Search

Contains fulltext : 273921.pdf (Publisher’s version ) (Open Access) BACKGROUND: T4-classified squamous cell carcinoma (SCC) of external auditory canal (EAC) can potentially involve different anatomical structures, which could translate into different treatment strategies and survival outcomes within one classification. Our aim is to evaluate the clinical added value of T4-subclasses proposed by Lavieille and by Zanoletti. METHODS: Retrospective data, including patients with primary operated cT4-classified EAC SCC, was obtained from 12 international hospitals. We subclassified according to the T4-subclasses. The treatment strategies, disease-free survival (DFS) and overall survival per subclass were calculated. RESULTS: A total of 130 T4-classified EAC SCC were included. We found commonly used treatment strategies per subclass according to Lavieille and the DFS seems also to differ per subclass. Subclass according to Zanoletti showed comparable treatment strategies and survival outcomes per subclass. CONCLUSION: Our study suggests that the subclass according Lavieille might have added value in clinical practice to improve care of T4-classified EAC SCC.

Total syntheses of the GlyCAM-1 (glycosylation-dependent cell adhesion molecule-1) oligosaccharide structures: [alpha-NeuAc-(2 --> 3)-beta-Gal-(1 --> 4)-[alpha-Fuc-(1 --> 3)]-beta-(6-O-SO3Na)-GlcNAc-(1 --> 6)]-[alpha-NeuAc-(2 --> 3)-beta-Gal-(1 --> 3)]-alpha-GalNAc-OMe (1) and [alpha-NeuAc-(2 --> 3)-beta-Gal-(1 --> 4)-[alpha-Fuc-(1 --> 3)]-beta-GlcNAc-(1 --> 6)]-[alpha-NeuAc-(2 3)-beta-Gal-(1 --> 3)]-alpha-GalNAc-OMe (2) through a novel sialyl LewisX tetrasaccharide donor are described. Employing sequential glycosylation strategy, the starting trisaccharide was regio- and stereoselectively constructed through coupling of a disaccharide imidate with the monosaccharide acceptor phenyl-6-O-naphthylmethyl-2-deoxy-2-phthalimido-1-thio-beta-D-glucopyranoside with TMSOTf as a catalyst without affecting the SPh group. The novel sialyl Lewisx tetrasaccharide donor 3 was then obtained by alpha-L-fucosylation of trisaccharide acceptor with the 2,3,4-tri-O-benzyl-1-thio-beta-L-fucoside donor. The structure of the novel sialyl Lewisx tetrasaccharide was established by a combination of 2D DQF-COSY and 2D ROESY experiments. Target oligosaccharides 1 and 2 were eventually constructed through heptasaccharide which was obtained by regioselective assembly of advanced sialyl Lewisx tetrasaccharide donor 3 and a sialylated trisaccharide acceptor in a predictable and controlled manner. Finally, target heptasaccharides 1 and 2 were fully characterized by 2D DQF-COSY, 2D ROESY, HSQC, HMBC experiments and FAB mass spectroscopy.

The total syntheses of several complex oligosaccharide moieties that occur in the core structure of sulfated mucins are reported. A trisaccharide acceptor was obtained through regio- and stereoselective sialylation of methyl (6-O-pivaloyl-beta-D-galactopyanosyl)(1-->3)-4,6-O-benzylidene-2-a cetamido-2-deoxy-alpha-D-galactopyranoside with a novel sialyl donor. A tetrasaccharide, pentasaccharide, and hexasaccharide were constructed in predictable and controlled manner with high regio- and stereoselectivity after the successful preparation and employment of a disaccharide donor, trisaccharide donor, disaccharide acceptor, and trisaccharide acceptor building blocks. Finally, a mild oxidative cleaving method was adopted for the selective removal of 2-naphthylmethyl (NAP) in the presence of benzyl groups.

The 2-naphthylmethyl (NAP) group is a versatile group for protection of hydroxyl functions. It is stable to 4% TFA in CHCl 3 , hot 80% HOAc–H 2 O, SnCl 2 –AgOTf and HCl–EtOH, but it can readily be removed with DDQ in CH 2 Cl 2 .

