limit, thus indicating that this limit does not always determine where ring material can survive. Our local collisional simulations show that elastic collisions, based on laboratory experiments8, can maintain a ring far away from the body. Moreover, Quaoar's ring orbits close to the 1/3 spin-orbit resonance9 with Quaoar, a property shared by Chariklo's2,10,11 and Haumea's3 rings, suggesting that this resonance plays a key role in ring confinement for small bodies.

Endogenetic craters interpreted from crater counts on the inner wall of copernicus.

Collapse craters formed in terrestrial basalt flows exhibit size-frequency distributions that are similar to distributions for craters located in terraces in the inner wall of the lunar crater Copernicus. These distributions and surface morphology suggest that the interior terraces are basalt lava flows containing collapse craters as well as impact craters.

Luna 9 photographs: evidence for a fragmental surface layer.

The morphological features of the lunar surface photographed by Luna 9 indicate a surficial layer of weakly cohesive to noncohesive frag mental material. Most of this material is finer than a centimeter and probably finer than a few millimeters, although objects of centimeter size and larger are plentiful.

Surveyor v: discussion of chemical analysis.

Material of basaltic composition at the Surveyor V landing site implies that differentiation has occurred in the moon, probably due to internal sources of heat. The results are consistent with the hypothesis that extensive volcanic flows have been responsible for flooding and filling the mare basins. The processes and products of lunar magmatic activity are apparently similar to those of the earth.

Mariner 10 pictures of mercury: first results.

Mercury has a heavily cratered surface cotntaining basins up to at least 1300 kilometers diameter flooded with mare-like material. Many features are closely similar to those on the moon, but significant structural differences exist. Major chemical differentiation before termination of accretion is implied.

Venus: atmospheric motion and structure from mariner 10 pictures.

The Mariner 10 television camieras imaged the planet Venus in the visible and near ultraviolet for a period of 8 days at resolutions ranging from 100 meters to 130 kilometers. Tle general pattern of the atmospheric circulation in the upper tropospheric/lower stratospheric region is displayed in the pictures. Atmospheric flow is symmetrical between north and south hemispheres. The equatorial motions are zonal (east-west) at approxiimnately 100 meters per second, consistent with the previously inferred 4-day retrograde rotation. Angular velocity increases with latitude. The subsolar region, and the region downwind from it, show evidence of large-scale convection that persists in spite of the main zonal motion. Dynamical interaction between the zonal motion and the relatively stationary region of convection is evidenced by bowlike waves.

Mercury's Surface: Preliminary Description and Interpretation from Mariner 10 Pictures.

The surface morphology and optical properties of Mercury resemble those of the moon in remarkable detail and record a very similar sequence of events. Chemical and mineralogical similarity of the outer layers of Mercury and the moon is implied; Mercury is probably a differentiated planet with a large iron-rich core. Differentiation is inferred to have occurred very early. No evidence of atmospheric modification of landforms has been found. Large-scale scarps and ridges unlike lunar or martian features may reflect a unique period of planetary compression near the end of heavy bombardment by small planetesimals.

Tongue necrosis after radical neck dissection.

An unusual complication of radical neck dissection is presented. Necrosis of the anterior half of the tongue developed gradually within the first week of bilateral neck dissection. The patient had previously received radiotherapy.

Mastectomy and reconstruction--an unusual solution to intractable breast pain.

Breast pain is a common complaint which usually subsides with simple reassurance or sometimes medication. This paper describes the case of a 41-year-old woman suffering from severe non-cyclical breast pain that had proved resistant to a battery of medical treatments. The pain was so disabling that it drove the patient to contemplate suicide. At the patient's request, a bilateral subcutaneous mastectomy with immediate implant reconstruction was performed, resulting in a complete resolution of the pain. Non-cyclical breast pain is less common than cyclical breast pain and tends to be more difficult to treat. This case suggests that mastectomy may be an appropriate option of last resort in the treatment of severe intractable breast pain.

