Elucidating the Fragmentation Mechanism of Protonated Lewis A Trisaccharide using MSn CID

Lewis blood group antigens are a prominent example of isomeric oligosaccharides with biological activity. Understanding the fragmentation mechanism in the gas phase is essential for their identification and assignment by mass spectrometric methods such as ESI-MS. In this work, the [M + H]+ species of Lewis A trisaccharide and Lewis A trisaccharide methyl glycoside were studied by ESI-MS with FT-ICR as mass analyzer with respect to their fragmentation mechanism. The comparison between the underivatized and the methylated species has shown that the reducing end plays a key role in this mechanism. The results of this study question the existence of Z-type fragment ions after activation of the protonated species. The main product of the fragmentation are Y-type fragment ions and a combination of Y-type fragmentation and the loss of water at the reducing end instead of Z-type fragmentation. C-type fragment ions could not be detected. MS3 measurements also reveal that each fragment ion only occurs with the participation of a mobile proton and the possibility of glycosidic bond cleavage after fragmentation has already occurred at the reducing end as B2 fragment ion.

mAb Das-1 recognizes 3’-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal Epithelia

Introduction Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett’s esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive. Methods In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA. Results The epitope recognized by mAb Das-1 is 3’-Sulfo-Lewis A/C (3’-Sulfo-LeA/C). 3’-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation. Discussion 3’-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.

Walter H. Lewis: A Life Spent Pushing Back the Frontiers of Botany (1930–2020)

In memory of Dr. Walter H. Lewis

The Bridge is back!

We are honoured to spend some time talking with Dr. Steph Lewis, a Clinical Research Training Fellow at the Institute of Psychiatry, Psychology and Neuroscience, King's College, London, and Editor of The Bridge, about the exciting new relaunch of ACAMH’s magazine, The Bridge.

Saunders Lewis agus an tionchar a bhí aige ar Mháirtín Ó Cadhain agus ar ghluaiseacht na Gaeilge sna 1960idí

De réir Mháirtín Uí Chadhain, ba é Saunders Lewis an fear liteartha ba mhó cáil sa Bhreatain Bheag sna 1960idí agus ba é an t-údar ba mhó tábhacht ar fad é a bhí ag saothrú a phinn in aon cheann de na teangacha Ceilteacha ag an am. Tá cáil Lewis imithe i bhfad agus i ngearr mar gheall ar an léacht cháiliúil raidió a thug sé uaidh, agus a craoladh ar an BBC, i mí Feabhra 1962. Tynged yr Iaith (Cinniúint na Teanga) ba theideal don léacht iomráiteach sin inar leag sé amach a ghéire is a bhí éigeandáil na teanga sa Bhreatain Bheag ag an am. Chun fuascailt a fháil ar an scéal, mhol sé modhanna úra agóidíochta agus léirsithe chun tathant ar na húdaráis stádas oifigiúil na Breatnaise a threisiú sa saol poiblí. Bhí briathra Lewis ina ndíol spéise do ghluaiseacht na Gaeilge in Éirinn na linne sin, a bhuíochas sin don aistriúchán Gaeilge Bás nó Beatha? a rinne Máirtín Ó Cadhain, agus a d’fhoilsigh Sáirséal agus Dill, in 1963. San aiste seo, déanfar anailís ar aistriúchán sin Uí Chadhain féachaint cén rian a d’fhág teachtaireacht Lewis ar mhodhanna agóidíochta ghluaiseacht na Gaeilge in Éirinn sna 1960idí. Áiteofar gur athraigh Bás nó Beatha? treo agus cur chuige ghníomhaíochas na Gaeilge in Éirinn trí smaointeoireacht Saunders Lewis a chur ar a shúile do chomhluadar ní ba leithne daoine. Breathnófar, go háirithe, ar cén tionchar a bhí ag modhanna léirsithe na Breataine Bige, agus an easumhlaíocht shibhialta go háirithe, ar an eagraíocht Misneach, ar Chonradh na Gaeilge agus ar Ghluaiseacht Chearta Sibhialta na Gaeltachta. Chuige sin, bainfear gaisneas as an dá shaothar le Saunders Lewis a d’aistrigh Ó Cadhain; ba iad sin ‘Aon Teanga don Bhreatain Bheag’, a foilsíodh ar an iris Comhar in 1955, chomh maith le Bás nó Beatha? (1963). Ina theannta sin, cuirfear sampla de scríbhinní polaitiúla Uí Chadhain féin sa mheá, ‘Do na Fíréin’ (1962) agus Gluaiseacht na Gaeilge: Gluaiseacht ar Strae (1970), gan trácht ar an dá dhíolaim aistí Caithfear Éisteacht! (1999) agus Ó Cadhain i bhFeasta (1990).