An efficient synthesis of the mucin core-2 analogue 1a Download : Download high-res image (83KB) Download : Download full-size image Figure 1 . This C-2 position is blocked for commonly occurring α(1,2)- l -fucosyltransferase. was accomplished using N-p-nitrobenzyloxycarbonyl(PNZ)-protected trichloroacetimidate 4 Download : Download high-res image (134KB) Download : Download full-size image Scheme 2 . Reagents and conditions: (i) 4 (1.5 equiv), TESOTf (0.24 equiv), CH2Cl2, 4 A molecular sieves, rt, 15 min, 89%; (ii) Na2S2O4 (8 equiv), MeCN:EtOH:H2O (v/v/v 1:1:1), 10 min; (iii) Ac2O–MeOH; (iv) 75% acetic acid, 45 °C, 2 h, 90%; (v) 80% acetic acid, 40 °C, 2 h, 92%; (vi) 4 (1.2 equiv), TESOTf, CH2Cl2, −65 °C, 1 h, 78%; (vii) pyridine–Ac2O, DMAP; (viii) 4 (1.2 equiv), BF3·Et2O (0.5 equiv), CH2Cl2, −60 °C, 30 min, 82%. as a novel glycosyl donor.

The total synthesis of a sialylated and sulfated oligosaccharide 1 representative of a structure occurring in respiratory mucins has been accomplished. Our strategy depends upon the employment of 2-naphthymethyl (NAP) protection for hydroxyl functions. Choice of the well-defined sialyl donor 15 was made because of its enhanced reactivity over the parent compound 14 for glycosylation.

The prevalence of diabetes and obesity were assessed in an age- and sex-stratified sample of 1078 individuals living in Mahé, The Republic of Seychelles. Presence or absence of diabetes mellitus was assessed by measuring glucose concentration in fasting venous blood. Prevalence of obesity (standardized for age) was elevated five-fold in women compared with men (20.9 vs 4.2%). In women, it increased from 8.9% at age 25-34 years to 29.4% at age 35-44 years and plateaued thereafter, whereas it did not change with age in men. Prevalence of diabetes (standardized for age) was 3.4% for men and 4.6% for women. It increased markedly with age, from 0.0 and 0.8% at age 25-34 years to 8.8 and 13.4% at age 55-64 years in men and women, respectively. A strong association of diabetes with excess body weight was observed. Most cases of diabetes can be attributed to Type 2 (non-insulin-dependent) diabetes. Fifty-five percent of diabetic individuals were unaware of their disease at the time of the survey.

The synthesis of an octasaccharide containing the dimeric Lex oligosaccharide structure found in PSGL-1 carbohydrate chains is reported. Several approaches were investigated employing regioselective and stereoselective glycosylation procedures, and a novel Lewisx trisaccharide donor, 7, was prepared and utilized as a key intermediate building block in the scheme developed for the construction of octasaccharide 3. Toward the preparation of 7, investigations into the influence of different protecting groups upon the relative reactivities of disaccharide acceptor moieties, 25 or 26, and the fucosyl donors, 10 and 11, were conducted using similar glycosylating conditions. Dramatic differences were noted between the effects of electron-donating and electron-withdrawing groups upon the reactivity of the acceptor hydroxyl. A similar effect upon the glycosylating capability of the donor molecule was, likewise, observed. The repeat use of donor 7 was instrumental in the synthesis of the desired dimeric octasacchar...

The syntheses of two sulfated pentasaccharides: β- d -Gal6SO 3 Na-(1→3)-[β- d -Gal-(1→4)-α- l -Fuc-(1→3)-β- d -GlcNAc-(1→6)]-α- d -GalNAc→OMe ( 1 ) and β- d -Gal6SO 3 Na-(1→3)-[β- d -Gal-(1→4)-α- l -Fuc-(1→3)-β- d -GlcNAc6SO 3 Na-(1→6)]-α- d -GalNAc→OMe ( 2 ) by using Lewis X trisaccharides 12 and 16 as glycosyl donors are described. Sulfated oligosaccharides 1 – 2 and intermediate compounds are fully characterized by 2D 1 H– 1 H DQF-COSY and 2D ROESY experiments.

