Characterization of the specificities of human blood group H gene-specified alpha 1,2-L-fucosyltransferase toward sulfated/sialylated/fucosylated acceptors: evidence for an inverse relationship between alpha 1,2-L-fucosylation of Gal and alpha 1,6-L-fucosylation of asparagine-linked GlcNAc

The assembly of complex structures bearing the H determinant was examined by characterizing the specificities of a cloned blood group H gene-specified alpha 1,2-L-fucosyltransferase (FT) toward a variety of sulfated, sialylated, or fucosylated Gal beta 1,3/4GlcNAc beta- or Gal beta 1,3GalNAc alpha-based acceptor structures. (a) As compared to the basic type 2, Gal beta 1,4GlcNAc beta-(K(m) = 1.67 mM), the basic type 1 was 137% active (K(m) = 0.83 mM). (b) On C-6 sulfation of Gal, type 1 became 142.1% active and type 2 became 223.0% active (K(m) = 0.45 mM). (c) On C-6 sulfation of GlcNAc, type 2 showed 33.7% activity. (d) On C-3 or C-4 fucosylation of GlcNAc, both types 1 and 2 lost activity. (e) Type 1 showed 70.8% and 5.8% activity, respectively, on C-6 and C-4 O-methylation of GlcNAc. (f) Type 1 retained 18.8% activity on alpha 2,6-sialylation of GlcNAc. (g) Terminal type 1 or 2 of extended chain had lower activity. (h) With Gal in place of GlcNAc in type 1, the activity became 43.2%. (i) Compounds with terminal alpha 1,3-linked Gal were inactive. (j) Gal beta 1,3GalNAc alpha- (the T-hapten) was approximately 0.4-fold as active as Gal beta 1,4GlcNAc beta-. (k) C-6 sulfation of Gal on the T-hapten did not affect the acceptor activity. (l) C-6 sulfation of GalNAc decreased the activity to 70%, whereas on C-6 sulfation of both Gal and GalNAc the T-hapten lost the acceptor ability. (m) C-6 sialylation of GalNAc also led to inactivity. (n) beta 1,6 branching from GalNAc of the T-hapten by a GlcNAc residue or by units such as Gal beta 1, 4GlcNAc-, Gal beta 1,4(Fuc alpha 1,3)GlcNAc-, or 3-sulfoGal beta 1,4GlcNAc- resulted in 111.9%, 282.8%, 48.3%, and 75.3% activities, respectively. (o) The enhancement of enzyme affinity by a sulfo group on C-6 of Gal was demonstrated by an increase (approximately 5-fold) in the K(m) for Gal beta 1,4GlcNAc beta 1,6(Gal beta 1,3)GalNAc alpha-O-Bn in presence of 6-sulfoGal beta 1,- 4GlcNAc beta-O-Me (3.0 mM). (p) Among the two sites in Gal beta 1, 4GlcNAc beta 1,6(Gal beta 1,3) GalNAc alpha-O-Bn, the enzyme had a higher affinity ( > 3-fold) for the Gal linked to GlcNAc. (q) With respect to Gal beta 1,- 3GlcNAc beta-O-Bn (3.0 mM), fetuin triantennary asialo glycopeptide (2.4 mM), bovine IgG diantennary glycopeptide (2.8 mM), asialo Cowper's gland mucin (0.06 mM), and the acrylamide copolymers (0.125 mM each) containing Gal beta 1,3GlcNAc beta-, Gal beta 1,3(6-sulfo)GlcNAc beta-, Gal beta 1,3GalNAc alpha-, Gal beta 1,3Gal beta-, or Gal alpha 1,3Gal beta- units were 153.6%, 43.0%, 6.2%, 52.5%, 94.9%, 14.7%, 23.6%, and 15.6% active, respectively. (r) Fucosylation by alpha 1,2-L-FT of the galactosyl residue which occurs on the antennary structure of the bovine IgG glycopeptide was adversely affected by the presence of an alpha 1,6-L-fucosyl residue located on the distant glucosaminyl residue that is directly attached to the asparagine of the protein backbone. This became evident from the 4-fold activity of alpha 1,2-L-FT toward bovine IgG glycopeptide after approximately 5% removal of alpha 1,6-linked Fuo.     

