朗斯:科技创新是企业的支点

在美容业风起云涌的冲浪者中总有这样一些“异类”，他们没有大肆叫嚣着奔跑冲刺，而是默默而从容地前进，每一步都在地上留下一个坚实的脚印。转眼间，无数人被大浪吞没，退潮时，沉入沙底的金子才慢慢闪现出光芒。朗斯国际就是其中之一。[编者按]     

The role of alkaloids in Ipomoea carnea toxicosis: A study in rats

Ipomoea carnea promotes in livestock a toxicosis histologically characterized by vacuolated cells in different organs. The toxic principles of I. carnea are the alkaloids swainsonine and calystegines B1, B2, B3 and Cl. However, it has not been determined whether the effects observed in rats treated with this plant are only due to swainsonine or if the calystegines have some additive toxic effect. Thus, the aim of the present study was to evaluate in rats the toxic effects of the L carnea aqueous fraction (AF) and of its different alkaloids when administered individually at the same concentration as in this fraction, for 14 days. No anorexic effect and/or alteration in body weight was observed in any group. The histopathologic study showed that while calystegines did not produce any toxic effects, swainsonine and I carnea AF promoted vacuolation in different organs, being more severe in the animals from the I. carnea AF group and extensible to other organs evaluated. No alterations were detected in the central nervous system of rats of any group assayed. The results obtained here suggest that calystegines may act as coadjuvants of swainsonine in I carnea toxicosis; however, little can be proposed about the neurotoxic effect of I. carnea since rats did not prove to be a good model for the reproduction of neuronal storage disease.     

Dilemmas of focus group recruitment and implementation: a pilot perspective

In this paper, Isis Lioba Howatson-Jones reviews some of the dilemmas experienced in arranging focus groups, particularly for the novice researcher and draws upon a pilot research project on qualified nurses' learning as illustration. The paper explores ways of overcoming recruitment and method issues during the pilot phase of a study, and presents a number of recommendations for the practice and conduct of focus groups.     

Expression of angiogenic factors in placenta of stressed rats

The aim of the present study was to analyse the influence of stress on pregnant rats, particularly in terms of maternal, placental and fetal weight, placental morphology and placental gene expression of the angiogenic factors Vegfa and Pgf and their receptors. The parameters were evaluated on gestation Day 20. Maternal, fetal and placental weights were statistically lower in stressed animals than controls, suggesting abnormalities in gestational physiology. Morphologically the placentas of rats subjected to stress were reduced in size and weight, with few glycogen cells and a significant increase in the number of apoptotic cells. Stress caused an increase in placental gene expression of Vegfa (P<0.05) and a reduction in Pgf, Flt1 and Kdr expression (P<0.05). It has been suggested that increased VEGF is associated with vasodilatation and hypotension, but in this model persistent hypertension was present. This study suggests that the limited hypotensive Vegfa response to stress-induced hypertension could result from reduced expression of Flt1/Kdr disrupting specific VEGF pathways. These findings may elucidate one of the multiple possible factors underlying how stress modulates placental physiology, and could aid the understanding of stress-induced gestational disorders.     

A pooled analysis of the outcome of prospective colonoscopic surveillance for familial colorectal cancer

Surveillance guidelines for the management of familial colorectal cancer (FCC), a dominant family history of colorectal cancer in which the polyposis syndromes and Lynch syndrome have been excluded, are not firmly established. The outcome of colonoscopic surveillance is studied using data from six centers. DNA mismatch repair deficiency was excluded by genetic testing. Families were classified as FCC type X if they fulfilled the original Amsterdam criteria (AC) and late onset (LOFCC) if they fulfilled the AC apart from not having a cancer aged under 50. The most advanced findings on colonoscopy were analyzed. One thousand five hundred eighty‐five individuals (median age 47.3, 44% male) from 530 FCC families (349 FCC type X) underwent a total of 4,992 colonoscopies with 7,904 patient‐years of follow‐up. Results for FCC type X and LOFCC were very similar. At baseline, 22 prevalent asymptomatic colorectal cancers were diagnosed, 120 (7.6%) individuals had high‐risk adenomas and 225 (14.2%) simple adenomas. One thousand eighty‐eight individuals had a further colonoscopy (median follow‐up of 6.2 years). Of nine individuals diagnosed with cancer, eight had a previous history of at least one polyp/adenoma. High‐risk adenomas were detected in 92 (8.7%) and multiple adenomas were detected in 20 (1.9%) individuals. Both FCC type X and LOFCC have a high prevalence of colorectal cancers and on follow‐up develop high‐risk adenomas (including multiple adenomas), but infrequent interval cancers. They should be managed similarly with five‐yearly colonoscopies undertaken from between 30 and 40 with more intensive surveillance in individuals developing multiple or high‐risk adenomas.     

MTHFR 677C→T And 1298A→C POLYMORPHISMS IN CHILDREN WITH DOWN SYNDROME AND ACUTE MYELOID LEUKEMIA IN BRAZIL

Down syndrome (DS) is an important risk factor associated with acute leukemia (AL). The presence of polymorphisms that reduce 5,10-methylenetetrahydrofolate reductase (MTHFR) activity has been linked to the multifactorial leukemogenic process. The authors have conducted a study to test whether 677C→T and/or 1298A→C polymorphisms of MTHFR would play an additional role in susceptibility of acute myeloid leukemia (AML) in DS children. They also verified whether any polymorphism in the MTHFR gene was associated with the risk of DS. Genetic polymorphisms determination was carried out in 248 samples from healthy individuals as controls and a total of 115 DS children (65 without leukemia and 50 with AML). The present study failed to reveal any association between these polymorphisms and risk of AML in DS children. The data also indicate that MTHFR polymorphisms are not associated with risk of being a DS child.