Postoperative laryngoscopy in thyroid surgery: proper timing to detect recurrent laryngeal nerve injury

BACKGROUND: There is currently a lack of consensus to support the proper timing for postoperative laryngoscopy that is reliable to diagnose recurrent laryngeal nerve palsy (RLNP) after thyroid surgery. The purpose of this study was to investigate the impact of different time intervals of fiber-optic nasolaryngoscopy (FNL) on the diagnosis of RLNP. METHOD: FNL was performed postoperatively at day 0 (T1), at second day post-op (T2), and +2 weeks (T3). For patients with RLNP, repeated examinations were performed at +2 (T4), +6 (T5), and +12 months (T6). RESULTS: Four hundred thirty-four patients appear for postoperative FNL, providing 825 nerves at risk. Permanent RLNP occurred in 0.7%, temporary RLNP in 6.7%. RLNP rate was 6.4% at T1, 6.7% at T2, 4.8% at T3, 2.5% at T4, 0.8% at T5, and 0.7% at T6. Full recovery of vocal cord function was confirmed after rehabilitation in 87.5% of cases at T5 and 89% in T6. T2 was significantly superior to T3 in terms of diagnosis of RLNP (P < 0.05). Of patients at T2, 10.7% did not see any reason to FNL because of their normal voice register. CONCLUSION: FNL is essential for the detection of vocal cord paralysis after thyroidectomy. We report different time evaluation criteria of vocal cord motility with great and significant variability of results. Second day post-op inspection of the larynx (T2) is suggested. Symptomatic voice assessment is insufficient

Spectral signatures of breaking of ensemble equivalence

This thesis explores Breaking of Ensemble Equivalence (BEE) in random graph models by examining the spectral properties of adjacency matrices. The goal is to identify spectral characteristics that differentiate random graph ensembles, enhancing the understanding of complex network structures and behaviors. The research encompasses both theoretical analysis and practical applications, including a chapter on simulations and sampling methods.Chapter 1 introduces basic random graph theory and emphasizes the importance of maximum entropy models in real-world network modeling. It defines BEE and its characterization within statistical mechanics, highlighting the natural differences between canonical and microcanonical ensembles. It then introduces spectral theory of random graphs and why it is utilized to investigate BEE.Chapter 2 proposes a conjecture linking BEE to a gap between the expectations of the largest eigenvalue in the canonical and microcanonical ensembles, proving it for homogeneous graphs.Chapter 3 examines Chung-Lu random graphs, establishing central limit theorems for the largest eigenvalue and its eigenvector.Chapter 4 verifies the conjecture for inhomogeneous graphs, computing the expected largest eigenvalue of the configuration model.Chapter 5 offers numerical evidence through simulations, after a brief introduction to graph sampling. The thesis concludes with a summary of findings and suggestions for future research.NWO024.002.003Analysis and Stochastic

Neuroendocrine carcinomas of the breast

INTRODUCTION: Neuroendocrine (NE) breast cancers encompass a heterogeneous group of tumours showing morphological features similar to those of NE neoplasms of the gut and lung and expressing one or more neuroendocrine markers (neuron specific enolase, chromogranins synaptophysin) in at least 50% of tumour cells. They are rare lesions representing about 2-3% of all breast cancers and affecting more frequently elderly patients. AIM: Prospective observational study is to analyse the clinico-pathological aspects of NE carcinomas of the breast undergone surgical resection compared to breast carcinomas with a minor neuroendocrine component and to conventional invasive ductal or lobular cancers. MATERIAL AND METHOD: Thirty-five consecutive breast carcinomas showing morphological features suggestive of an endocrine differentiation were selected among breast cancers undergone surgical treatment during the period of January 1979-December 2004. RESULTS: The 35 patients were divided into two categories: 13 neuroendocrine carcinomas (NECs) and 22 ductal carcinomas with a minor neuroendocrine component (DC-NE). The average follow-up was 60 months. The patients with CNE developed breast cancer in an advanced age compared to the patients with infiltrating ductal carcinoma NAS or infiltrating lobular carcinoma. We did not find recurrent disease in the NEC group, while it was observed in 2 patients (9%) with DC-NE, in 6 cases (17%) with infiltrating ductal carcinoma NAS and in 7 cases (20%) with infiltrating lobular carcinoma. DISCUSSION: The CNE compared with the infiltrating ductal and lobular carcinoma are statistically different in relation to the expression of the receptor of c-erb-B2, p53, progesterone, for the lymph node state at diagnosis and the risk of reappearance of breast tumour. Our study confirms the choice to consider the neuroendocrine carcinoma of the breast as a separate histological group and seems to suggest a less aggressiveness of this type of tumou

Dissection and hemostasis with hydroxilated polyvinyl acetal tampons in open thyroid surgery