Ruby laser irradiation (694 nm) of human skin biopsies: assessment by electron spin resonance spectroscopy of free radical production and oxidative stress during laser depilation.

Human skin biopsies (hair-bearing scalp skin and non-hair-bearing breast skin) were treated with t-butylhydroperoxide, irradiated with UV light (UVR) or irradiated with 694 nm ruby laser red light. Free-radical production and oxidative stress were assessed with electron spin resonance spectroscopy (ESR) using the ascorbate radical as a marker. In comparison with both UVR and t-butyl-hydroperoxide (which readily induce the ascorbate radical in hair-bearing and hairless skin), 694 nm red light does not result in the formation of the ascorbate radical in detectable concentrations. Spin-trapping experiments with the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) showed that while free radicals could be detected after treatment of skin with t-butylhydroperoxide, radicals could not be trapped after laser treatment. Treatment of lasered skin (containing DMPO) with t-butylhydroperoxide produced radical adducts as well as the ascorbate radical, demonstrating that the laser neither depletes endogenous ascorbate nor the preadministered spin trap. It is concluded that 694 nm red light does not induce oxidative stress in human skin in levels comparable either to t-butyl hydroperoxide or UV light.

Preventing the scars of neonatal intensive care.

Two cases are reported of serious extravasation injuries due to parenteral nutrition in infants born at 24 and 28 weeks' gestation. Major scarring and the need for plastic surgery were prevented by using a technique of subcutaneous hyaluronidase and saline flushing.

Infected sternotomy wounds.

Three babies who developed infection in their median sternotomy wounds are reported. In one child, a retrosternal abscess was drained and in the other two cases, the wounds dehisced. The wound cavities were filled with a rectus abdominis myocutaneous island flap and in each case, the wounds healed primarily. Early flap repair resolved the infection, shortened the hospital stay and provided protection to the exposed mediastinum.

A prosthesis to camouflage indented scars.

Traditional silicone prostheses have been found to be inflexible, heavy, and of poor color match when used on the limbs. Ten patients distressed by contour deformities on their limbs after the wide excision of malignancies or following trauma were fitted with a light-weight prosthesis whose special features include a flexible foam backing, an outer tinted skin, and finely feathered edges that draw the eye away from the margins of the defect. The prosthesis sticks dependably to the skin and is particularly effective when worn under stockings or tights. When reviewed, all patients were continuing to use the device. It is a useful alternative to surgical reconstruction in such patients.

The postauricular fascial flap as an adjunct to Mustardé and Furnas type otoplasty.

Anterior riberation methods of otoplasty have been criticized because of the risk of anterior hematoma that can cause anterior skin necrosis, scarring, and even cartilage destruction caused by infection. As a result, cartilage-sparing otoplasty such as the Mustardé and Furnas types has been increasingly popular. However, postauricular suture extrusion may result, and recurrence rates of up to 25 percent have been recorded. In this study, cartilage-sparing otoplasty is refined by the addition of a postauricular fascial flap to reduce suture extrusion and recurrence rates. Fifty-one patients underwent otoplasty (45 bilateral, six unilateral). This technique involves the elevation of a fascial flap from the postauricular region. A new antihelical fold is then created by Mustardé sutures, and the conchal bowl is rotated by Furnas-type concha-mastoid sutures. The fascial flap is then advanced to cover the sutures with a supplementary vascularized layer to prevent suture extrusion. In addition, the advancement of the flap acts as a postauricular support to prevent recurrence. A natural-looking antihelical fold and helical rim is created by this technique. There were no hematomas. There was recurrence in eight ears (8 percent) in six patients. Two patients requested further surgery. No patients developed suture extrusion or granuloma. This is a simple and intrinsically safe procedure and does not cause irreparable complications such as anterior scarring or skin necrosis. The postauricular fascial flap seems to prevent suture extrusion. It may also help to reduce recurrence rates to acceptable levels.

5-year series of constricted (lop and cup) ear corrections: development of the mastoid hitch as an adjunctive technique.

