[Clinical and anatomic study of preserving parathyroid specific adipose attachments in total thyroidectomy].

Objective: To discuss the anatomical characteristic and important role of specific adipose attachments in preserving parathyroid function in total thyroidectomy. Methods: Parathyroid glands of 91 cases underwent total thyroidectomy in Department of General Surgery, Beijing Hospital from January to November 2015 were observed prospectively. There were 19 male and 72 female patients, aging from 25 to 74 years with an average age of (52±12) years. Preoperative ultrasound examination, analysis of intraoperative high definition images, and postoperative pathological examination were used to detect the origins of the parathyroid micro vascular structures and the characteristics of parathyroid specific adipose attachments. Parathyroid specific adipose attachments preserving technique was used in all procedures. The results of parathyroid hormone (PTH), serum calcium and phosphorus were compared pre- and 1-month post-operatively. Paired t test was statistically used to analyze data. Results: Parathyroid micro vascular vessels were closely attached to parathyroid, and they were mainly originated from inside and (or) outside thyroid. Twenty patients received intraoperative high definition images analysis, 62 parathyroids were detected, in which 48 parathyroids (77.4%) had its specific adipose attachments. Lymphatic tissues could be distinguished from adipose tissue using carbon nanoparticles lymphatic tracer technique, which resulted in better preservation of parathyroid specific adipose attachments. There was no significant difference in PTH ((39±17) ng/L vs. (30±16) ng/L), serum calcium ((2.23±0.10) mmol/L vs. (2.20±0.14) mmol/L) and phosphorus ((1.27±0.20) mmol/L vs.(1.26±0.25) mmol/L) pre- and 1-month post-operatively (P>0.05). Conclusions: Preservation of parathyroid specific adipose attachments in total thyroidectomy could result in better protection of parathyroid micro vascular structure and function. It could be benefit to preservation of parathyroid in situ and its function recovery, thus may reduce the incidence of permanent postoperative hypoparathyroidism.

[Cytology of basaloid squamous cell carcinoma and small cell carcinoma of lung: a comparative study].

OBJECTIVE: To evaluate the roles of cytomorphology and immunohistochemistry in distinguishing between basaloid squamous cell carcinoma (BSC) and small cell carcinoma (SCC) of lung. METHODS: The direct smears and/or liquid-based cytology preparation (ThinPrep) of bronchial brushing/washing and fine-needle aspiration (FNA) specimens from 17 cases of biopsy-proven BSC of lung were retrospectively reviewed and compared with those from 17 cases of SCC. The cytomorphologic parameters analyzed included proportion of cohesive cell clusters, cell palisades/rosettes, adenoid cystic features, crushing artifact, nuclear maximum diameter, nuclear molding, scantiness of cytoplasm,"salt-and-pepper"nuclei, distinct nucleoli, spindly configuration, individual cell keratinization, necrosis, hyaline material, apoptosis and mitotic activity. Immunocytochemical/immunohistochemical study of 25 cases was performed. Ten FNA samples of basaloid squamous cell carcinoma were also analyzed for epidermal growth factor receptor mutations in exons 18, 19, 20 and 21 using amplification refractory mutation system. RESULTS: Most of the 17 BSC cases (15/17) showed a predominance of tightly cohesive tumor cell clusters. The proportion of isolated tumor cells was high in SCC (more than 60% in 14 cases). The nuclear maximum diameter of BSC was slightly larger than that of SCC (9 to 11 µm in BSC versus 7 to 9 µm in SCC)."Salt-in-pepper"nuclei, nuclear molding and crushing artifact were detected in all SCC cases (15/17, 17/17 and 14/17, respectively). These features were only occasionally found in BSC group. Nucleoli were present in BSC and rarely (2/17) in SCC. Only 9 of 17 BSC cases showed individual cell keratinization. The differences in the above-mentioned cytomorphologic features were statistically significance (P<0.05). The results of immunohistochemistry performed on the cell block sections and immunocytochemistry performed on the ThinPrep slides were identical to that performed on the corresponding biopsy specimens. The tumor cells in BSC were consistently positive for CK5, p40 and p63. TTF1, chromogranin A, synaptophysin and CD56 were positive in most of SCC. One of SCC cases showed focal PAX5 expression. No EGFR mutations were detected in the 10 BSC cases studied. CONCLUSIONS: Selected cytomorphologic features, including presence of cohesive cell clusters, larger nuclear size, distinct nucleoli, lack of crushing artifact, absence of nuclear molding and presence of individual cell keratinization, are helpful in diagnosing BSC on cytology specimens. Immunohistochemistry using a panel of TTF1, CK5, p40/p63 and chromogranin A/synaptophysin/CD56 provides further clues in differential diagnosis between BSC and SCC. EGFR mutation study is often negative in lung BSC.