"Safety is a scarce resource. To allocate this resource optimally, two basic questions must be answered. What level of safety shoud we be seeking? (How safe should we be?) What is the least costly way of achieving this level? (In what ways can we buy safety most cheaply?)" (Lave 1968, p. 512). These two questions are simple and direct, but, unfortunately, answers to them have proven elusive. Response to the first is contingent on understanding the costs and benefits associated with each attainable level of workplace safety. Answers to the second are obtained by evaluating alternative technologies and public policy options. In recent years, safety standards have been the most frequently advocated method for reducing the level of workplace injuries, illnesses and deaths. Billions of dollars have been expended and thousands of new regulations have been written. In the agricultural sector alone, estimates prepared prior to promulgation of the roll-over protection standards for tractors and the farm machinery guarding standards suggested that first year costs of these combined standards equaled about 20% of the total annual agricultural wage bill (U.S. Department of Labor 1974). The regulatory approach, as embodied in the Occupational Safety and Health Act of 1970 is but one of five possible approaches to address the goals of workplace accident reduction. The others include: (a) the competitive market approach (i.e. setting wage differentials to compensate workers for higher levels of risk); (b) resorting to the judicial process for assignment of fault and awarding of compensatory judgments; (c) allocating the risk and compensatory payments through the insurance industry; and (d) the use of educational and informational institutions to distribute results of safety research efforts to workers, employers and self-employed entrepreneurs. It is the opinion of the authors that an optimal solution to the two questions posed at the beginning of this paper will come about only as a result of an integration of these five approaches. To foster discussion of this desired goal the present paper is designed to: (a) provide a cursory examination of workplace accident causal factors; (b) define the nature of each policy alternative which impacts on the level of workplace safety; (c) describe the application of each policy to the agricultural sector; and (d) identify the research required to move in the direction of providing policy responses to the twin questions of "how much" and "at what cost?"

THERE HAS long been a need for more detailed investigations of all phases of embryology, as there are serious gaps in the literature. Most papers in the field either report studies of the very early sequences of cell division, or they describe the events leading up to fertilization and may also include some early embryonic stages. Only a few describe in detail the origin and development of meristems, tissues, and organs as they arise in ontogeny. This study aims to describe the ontogeny of a dicotyledonous embryo, that of the McIntosh apple, by determining the number, kind, and sequence of events and their possible interrelationships. Such a study should lead to a clearer understanding of the anatomy of the mature plant, since it provides a basis for further studies of factors which operate to bring about the organization of the mature plant. The McIntosh apple was chosen for study because it is readily available and is a dicotyledon of considerable economic importance about which a great deal already is known. This study started out to be a detailed description of the sequence of cell divisions which produce the embryo, but the embryos do not grow by a single sequence of predetermined cell divisions. The embryo as a whole goes through a sequence of growth periods. In apple four major stages of growth occur: (1) the embryo grows as a filament; (2) the embryo tends to grow like a sphere; (3) new centers of growth are established, and primary meristems are initiated, as some of the cells become morphologically altered; and (4) the cotyledonary primordia grow rapidly, as the shoot apex, leaf primordia, and procambia develop. The first three stages are described in this paper. The filamentous stage is divided into two phases. The first begins with the zygote (fig. 1) which without increasing in size is divided by three transverse divisions into four cells (fig. 2, 9, 23-27). In the second phase the embryo increases its size only in length (fig. 3). Transverse divisions divide the em

Durch Kondensation des Bromids (I) mit dem Galaktosid (II) wird das Disaccharid (IIIa) erhalten und uber (IIIb) zur im Titel genannten Verbindung (IIIc) deblockiert.

Aus dem Bromid (I) werden die anomeren Glykoside (IIa) und (IIb) erhalten und nach chromatographischer Trennung zu (IIc) und (IId) deacetyliert.