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Driven by the need of a simple method to arrive at rather accurate molecular mass key data for different lignin samples across different laboratories, we revisited thoroughly the different aspects that comprise the determination of molecular weight key data of lignins by means of gel permeation chromatography. We considered setup issues and their effect on calibration, implications emerging from sample preparation, issues connected to data acquisition, and effects of raw data evaluation. Considering identified key issues, we propose a standardized setup in connection with a standardized data treatment that ensures the generation of precise GPC results. The introduction of an additional lignin-type depending correction factor, which is delineated using averaged bidimensional NMR-based advanced structural information obtained for a given lignin type, allows us to account for system-inherent bias, rendering the precise measurements de facto accurate.

One crucial component within the efforts aiming at the valorisation of lignin is a rather precise knowledge regarding its structural features in terms of the amounts of aliphatic and phenolic hydroxyl groups, the amount of non-phenolic end groups, and the nature of interunit bonding motifs including their abundances. For achieving a complete characterisation, these data are best to be interpreted in connection with the molecular mass key data describing the oligomeric lignin chains, namely the number average molecular weight Mn, the weight average molecular weight Mw, and the polydispersity PD. Especially the latter one is often referred to when the discussion comes to the quality of polymeric or oligomeric sample: the smaller the PD, the better the polymer with respect to subsequent (chemical) modifications. Within the GPC-based determination of the above-mentioned key data like the PD for a given lignin sample, a meaningful calibration of the instrumentation, as well as the use of suitable detectors, are of paramount importance: a misled estimation of the “expected” molecular weight of a lignin sample might lead to a poor choice of the range of molecular weights of the standards used for calibration; the wrong detector-type lacks sensitivity. The range of the molecular weights covered in the calibration, however, does affect significantly the results obtained in the measurements of the lignin samples especially with respect to the polydispersity, and a non-suitable detector neglects the extremes. So-obtained astonishingly good, or unexpectedly bad polydispersities eventually lead to wrong conclusions and decisions concerning future actions. We have developed a transparent and robust protocol for the gel-permeation chromatography-based characterisation of plant-derived polyphenols in general, and lignins in particular. After systematically evaluating i) the influence of the range of molecular weights used for the calibration of the analytical set-up, ii) the influe

Intraoperative nerve monitoring (IONM) aimed at reducing the injuries of recurrent laryngeal nerve during thyroidectomy is controversial. We conducted a meta-analysis to assess the incidence of nerve injuries with or without IONM. Studies published from January 1994 to February 2012 in English language on humans were identified. Heterogeneity of studies was checked by the Higgins test. Summary estimates of predictive values of injury were made using the Mantel-Haenszel test based on the fixed-effects model. Publication bias was assessed by a funnel plot and Egger’s method. Eight articles were selected accounting a total of 5257 nerves at risk. IONM revealed a significant impact in preventing transient injuries (positive predictive value = 5% [95% CI: 2-8], negative = 96% [95% CI: 91-100], relative risk = 0.73 [95% CI: 0.54-0.98], p = 0.035), whereas they failed to demonstrate effect on permanent injuries (positive predictive value = 2% [95% CI: 0.6-3.8], negative 99% [95% CI: 97-100], relative risk = 0.73 [95% CI: 0.44-1.23], p = 0.235). This meta-analysis demonstrated the merit of IONM in preventing transient injury during thyroidectomy. No advantage was found in permanent injuries.

Long saphenous vein (LSV) stripping is the most common surgical procedure in patients affected by varicose disease of the lower limbs. Reactive oxygen metabolites (ROM) generation plays a crucial role in chronic venous insufficiency (CVI). The aim of this study was to investigate whether ROM generation is increased in patients affected by varicose disease versus healthy controls and whether LSV stripping has a positive effect on the local production of ROM. The local production of ROM was assessed measuring hydroperoxides in the blood collected from the leg of 30 patients consecutively undergoing LSV stripping and 30 controls. In both the patient group and the control group, the test was repeated 30 days later. We found that ROM levels before surgery are higher in varicose vein patients than in controls ( p <.0001) and that ROM are significantly reduced 30 days after LSV stripping ( p <.0001). At that time point, no significant differences between patients and controls was found. We also found that sex and age do not affect ROM concentration in patients and controls, either before or after surgery. In conclusion, our data indicate that CVI is characterized by significant oxidative stress and that LSV stripping is able to normalize local production of ROM in patients with varicose disease of the lower limbs. We suggest that measurement of ROM might be useful to test the positive effects of LSV stripping in these patients.

