Studies on the human blood group P system: an existence of UDP-Gal:lactosylceramide alpha 1----4 galactosyltransferase in the small p type cells

Human red blood cells and other tissues with the rare small p type lack all P antigens, and are assumed to be missing key glycosyltransferases in the synthetic pathway of P antigens. Galactosyltransferase activities of the P1 and small p cell extracts were measured using lactosylceramide and GlcNAc as galactose acceptors. The two transferase activities of the small p lymphoblastoid cell extract were comparable to that of the P1 cell extract. The anomeric configuration of the galactosylated lactosylceramide was established by digestion with alpha- and beta-galactosidases, by identification of methylated products, and by staining with the monoclonal antibody against globotriaosyl ceramide (Pk antigen). The results indicate that UDP-Gal:LacCer alpha 1----4 Gal transferase, which produces the Pk antigen from the precursor LacCer, exists in the small p cells. However, intact small p cells could not produce the Pk antigen, and, instead, LacCer was accumulated in the cells. The Pk enzyme appears to be not functional in the small p cells in vivo.

Quasi-elastic light scattering from migrating chemotactic bands of Escherichia coli. III. Studies of band formation propagation and motility in oxygen and serine substrates

A series of light scattering experiments have been performed to study both macroscopic aspects of band formation and propagation and microscopic motility parameters of Escherichia coli in the combined substrate gradients of oxygen and serine. From the band formation experiment the conclusion is drawn that a minimum threshold gradient of the substrate is required for bacteria to form a band. From the band propagation experiment in the serine substrate the motility coefficient mu and chemotactic coefficient delta are determined. A separate quasi-elastic scattering experiment has been made with a propagating band to obtain three microscopic motility parameters: mean twiddle time tau 1, mean run time tau 2, and mean run speed V2. Finally, a scaling argument is made to connect the macroscopic parameters mu and delta with the microscopic parameters tau 1, tau 2, and V2, thus achieving a unified understanding of macroscopic and microscopic aspect of chemotaxis.

Human liver fatty acid binding protein gene is located on chromosome 2

The human gene for liver fatty acid binding protein was assigned to chromosome 2 using human-rodent somatic cell hybrids and Southern filter hybridization of cell hybrid DNA. The filters were hybridized to a radiolabeled cloned cDNA which covers 485 bases. Hybridization of the DNA to a human-specific 7.5-kb DNA fragment in HindIII-digested DNA was used to identify the human liver fatty acid binding protein gene. Results from two cell hybrids with chromosomal rearrangements suggest that the gene is on the short arm of chromosome 2.

Effects of arsenate and ergot alkaloid compounds on prostacyclin synthesis in human umbilical endothelium

Cultured human umbilical endothelium was incubated with various concentrations of o-arsenilic acid and ergotamine tartrate respectively for 72 hr at 37 degrees C, 5% CO2/95% air in 100% humidity. At the end of incubation, medium was removed for the determination of 6-keto-PGF1 alpha concentration by RIA method. Compared to the normal controls, arsenate (0.1 to 10.0uM) showed inhibition (17 to 24%) on the PGI2 production. Ergotamine tartrate gave an activatory effect (20 to 12%) in low concentration (0.1 to 1.0uM) incubation, but had inhibitory effect (25%) on the PGI2 production in higher concentration incubation (10.0uM). These results indicate arsenate in low and high concentrations does not play an important role on prostacyclin synthesis in human umbilical endothelium. However, ergotamine tartrate at higher concentration might be a main factor for the lower prostacyclin synthesis in Blackfoot disease, an endemic disease of the peripheral vascular system found in the southwest coast of Taiwan.

A new synthetic route to 2- and 4-methoxyestradiols by nucleophilic substitution

A new snythetic route to 2- and 4-methoxyestradiols is described. Benzo-15-crown-5 with CuI catalyzes the specific nucleophilic substitution at the carbon atom carrying a non-activated halogen on ring A of the estradiol.

An intragenic deletion of the factor IX gene in a family with hemophilia B

A family of seven patients severely afflicted with hemophilia B has been studied for their factor IX genes through the use of factor IX cDNA and genomic DNA probes. The patients had detectable (less than 10% of normal) factor IX antigen in urine and no detectable inhibitors in sera to factor IX protein. Based on the DNA hybridization analysis, these patients showed a partial intragenic deletion in their factor IX gene. The deletion included two exons (exons V and VI) coding for the amino acid sequence from number 85 to 195 of the factor IX protein. The deleted portion of the gene contained the entire factor IX activation peptide. The length of the deletion was estimated to be 10 +/- 0.3 kilobase pairs. This specific gene has been named FIXSeattle. In this family both the deletion and a Taq 1 restriction fragment length polymorphism can be used as a useful marker for accurate detection of female carriers of the deficient factor IX gene.

