Limit on neutrinoless ßß decay of 136Xe from the first phase of KamLAND-Zen and comparison with the positive claim in 76Ge.

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of (136)Xe. We obtain a lower limit for the neutrinoless double-beta decay half-life of T(1/2)(0ν)>1.9×10(25) yr at 90% C.L. The combined results from KamLAND-Zen and EXO-200 give T(1/2)(0ν)>3.4×10(25) yr at 90% C.L., which corresponds to a Majorana neutrino mass limit of <(120-250) meV based on a representative range of available matrix element calculations. Using those calculations, this result excludes the Majorana neutrino mass range expected from the neutrinoless double-beta decay detection claim in (76)Ge, reported by a part of the Heidelberg-Moscow Collaboration, at more than 97.5% C.L.

Presurgical orthopedic premaxillary alignment in cleft lip and palate reconstruction.

Premaxillary malposition is a difficult problem in cleft lip and palate repair. Orthopedic palatal devices are excellent in positioning the premaxilla, though they are somewhat cumbersome and require complex techniques in adjusting precisely the position of the premaxilla prior to repair. A new technique has been developed for premaxillary repositioning in conjunction with palatal shelf expansion and obturation. The procedure implements microplate fixation anterior to the premaxillary segment and linked to a palatal splint by adjustable elastics. The microplate is inserted through a nasal floor incision and secured by a tight submucosal tunnel through minimal dissection between the prolabium and premaxilla. The last hole of each microplate protrudes through the mucosa and is attached to a pin-retained palatal splint by an elastic chain. Differential tension is applied to the chains to allow gradual repositioning of the protruding maxilla while the splint expands and maintains positioning of the lateral palatal segments. These elastic retractors can be adjusted by staff in the outpatient office. During the past 2 years, this technique has been used successfully in 21 consecutive patients with unilateral or bilateral cleft lip and palate. Its technical ease and design allows simple adjustments to control premaxillary positioning and growth before definitive surgical closure.

Enophthalmos following orbital transposition for craniofacial malformations.

This is a retrospective study of the frequency and factors that portend enophthalmos following orbital osteotomies and transposition for craniofacial malformations. Clinically obvious postoperative enophthalmos (POE) was noted in 23 (37.7 percent) of 61 patients undergoing such procedures. Postoperative enophthalmos was observed in 86 percent of Apert patients who had combined anteromedial orbital transposition and in 48 percent of patients with hypertelorbitism who had standard 360-degree osteotomies. In contrast, the incidence of postoperative enophthalmos was 21 percent following frontofacial (monobloc) or subcranial (Le Fort III) advancement. Postoperative enophthalmos also correlated with the occurrence of orbital fracture/fragmentation and with disruption of the periorbita. This study underscores the importance of establishing the correct relationship of the globe to the orbital rim (euophthalmos) while maintaining the spatial position of the eye, especially its anterior projection. Postoperative enophthalmos can be prevented by inserting bone grafts into orbital osteotomy gaps, correcting orbital volume/morphology following floor or wall outfracture/fragmentation, and preserving the periorbital supporting system.

The healing of bone and cartilage.

Transplantation of bone should be preceded by careful assessment of the recipient site. The function of the transplanted bone as an interposition graft, as an onlay graft, or in restoration or construction of a missing part of the skeleton must be considered. Cortical bone provides superior mechanical strength and can be incorporated with plate fixation to span interposition defects. Membranous bone used as onlay grafts for augmentation of craniofacial skeletal contour has been shown to be superior to endochondral grafts in maintaining volume. The use of rigid fixation to secure onlay grafts may eliminate the differences in resorption seen with membranous versus endochondral bone. The vascularity and quality of soft tissue at the recipient site may necessitate the use of vascularized bone or composite free tissue transfer. The calvarium is the most popular donor site for bone grafts used in craniofacial skeletal procedures. This membranous bone undergoes less resorption and revascularizes faster than endochondral bone. Cranial bone has excellent mechanical strength due to its large cortical component. The calvarial donor site causes less discomfort to the patient compared with rib or iliac crest, and the scar is well hidden. Harvesting and shaping cranial bone require special expertise, and there is potential morbidity. In cartilage transplantation, the surgeon must take into account the properties of viscoelasticity, the intrinsic balanced system of forces, and immunologic privilege. Cartilage deformed by an external force will tend to return to its original shape unless the deformation is maintained for several months. Surgical carving produces changes in the balance of intrinsic tensile and expansile forces, causing distortion in cartilage shape. Distortion can be minimized by carving in balanced cross-section. Carved cartilage grafts should be used for special indications in rhinoplasty. Autogenous cartilage is the framework of choice in ear construction. Composite grafts incorporating cartilage have been used successfully in eyelid reconstruction. Fresh autogenous cartilage is preferable to preserved allogeneic sources, as the latter undergo eventual resorption because there are no viable chondrocytes to maintain the matrix.

Gastric secretory and humoral responses to anticipated feeding in five men.

It is believed that humans anticipate appetizing meals by increasing vagally mediated gastric acid secretion. Studies were conducted on 5 normal male volunteers to characterize further the secretory response to anticipated meals. Plasma gastrin and glucose levels were monitored to assess the possibility that these humoral factors participated in the observed secretory changes. Subjects were not fed for 22 hr and were intubated at 10 AM. Basal gastric collections were begun, and at 1 PM on different days, subjects either (a) selected meals of choice prepared in their presence for 1 hr before nasogastric tube withdrawal and meal ingestion or (b) were not food-teased or fed. Gastric collections were obtained every 10 min during the "test" hour (1-2 PM) during both (a) and (b) studies and titrated for gastric acid. Blood samples for plasma glucose and RIA gastrin were obtained during basal and test hours every 10 min. Pentagastrin-stimulated maximal acid output studies were conducted on all subjects on separate days. Results showed a progressive and statistically significant rise in gastric acid secretion when an appetizing, self-selected meal was anticipated. The magnitude of this rise was 55% of the mean pentagastrin-induced acid response. This acid response did not correlate with changes in plasma glucose or gastrin. The study demonstrated that pure psychic stimulation may be as effective an acid stimulant as sham feeding.