Objective: Total thyroidectomy with modified radical neck dissection (MRND) is the treatment of choice of papillary thyroid carcinoma (PTC) with lymphnodal involvement. The aim of this study was to describe an alternative lateral neck access to perform lymph nodes sampling and/or neck dissection via extra-thyroideal space (MRND vets). Methods: Twenty-one consecutive patients with papillary thyroid carcinoma were included. Lymph node sampling and modified radical neck dissection, unilateral or bilateral, were performed acceding via a lateral dissection through a traditional Kocher incision, running along the medial fascia of the neck, posteriorly to the sterno-cleidomastoideus muscle (SCM), and finally reaching the neurovascular bundle. Results: Mean age was 38.35 ± 13.66 years. Seventeen patients were women, and 4 were men. Mean tumor size was 2.5 ± 1 cm. Total thyroidectomy with lymph node dissection of the central compartment associated to modified radical neck dissection was performed in 13 patients. Among these, five patients had a preoperative diagnosis of latero-cervical lymph node metastases, and eight had a perioperative diagnosis of metastases of the extensive sampling of the lower third of the jugular chain. Metastatic lymph nodes were found in 89 out of 529 of the lymph nodes dissected. Conclusion: The MNRD vets access for modified lateral neck dissection seems to carry a lower risk in terms of specific morbility and allows a quicker recovery and a better cosmetic result. This access has to be considered as a less invasive procedure compared with the other surgical accesses for the radical modified lateral neck dissection.

Objective: We describe the operative technique of diagnostic lobectomy (DL), for follicular thyroid neoplasm. Methods: The study is based on 48 consecutive patients operated on from January 1997 to December 2001, for follicular neoplasms of the thyroid gland. We define DL as a surgical procedure that includes a total lobectomy and isthmusectomy with preservation of the omolateral recurrent laryngeal nerve, and parathyroid glands, avoiding to digitally explore the controlateral lobe. In fact the possible necessity of a re-entry in the prior explored field for completion thyroidectomy presents increased risk of complications. Results: There were 41 follicular adenomas and 7 follicular carcinomas. In the 7 patients with thyroid cancer completion thyroidectomy was performed 2 weeks after the first surgical intervention. Completion of thyroidectomy was performed in a totally clean environment with normal anatomical cleavage plains without risk of injuries to the laryngeal nerves and parathyroid glands. Conclusions: DL is a safe procedure and should be considered as a suitable surgical procedure in patients with follicular-structured lesions of the thyroid gland. Additional study is required before DL should be accepted as the elective diagnostic/therapeutic approach for patients with follicular neoplasms of the thyroid gland.

A rare case of synchronous bilateral testicular germ cell tumor of different histological type is described. We report the case of a 39-year-old man with this unusual condition and discuss the value of the histopathological diagnosis in therapy and prognosis. A thorough review of the literature is also presented, and for the first time the precise histological subtype of each reported tumor, as diagnosed by the authors of the original paper, is illustrated. Copyright (C) 2003 S. Karger AG, Basel.

The occurrence of thyroid malignancy is considered a rare event in hyperthyroid patients. With the aim of assessing the clinical relevance of this association, we have analyzed the incidence of thyroid cancer in hyperthyroid patients treated by surgery. The incidence of thyroid cancer was retrospectively evaluated in 202 hyperthyroid patients who underwent thyroidectomy during a twenty-year period. A thyroid cancer was diagnosed in 12 cases (5.9 per cent). Histologic examination revealed the presence of papillary carcinoma in 9 cases, follicular carcinoma in 1 case and Hürthle cell carcinoma in 2 cases. The association between thyroid cancer and hyperthyroidism was more frequent in toxic adenomas (17.8 per cent) than in toxic diffuse (5.3 per cent) or multinodular goiters (1.7 per cent). In 8 patients they presented as an occult carcinoma (maximum diameter below 1 cm), but unfavourable histologic features, such as local invasiveness and multifocality, were found in 5 of them. Follow-up data indicate that all 12 patients are currently alive and apparently free of disease. Hyperthyroid patients, particularly those affected by toxic adenomas, should be carefully evaluated to exclude the presence of concurrent malignancy. A special attention should be made moreover to the presence of "occult" lesions that, in our study was characterized in a higher proportion (62.5 per cent) of cases, by unfavourable histologic features.

A retrospective study has been carried out to evaluate the prevalence of malignant thyroid tumors in 202 patients submitted to surgery for hyperthyroidism. Thyroid cancer was diagnosed in 12 cases (5.9%); the final histologic examination revealed nine papillary carcinomas, one follicular carcinoma, and two Hürthle cell carcinomas. Concurrence of hyperthyroidism and thyroid cancer was more frequent in patients with single toxic adenomas than in those with toxic diffuse or multinodular goiters. In five cases thyroid malignancy was detected in the context of the hyperthyroid lesion (three toxic adenomas and two diffuse goiters). In eight patients the malignant lesion showed a maximum diameter of less than 1 cm, although in five of these cases unfavorable histologic features, such as minimal capsular invasion or multifocality, were present. All patients presenting with thyroid cancer are currently alive and apparently free of residual disease. It is concluded that hyperthyroid patients, particularly those with single toxic adenomas, should be carefully evaluated to exclude the presence of an associated malignancy and to plan the most appropriate therapeutic options.