Perbedaan aliran dalam Islam sebagai konflik hubungan pernikahan dalam perspektif Lewis A. Coser

The topic of the problem in this research is that there are not a few couples whose relationships are in different schools even though they are in the same Islamic religion. This study aims to analyze what conflicts will occur in a marriage relationship with different streams. So, in this study, the researcher wants to use the conflict theory according to Lewis A. Coser as a knife of analysis. The method used in this research is a qualitative approach, namely the process of exploring and understanding the meaning of individual and group behavior, describing social problems or humanitarian problems. Meanwhile, the type of research used is descriptive qualitative. The sample used was 3 married couples with different sects and 2 unmarried couples, but dating people from different sects. The result of this research is that conflicts can occur between partners, such as forcing them to enter into one of the pairs of streams and it can also occur between families such as damage to the relationship between parents and children. Topik Permasalahan dalam penelitian ini adalah tak sedikit jumlah pasangan yang menjalin hubungannya berada dalam perbedaan aliran meskipun dalam agama islam yang sama. Penelitian ini bertujuan untuk menganalisis konflik-konflik apa sajakah yang akan terjadi pada hubungan pernikahan berbeda aliran. Sehingga, dalam penelitian ini peneliti ingin menggunakan teori Konflik menurut Lewis A. Coser sebagai pisau analisisnya. Metode yang digunakan dalam penelitian ini adalah Pendekatan Kualitatif yaitu proses eksplorasi dan memahami makna perilaku individu dan kelompok, menggambarkan masalah sosial atau masalah kemanusiaan. Sedangkan, jenis penelitian yang digunakan adalah kualitatif deskriptif. Sampel yang digunakan adalah 3 orang pasangan yang sudah menikah dengan berbeda aliran dan 2 orang yang belum menikah, namun berpacaran dengan orang yang berbeda aliran. Hasil dari penelitian ini adalah konflik bisa terjadi antar pasangan seperti pemaksaan untuk masuk kedalam salah satu aliran pasangan dan juga bisa terjadi antar keluarga seperti rusaknya hubungan antara orang tua dengan anak.

Infiltração de água no solo em um plantio de melancia no sudeste paraense

Objetivou-se no presente estudo realizar uma análise comparativa do comportamento da infiltração de água no solo em um plantio de melancia (Citrullus lanatus (Thunb.) Matsum & Nakai). A área de estudo localiza-se no Projeto de Assentamento Ipiranga, no sudeste paraense. Na análise de infiltração aplicou-se o delineamento experimental inteiramente casualizado, com a utilização de dois aneis cilindros (25 e 50 cm de diâmetros cada e 30 cm de altura). Os dados de velocidade básica e infiltração de agua no solo foram obtidos in situ e comparados à dois modelos matemáticos empíricos. Os resultados médios de infiltração real obtidos foram 14,1582 cm h-1; 5,4623 cm h-1; 13,3038 cm h-1 e 5,2538 cm h-1, respectivamente. A aplicação dos modelos empíricos elaborados por Kostiakov e Kostiakov-Lewis não representaram valores próximos ao real, porém Kostiakov-Lewis demonstrou melhor desempenho, principalmente em relação à Velocidade de Infiltração Básica (VIB). Concluiu-se a necessidade de rever a aplicação dos modelos de Kostiakov e Kostiakov-Lewis à ensaios de infiltração de água no solo com duração de tempo muito longo, pois os mesmos apresentam desvios não satisfatórios quando comparados ao valor real e sugere-se a aplicação de outros modelos matemáticos empíricos, no entanto o fenômeno observado comparado ao cultivo de melancia apresentou lâminas acumuladas aceitáveis dentro de uma média de produção adequada para a região sudeste paraense.