2-step lignin-first catalytic fractionation with bifunctional Pd/ß-zeolite catalyst in a flow-through reactor.

This work demonstrates an additive and hydrogen-free 2-step lignin-first fractionation in flow-through. First, solvolytic delignification renders lignin liquors with its native chemical structure largely intact; and second, ß-zeolite catalytic depolymerization of these liquors leads to similar monomer yields as the corresponding 1-step fractionation process. Higher delignification temperatures lead to slightly lower ß-O-4 content in the solvated lignin, but does not affect significantly the monomer yield, so a higher temperature was overall preferred as it promotes faster delignification. Deposition of Pd on ß-zeolite resulted in a bifunctional hydrogenation/dehydration catalyst, tested during the catalytic depolymerization of solvated lignin with and without hydrogen addition. Pd/ß-zeolite displays synergistic effects (compared to the Pd/γ-Al2O3 and ß-zeolite tested individually and as a mixed bed), resulting in higher monomer yield. This is likely caused by increased acidity and the proximity between the metallic and acid active sites. Furthermore, different ß-zeolite with varying SAR and textural properties were studied to shed light onto the effect of acidity and porosity in the stabilization of lignin monomers. While some of the catalysts showed stable performance, characterization of the spent catalyst reveals Al leaching (causing acidity loss and changes in textural properties), and some degree of coking and Pd sintering.

Spindle epithelial tumour with thymus-like differentiation: report of two cases.

Spindle epithelial tumour with thymus-like differentiation (SETTLE) is a very rare neck malignancy arising from thymic tissue or branchial pouch, mostly seen in the early decades of life. SETTLE is thought to be a low-grade neoplasm but distant metastases have been reported. Fewer than 50 cases have been reported in the PubMed database. We report on the four-year follow-up for a 13-year-old boy, with no signs of recurrence or distant metastasis. In addition, a 45-year-old woman was admitted to hospital with neck mass. Fine-needle aspiration biopsy was compatible with medullary thyroid carcinoma but serum levels of calcitonin were normal. Total thyroidectomy and central compartment lymph node dissection was planned with an initial diagnosis of medullary thyroid carcinoma. At surgery, frozen section analysis converted our diagnosis to SETTLE and the intraoperative strategy was changed. SETTLE should be considered in a patient with normal serum calcitonin levels in the presence of suspicious medullary thyroid carcinoma at fine-needle aspiration biopsy. Frozen section analysis may help to manage the intraoperative strategy. This report describes the first case of SETTLE successfully diagnosed by frozen section analysis.

Parathyromatosis: a very rare cause of recurrent primary hyperparathyroidism - case report and review of the literature.

Parathyromatosis is a rare entity and usually appears as a consequence of the seeding on previous parathyroid surgery which was applied for the secondary hyperparathyroidism. A 63-year-old woman presented with a history of subtotal thyroidectomy 20 years ago and parathyroidectomy due to primary hyperparathyroidism (PHPT) four years ago. Imaging methods revealed multiple parathyromatosis foci on subcutaneous tissue of the neck. En-bloc resection was performed and pathological examination confirmed the diagnosis of parathyromatosis. After an uneventful 10 months, biochemical and radiological tests revealed recurrence on bilateral thyroid lodges. En-bloc resection was performed. The patient has remained well for 24 months after the second operation and has been followed-up with normal parathormone and serum calcium values. To the best of our knowledge, this report describes the twenty-first case of parathyromatosis in PHPT setting in the literature. It should be kept in mind that parathyromatosis may recur at different sites in the neck even in patients with PHPT.

Tumor-associated tissue eosinophilia as a prognostic factor in squamous cell carcinoma of the larynx.

Inflammatory infiltration with eosinophilia in or around the tumoral tissue varies among the cases with invasive squamous cell carcinoma of the larynx. The aim of this study was to investigate the possible role of the tumor-associated tissue eosinophilia (TATE) as a predictive factor for the metastatic status in laryngeal squamous cell carcinoma in patients who had neck dissections. One hundred consecutive specimens from the patients who had been treated surgically for invasive squamous cell carcinoma of the larynx were re-evaluated in terms of TATE. Based on the eosinophil counts per 10 high power field (HPF), the cases were grouped into three different categories (I, II, III) according to three different cut off values (A, B, C). The number of eosinophil cells per 10 HPF for the groups were defined as: IA: 0-10; IB: 11-29; IC: 30 and greater; IIA: 0-20; IIB: 21-39; IIC: 40 and greater; IIIA: 0-30; IIIB: 31-49; IIIC: 50 and greater. Statistical significance between tissue eosinophil counts of the metastatic and non-metastatic lymph node groups were evaluated. This study comprised 97 male and three female patients with squamous cell carcinoma of the larynx (mean age 59.9). Forty-five were well differentiated, 50 were moderately differentiated and five were poorly differentiated invasive squamous cell carcinoma. At least one lymph node metastasis was observed in 34 cases. Eosinophil counts varied between 1 and 138 per 10 HPF in the tumor and/or peritumoral areas. In the three distinct categories with three different cut off values of eosinophil cell counts among nonmetastatic cases and cases with lymph node metastasis, correlation of eosinophil counts with lymph node metastasis were statistically insignificant (Crosstabs, χ(2)). Although in the series, numerical values of the TATE seem to be increased in patients with laryngeal squamous cell carcinoma with lymph node metastasis, this fact has not been confirmed with statistical analysis.

Comparison of nasal cytology and symptom scores in patients with seasonal allergic rhinitis, before and after treatment.

OBJECTIVE: To evaluate symptom scores and nasal smear cytology findings in seasonal allergic rhinitis patients, before and after treatment. METHODS: Twenty-nine consecutive adult patients with seasonal allergic rhinitis were evaluated prospectively. They received mometasone furoate nasal spray and cetirizine for 21 days. Nasal and ocular symptom scores were recorded before and after treatment. Nasal cytology was also assessed as a means of determining treatment. RESULTS: The combined use of an intranasal corticosteroid and an oral antihistamine caused a significant improvement in nasal and ocular symptom scores. Cytological evaluation revealed significant reduction in nasal eosinophil, neutrophil and goblet cell counts after three weeks' treatment. CONCLUSION: Symptom scoring systems are widely used for the evaluation of drug efficacy in allergic rhinitis treatment. When investigating the disease and evaluating treatment efficacy, objective as well as subjective methods are needed. Nasal cytological assessment is a simple, objective method which provides valuable information about the nasal mucosa.

Glial heterotopia of the middle ear.

A choristoma is the presence of histologically normal tissue in an area where it is not normally located. The most frequently reported choristoma of the middle ear is salivary choristoma. Heterotopic brain tissue is very uncommon in the middle ear and mastoid. We present a rare case of glial choristoma of the middle ear, together with a review of the literature.