BACKGROUND: The essential objectives for thyroidectomy are: avoidance of injury to the recurrent laryngeal nerves, conservation of the parathyroid glands, an accurate haemostasis and an excellent cosmesis. In the last 10 years major improvements and new technologies have been proposed and applied in thyroid surgery; among these mini-invasive thyroidectomy, regional anaesthesia and intraoperative neuromonitoring, and new devices for achieving dissection and haemostasis. Minor bleeding from small vessels could be a major complication in thyroid surgery. The purpose of ligating vessels is to maintain the surgical site free from an excess of blood and reduce blood loss in the patient. MATERIALS AND METHODS: Hydroxylated polyvinyl acetal tampons (HPA) are made by a synthetic, open cell foam structure able to absorb fluids up to 25 times the initial weight. We tested their efficacy for small bleeding control and tissue dissection during several thyroid procedures. RESULTS: HPA tampons have been found extremely useful to absorb blood coming from minor and diffuse loss, helping to control bleeding by a combined action of fluid absorption and local compression. The porous design of the tampon allows the use of the suction device right through the tampon itself. Thanks to the initial mildly hard consistency, we also used HPA tampons as dissecting instruments. CONCLUSION: In our experience the use of HPA tampons resulted extremely efficient for minor bleeding control, fluids removal and tissue dissection during thyroid surgery

Total orthotopic small bowel transplantation in swine under FK 506

Previous experimental studies in rodents and in dogs have established the efficacy of FK 506 in controlling the immunologic events following small bowel or multivisceral transplantation.1–5 To complete the assessment of FK 506 in experimental small bowel transplantation, we present here our experience with the frequently used swine model

Regular consumption of a balanced salmon-based salty snack does not affect energy intake, body composition and biochemical parameters in healthy volunteers

An inverse relationship between meal frequency and body weight has been observed in several studies: however, little information is available on the effects of a snack consumption on energy and nutrient intakes in adults. In this study, 19 healthy volunteers consumed daily for 3 weeks, in a cross-over design, one of two isocaloric snacks (bread with salmon spread or bread with salami). Diet composition, anthropometrics, blood pressure, lipid and fatty acid profiles, fasting plasma glucose levels and high sensitivity C reactive protein (hs-CRP) were assessed at the beginning of the study and before and after each dietary period. The inclusion of a mid afternoon snack in the standard meal pattern (breakfast, lunch, dinner) was associated with a significant reduction in energy intake at dinner (the reduction being larger after the snack prepared with the salmon spread); the total daily caloric intake, however, was not changed by the snack consumption, since the snack caloric intake was fully compensated by the lower dinner energy intake. No significant change has been observed in any of the measured biochemical or anthropometric parameters, even if a trend toward a plasma hs-CRP reduction and toward a more favourable HUFA index was observed after the salmon spread snack consumption. These observations indicate that the regular consumption of a balanced mid afternoon snack has no adverse effects on energy intake and biochemical parameters of healthy adults with a moderately active lifestyle; the snack consumption results, however, in different distributions of the energy intake among meals. The snack composition (salmon or salami) may further influence these effects

A spectral signature of breaking of ensemble equivalence for constrained random graphs

For random systems subject to a constraint, the microcanonical ensemble requires the constraint to be met by every realisation ('hard constraint'), while the canonical ensemble requires the constraint to be met only on average ('soft constraint'). It is known that for random graphs subject to topological constraints breaking of ensemble equivalence may occur when the size of the graph tends to infinity, signalled by a non-vanishing specific relative entropy of the two ensembles. We investigate to what extent breaking of ensemble equivalence is manifested through the largest eigenvalue of the adjacency matrix of the graph. We consider two examples of constraints in the dense regime: (1) fix the degrees of the vertices (= the degree sequence); (2) fix the sum of the degrees of the vertices (= twice the number of edges). Example (1) imposes an extensive number of local constraints and is known to lead to breaking of ensemble equivalence. Example (2) imposes a single global constraint and is known to lead to ensemble equivalence. Our working hypothesis is that breaking of ensemble equivalence corresponds to a non-vanishing difference of the expected values of the largest eigenvalue under the two ensembles. We verify that, in the limit as the size of the graph tends to infinity, the difference between the expected values of the largest eigenvalue in the two ensembles does not vanish for (1) and vanishes for (2). A key tool in our analysis is a transfer method that uses relative entropy to determine whether probabilistic estimates can be carried over from the canonical ensemble to the microcanonical ensemble, and illustrates how breaking of ensemble equivalence may prevent this from being possible.Analysis and Stochastic

Quantum Information Processing and Relativistic Quantum Fields

It is shown that an ideal measurement of a one-particle wave packet state of a relativistic quantum field in Minkowski spacetime enables superluminal signalling. The result holds for a measurement that takes place over an intervention region in spacetime whose extent in time in some frame is longer than the light-crossing time of the packet in that frame. Moreover, these results are shown to apply not only to ideal measurements but also to unitary transformations that rotate two orthogonal one-particle states into each other. In light of these observations, possible restrictions on the allowed types of intervention are considered. A more physical approach to such questions is to construct explicit models of the interventions as interactions between the field and other quantum systems such as detectors. The prototypical Unruh-DeWitt detector couples to the field operator itself and so most likely respects relativistic causality. On the other hand, detector models which couple to a finite set of frequencies of field modes are shown to lead to superluminal signalling. Such detectors do, however, provide successful phenomenological models of atom-qubits interacting with quantum fields in a cavity but are valid only on time scales many orders of magnitude larger than the light-crossing time of the cavity.Comment: 16 pages, 2 figures. Improved abstract and discussion of 'ideal' measurements. References to previous work adde