Recurrences of thyroid well differentiated cancer: ultrasonography-guided surgical treatment.

AIM: Differentiated thyroid carcinomas (DTC) have a favourable outlook overall. Cornerstone of treatment is total thyroidectomy (TT), followed, if needed, by radiometabolic therapy. Such lesions however show a definite tendency to recur (about 35% of cases), generally in the first decade of follow-up: in 70% of patients such recurrence is local. Surgical resection is the only curative treatment option for local recurrence of well-differentiated thyroid cancer. Intraoperative ultrasonography (US) can be of significant help in facilitating localization and complete resection of lesions. The aim of the study was to review the authors' own experience with the use of such diagnostic method in the clinical setting of thyroid neoplasm recurrence. METHODS: Between January 2005 and March 2008 31 patients with DTC recurrences underwent intraoperative US exploration. Recurrences were easily identified and resected in all patients. Postoperative tireoglobuline (TG) was undetectable. RESULTS: In all 31 patients preoperative US confirmed the presence of the lesion. In 26 patients digital exploration of the surgical field did not yield a definitively positive finding, whereas in 5 the lesion was easily palpable. Intraoperative US revealed the presence of pathologic tissue in all cases, with examination time ranging from 4 to 14 minutes (median 8 minutes). In all cases surgical resection was complete, with pathologic confirmation of the sample, and no necessity to extend ablation. CONCLUSION: Intraoperative US can be of significant help in the identification of DTC recurrences, in particular when lesion dimensions are smaller than 10 mm in diameter and can facilitate a more radical excision of the tumor in a surgical field were anatomical landmarks can be altered by previous surgery and/or radiometabolic therapy.

Antibiotic iontophoresis in the treatment of burn perichondritis of the rabbit ear.

Perichondritis of the pinna is a serious late infection of burns involving the ear. The avascular nature of this injury renders systemic antibiotic therapy ineffective in delivering adequate levels of drug to the area to provide antimicrobial activity. Treatment has traditionally been surgery in some form, resulting in further disfigurement of the damaged cartilagenous framework. Iontophoresis, a method of dispersing charged particles through a relatively impermeable membrane by a light electrical field, appears to be a feasible method of antibiotic delivery. This initial pilot study investigated the development of perichondritic-like burns in ten rabbit ears, and techniques for gentamicin iontophoresis and assay in devitalized cartilage. Five rabbits, with ear burns simulating perichondritis, were treated with gentamicin iontophoresis on one ear and gentamicin-soaked gauze on the other. Resulting assays of the ear cartilages, after four treatments over a 2-day period, demonstrated a nearly twenty-fold increase in gentamicin levels in the iontophoresis-treated ears, compared to low levels in the soaked ears. Systemic absorption was negligible in all rabbits.

Uvulopalatopharyngoplasty: postoperative management and evaluation of results.

Since the earliest report of success with the uvulopalatopharyngoplasty (UPPP) operation, several authors have reported less than optimal results in their experience with the procedure. Part of the difficulty in evaluating the objective results of postoperative sleep studies has been the variations in reporting data. In addition, no standard of postoperative care, including analgesia, and immediate postoperative monitoring has been described. Our experience with 42 UPPP patients (34 studied with preoperative and postoperative polysomnography) indicates a 76% response (56% successes, and an additional 20% with limited success) with use of the more stringent criteria described recently. We discuss our management of these cases, including postoperative oxygen saturation monitoring and avoidance of narcotic analgesia as necessary factors for success with this operation.

Discovery of the Griffiths phase in the itinerant magnetic semiconductor Fe1-xCoxS2.

Critical points that can be suppressed to zero temperature are interesting because quantum fluctuations have been shown to dramatically alter electron gas properties. Here, the metal formed by Co doping the paramagnetic insulator FeS2, Fe1-xCoxS2 is demonstrated to order ferromagnetically at x > xc = 0.01+/-0.005, where we observe unusual transport, magnetic, and thermodynamic properties. We show that this magnetic semiconductor undergoes a percolative magnetic transition with distinct similarities to the Griffiths phase, including singular behavior at xc and zero temperature.

Spin disorder and order in quasi-2D triangular Heisenberg antiferromagnets: comparative study of FeGa2S4, Fe2Ga2S5, and NiGa2S4.

Our single crystal study reveals that the single-layer S=2 triangular Heisenberg antiferromagnet FeGa2S4 forms a frozen spin-disordered state, similar to the S=1 isostructural magnet NiGa2S4. In this state, the magnetic specific heat C{M} is not only insensitive to the field, but shows a T2 dependence that scales to C{M} of NiGa2S4, suggesting the same underlying mechanism of the 2D coherent behavior. In contrast, the bilayer system Fe2Ga2S5 exhibits a 3D antiferromagnetic order.

Metallic spin-liquid behavior of the geometrically frustrated Kondo lattice.

Strongly frustrated magnetism of the metallic pyrochlore oxide Pr2Ir2O7 has been revealed by single crystal study. While Pr 4f moments have an antiferromagnetic RKKY interaction energy scale of /T*/ = 20 K mediated by Ir 5d-conduction electrons, no magnetic long-range order is found except for partial spin freezing at 120 mK. Instead, the Kondo effect, including a lnT dependence in the resistivity, emerges and leads to a partial screening of the moments below /T*/. Our results indicate that the underscreened moments show spin-liquid behavior below a renormalized correlation scale of 1.7 K.

Low-loss 1.3-microm GaInNAs saturable Bragg reflector for high-power picosecond neodymium lasers.

A novel low-loss, single-step-growth 1.3-microm GaInNAs saturable Bragg reflector mode-locking element has been developed. Combined radial thickness and postgrowth annealing control have permitted a tuning range of 46 nm for passive mode locking to be demonstrated from one wafer. With this structure, stabilized mode locking was obtained from quasi-cw diode-pumped Nd:YLF and Nd:YALO lasers operating at 1314 and 1342 nm, respectively, with average on-time output powers of as much as 20 W and pulse durations as low as 22 ps.