Characterization of a multifunctional methyltransferase from the orchid Vanilla planifolia.

The final enzymatic step in the synthesis of the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) is believed to be methylation of 3,4-dihydroxybenzaldehyde. We have isolated and functionally characterized a cDNA that encodes a multifunctional methyltransferase from Vanilla planifolia tissue cultures that can catalyze the conversion of 3,4-dihydroxybenzaldehyde to vanillin, although 3,4-dihydroxybenzaldehyde is not the preferred substrate. The higher catalytic efficiency of the purified recombinant enzyme with the substrates caffeoyl aldehyde and 5-OH-coniferaldehyde, and its tissue distribution, suggest this methyltransferase may primarily function in lignin biosynthesis. However, since the enzyme characterized here does have 3,4-dihydroxybenzaldehyde-O-methyltransferase activity, it may be useful in engineering strategies for the synthesis of natural vanillin from alternate sources.

Expression of pokeweed antiviral proteins in creeping bentgrass.

Fungal diseases of creeping bentgrass, an important amenity grass used extensively on golf courses, are a serious problem in golf course management. Transgenic approaches to improving disease resistance to fungal diseases are being explored in many species, and in some cases ribosome-inactivating proteins have been found to be effective. We have generated transgenic creeping bentgrass plants expressing three forms of ribosome-inactivating proteins from pokeweed, which are termed pokeweed antiviral proteins (PAP). PAP-Y and PAP-C are nontoxic mutants of PAP; PAPII is the native form of another ribosome-inactivating protein from pokeweed. In creeping bentgrass, PAP-C transformants did not accumulate the protein, suggesting that it is unstable, and in a field test these plants were not protected from infection by the fungal pathogen Sclerotinia homoeocarpa, the causal agent of dollar spot disease. PAPII transformants could accumulate stable levels of the protein but had symptoms of toxicity; one low-expressing line exhibited good disease resistance. PAP-Y transformants accumulated stable levels of protein, and under greenhouse conditions they appeared to be phenotypically normal.

DNA methylation in specific cells of rat liver by N-nitrosodimethylamine and N-nitrosomethylbenzylamine.

Dose-response curves for the O6-methylation of guanine in the hepatic DNA of Wistar and Sprague-Dawley rats were determined after administration of N-nitrosomethylbenzylamine (NMBzA) or N-nitrosodimethylamine (NDMA). Similar results were obtained for both rat strains but methylation of hepatic DNA by NDMA was approximately 9-fold more efficient than with NMBzA when doses were compared on a molar basis. Comparison by immunohistochemical analysis of the distribution of nuclei containing O6-methylguanine within the liver lobules showed that both agents tended to alkylate cells close to the central veins at the lower doses. With increasing doses, the band width of alkylated cells around the central vein increased, spreading in the case of NDMA virtually into the portal zones, whereas with NMBzA the zone of alkylated nuclei reached little more than halfway from the central vein to the portal zone. These differences in the distribution of alkylated cells may explain the differing hepatic responses to these two nitrosamines.