Despite the multitude of corrective procedures described, adequate surgical correction of the congenital constricted ear remains a challenge. The maintenance of the shape and elevation of the reconstructed upper neohelix poses a particular problem. In the present series, experiences with lop ear correction utilizing standard techniques and the use of the mastoid hitch as a useful adjunct to these procedures are described. A total of 19 ears were reconstructed. There were three type 1, eight type 2a, seven type 2b, and one type 3 deformities (Tanzer classification). A graded sequence of procedures was adopted. Mild deformities were corrected by cartilage scoring techniques; a V-Y advancement of the helical root was added for moderate deformities. Cartilage expansion by a banner flap was required for more severe deformities. A mastoid hitch, whereby the refashioned upper neohelix is sutured to the mastoid fascia, should be used as an adjunct to these procedures to maintain helical elevation and prevent recurrence. Severe type 3 deformities may require autologous auricular reconstruction. Mean follow-up time was 1 year. There were six excellent, seven good, four fair, and two poor results. Two patients who had not had mastoid hitch procedures developed a recurrence of the lop deformity. Adequate surgical correction of constricted ear deformities requires a variety of surgical techniques. The mastoid hitch being used for constricted ear correction has not been described elsewhere. The mastoid hitch is a useful adjunctive procedure that may be used effectively in combination with other procedures.

Intracranial pressure and intracranial volume in children with craniosynostosis.

Intracranial volume and intracranial pressure have been measured in 66 children with craniosynostosis, 48 boys and 18 girls. The premature fusion of skull sutures is assumed to restrict skull growth and predispose to elevated intracranial pressure. Thirteen children (20 percent) had raised intracranial pressure and demonstrated a significant restriction of skull growth. In this series, volume measurement alone, however, did not serve as a reliable predictor that the intracranial pressure was raised.

Ruby laser-assisted hair removal success in relation to anatomic factors and melanin content of hair follicles.

Ruby laser-assisted hair removal is thought to work via selective photothermolysis, which relies on light reaching the deeper layers of skin, and the absorption of light by the target chromophore, melanin. It is therefore possible that efficacy of treatment is affected by anatomic factors that determine the amount of light reaching the hair bulbs (i.e., skin color, depth of intracutaneous hair, epidermal thickness and dermal density) and the melanin content of hair. To examine this hypothesis, a prospective study was performed. Forty-eight volunteers were treated with the Chromos 694 Depilation Ruby Laser at a single standard fluence of 11 J/cm2. Treatment efficacy was determined by measuring hair density at 3 and 7 months after treatment. Epidermal depth and dermal density were measured from 2-mm biopsies taken before treatment, and the intracutaneous hair length was determined from plucked hair. Skin color was assessed using a spectrophotometer, and melanin content of dissolved hair was assessed using spectrophotometry. Efficacy of treatment for each patient was compared with the patient's age, intracutaneous hair length, epidermal depth, dermal density, skin color, and total melanin content and relative eumelanin content of hair. No correlation was found between the efficacy of treatment and age and the various anatomic factors. Patients with higher eumelanin content in their hair had better long-term results (Spearman rank test, p = 0.00219). The results suggested that the efficacy of treatment did not depend solely on the amount of laser light penetrating the skin but correlated well with the eumelanin content of hair. The clinical implication of this finding is discussed.

Two case reports of vinorelbine extravasation: management and review of the literature.

Vinorelbine tartrate (Navelbine, Burroughs Wellcome Company, Research Triangle Park, NC, USA) is a semisynthetic vinca alkaloid approved in many countries for the first-line treatment of patients with advanced non-small-cell lung cancer. It is also used in the treatment of advanced breast and ovarian cancers and lymphoma. Like other vinca alkaloids, Navelbine can cause skin necrosis as a consequence of inadvertent extravasation in surrounding tissues during intravenous administration. In such cases, early treatment is strongly advocated. There is no documented case of vinorelbine extravasation in the literature. The authors herein report two cases successfully treated with hyaluronidase injections plus saline flushout under local anesthesia.