Experimental and numerical investigation of warpage of semicrystalline polymers in rotational molding

Warpage of various semicrystalline polyethylenes (linear low density polyethylene [LLDPE]) has been investigated under typical rotational molding conditions, which means slow cooling from only one side. We have developed an experimental technique that is able to quickly rate different materials with respect to warpage under typical process conditions. We have also developed a numerical model simulating the experiments assuming a thermoelastic material including crystallization. As has been observed in practical rotational molding, it has been found in both experiments and simulations that materials with high crystallinity have in general higher warpage. The simulations also showed that the crystallization kinetics has implications on the warpage because the crystallinity gradient during solidification depends on the rate of crystallization. POLYM. ENG. SCI., 45:945–952, 2005. © 2005 Society of Plastics Engineers     

Evolutionary variants of the human immunodeficiency virus type 1 V3 region characterized by using a heteroduplex tracking assay

Syncytium-inducing (SI) variants of human immunodeficiency virus type 1 (HIV-1) are evolutionary variants that are associated with rapid CD4+ cell loss and rapid disease progression. The heteroduplex tracking assay (HTA) was used to detect evolutionary V3 variants by amplifying the V3 sequences from viral RNA derived from 50 samples of patient plasma. For this V3-specific HTA (V3-HTA), heteroduplexes were formed between the patient V3 sequences and a probe with the subtype B consensus V3 sequence. Evolution was then measured by divergence from the consensus. The presence of evolutionary variants was correlated with SI detection data on the same samples from the MT-2 cell culture assay. Evolutionary variants were correlated with the SI phenotype in 88% of the samples, and 96% of the SI samples contained evolutionary variants. In most cases the evolutionary V3 variants represented discrete clonal outgrowths of virus. Sequence analysis of the six discordant samples that did not show this correlation indicated that three non-syncytium-inducing (NSI) samples had V3 sequences that had evolved away from the consensus sequence but not toward an SI genotype. A fourth sample showed little evolution away from the consensus but was SI, which indicates that not all SI variants require basic substitutions in V3. The other two samples had SI-like genotypes and NSI phenotypes, suggesting that V3-HTA was able to detect SI emergence in these samples in the absence of their detection in vitro. V3-HTA was also used to confirm SI variant selection in MT-2 cells and to examine the possibility of variant selection during virus culture in peripheral blood cells.     

Determination of volterra transfer functions of non-linear multiport networks

A method is presented to determine frequency domain Volterra transfer functions of non-linear multiport networks containing non-linear multiport subsystems (elements). the method is based on an extension of the probing method to allow arbitrary (also commensurate) frequencies. A recursively based algorithm for the determination of Volterra transfer functions of non-linear multiport networks is derived. A computer implementation of the method in a symbolic programming language is presented. This makes it possible to determine algebraic expressions of the Volterra transfer functions. Three examples are considered.     

The domain of function: who''s got it? Who''s competing for it?

We report on two patients with sulbactam/ampicillin (SBT/ABPC)-induced pneumonitis. Both patients were being treated with SBT/ABPC for respiratory-tract infections. Following the initiation of SBT/ABPC chemotherapy, however, chest X-ray films showed a shift of shadow in patient 1 and new pulmonary infiltration shadows in patient 2. Bronchoalveolar lavage fluid (BALF) findings showed a marked increase in the total cell count and percentage of eosinophils in patient 1 and of lymphocytes in patient 2. The results of lymphocyte stimulation tests were SBT/ABPC positive for both patients. SBT/ABPC therapy was therefore discontinued and corticosteroid therapy started. Both patients were subsequently relieved of their symptoms demonstrated significantly lower and pulmonary infiltrate levels. Based on these findings, both patients were given a diagnosis of SBT/ABPC-induced pneumonitis. It has been widely reported that CD 4/CD 8 ratio in BALF decreases in cases of drug-induced pneumonitis. However, some reports have cited increase in the CD 4/CD 8 ratio. In our two patients as well, the CD 4/CD 8 ratio increased. These results, together with the findings from several other case reports, indicate that the CD 4/CD 8 ratio may not be good basis for diagnosing drug-induced pneumonitis. Recently, the incidence of drug-induced pneumonitis has been rising. To our knowledge this is the first report documenting cases of SBT/ABPC-induced pneumonitis.     

Health and education: alternative courses for the development of nursing personnel

The disposition behavior of trientine, a selective copper-chelating drug for Wilson's disease, and its metabolites in normal patients with Wilson's disease and rats were studied. A high concentration of metabolites appeared in blood samples of patients and rats in the early stage after administration of trientine. Furthermore, large amount of trientine metabolites were excreted into the urine of patients. These results suggest that trientine is remarkably subjected to a first-pass effect. The drug concentration area under the curve (AUC) of the unchanged form and the metabolites of trientine in patients was not dependent on the administered dosage. It seems that the absorption process is an important factor for the disposition behavior of trientine, we have also investigated the uptake characteristics of trientine by rat intestinal brush-border membrane vesicles. The uptake characteristics of trientine were similar to the physiological polyamines, spermine and spermidine. The uptake rate of trientine was dose-dependently inhibited by spermine and spermidine. Moreover, spermine competitively inhibited the uptake of trientine with a Ki value of 18.6 muM. This value is very close to the Km value for spermine (30.4 muM). These data suggested that the uptake mechanism of trientine in rat small intestinal brush-border membrane vesicles was almost identical to that of spermine and spermidine, and that the physiological polyamines seem to have the ability to inhibit the absorption of trientine from the gastrointestinal tract.