The human apolipoprotein B-100 gene: a highly polymorphic gene that maps to the short arm of chromosome 2

Using a cloned cDNA of apolipoprotein B-100 as hydridization probe, we have found high frequence polymorphisms in the apoB-100 gene involving sites for the restriction enzymes EcoRI, BamHI, and HindIII. The major EcoRI polymorphisms involved a 17 kb vs 15 kb variant. The incidence of the various phenotypes was estimated. In addition, other complex polymorphisms involving MspI and TaqI sites were also noted. [32P]-labeled apoB-100 cDNA was used as a probe in chromosome mapping studies to detect the human apoB-100 structural gene sequence in human-Chinese hamster and human-mouse cell hybrids. Southern blot analysis of 14 hybrids localized the gene to the short arm of human chromosome 2.

Molecular cloning and expression of partial cDNAs and deduced amino acid sequence of a carboxyl-terminal fragment of human apolipoprotein B-100

Apolipoprotein (apo) B-100 cDNAs were identified in a human liver cDNA library cloned in the expression vector lambda gt11. The beta-galactosidase-apoB-100 fusion protein was detected by two independently produced low density lipoprotein polyclonal antisera and by three apoB-100 monoclonal antibodies that crossreact with apoB-74. It was not recognized by two apoB-100 monoclonal antibodies that crossreact with apoB-26. The longest clone, lambda B8, was completely sequenced. It contains a 2.8-kilobase DNA fragment containing the codons for the carboxyl-terminal 836 amino acid residues of apo-B-100, as well as the 3' untranslated region of apoB-100 mRNA. We have thus mapped apoB-74 to the carboxyl-terminal portion of apoB-100. The deduced amino acid sequence of the cloned DNA matches the sequences of 14 apoB-100 peptides determined in our laboratory. Minor differences in amino acid sequence were noted in three of the peptides, suggesting polymorphism of apoB-100 at the protein and DNA levels. Secondary structure predictions reveal an unusual pattern for apolipoproteins, consisting of beta-structure (24%), alpha-helical content (33%), and random structure (30%). Ten amphipathic helical regions of 10-24 residues were identified. This carboxyl-terminal fragment of apoB-100 is considerably more hydrophobic than other apolipoproteins with known structure. Its lipid binding regions might include stretches of highly hydrophobic beta-sheets as well as amphipathic helices. Our findings on apoB structure might be important for understanding the role of apoB-100-containing lipoproteins in atherosclerosis.

Leucocyte glucose-6-phosphate dehydrogenase (G-6-PD) activity in G-6-PD deficient Chinese

The activity of glucose-6-phosphate dehydrogenase (G-6-PD) in leucocytes was studied for erythrocyte G-6-PD deficiency using 49 hemizygous males, 16 heterozygous females, and 19 normal controls. The mean G-6-PD activity in leucocytes of the affected neonates (9.2 +/- 5.4 units) and the children (11.2 +/- 5.3 units) were significantly lower than those of normal newborns (22.9 +/- 5.1 units, P less than 0.01). Seventy percent of the effected newborns and 58% of the children with G-6-PD deficiency had the leucocyte enzyme activity of less than 13 IU/10(9)WBC. The leucocyte enzyme activity (14.6 +/- 8.6 units) of 16 heterozygous G-6-PD deficient mothers was also lower than that of normal controls (23.1 +/- 7.0 units). The present study thus concludes that, in G-6-PD deficient Chinese, the enzyme defect is demonstrable not only in erythrocytes but also in leucocytes.

Quasi-static electric-field-enhanced diffraction effects in a nematic liquid-crystal film

A quasi-static electric field can enhance laser-induced diffraction rings from a nematic liquid-crystal film. This phenomenon is shown to be the combined result of the critical behavior of the sample at the Freedericksz transition and the nonlinear coupling of the optical and quasi-static electric fields.

Inadequacy of immunoglobulin M hepatitis B core antibody in detecting acute hepatitis B virus infection in infants of HBsAg carrier mothers

To study the usefulness of IgM hepatitis B core antibody (anti-HBc IgM) for detecting hepatitis B virus infections in infants of hepatitis B surface antigen (HBsAg) carrier mothers, serial serum samples from 86 infants of carrier mothers were tested for anti-HBc IgM with a highly specific enzyme immunoassay. Asymptomatic hepatitis B infection occurred frequently in infants under 12 mo of age. Anti-HBc IgM never became positive in 25 infants infected under 9 mo old. It was positive in only 1 of 6 infected at 9 mo and 4 of 13 infected at 12 mo of age. The IgM antibody lasted for less than 6 mo. Although the infection was delayed in 28 infants receiving hepatitis B immune globulin, the poor anti-HBc IgM response did not seem to be due to the immune prophylaxis. Our study clearly indicates the limitation of anti-HBc IgM for detecting acute hepatitis B infection in infants born to HBsAg carrier mothers.