The extrapituitary prolactin promoter polymorphism is associated with rheumatoid arthritis and anti-CCP antibodies in Mexican population

Prolactin (PRL) is a hormone–cytokine that has been involved in autoimmunity due to its immunoregulatory and lymphoproliferative effects. It is produced by various extrapituitary sites including immune cells, under control of a superdistal promoter that contains a single nucleotide polymorphism − 1149 G/T previously associated with rheumatoid arthritis (RA) susceptibility in European population. The aim of this study was to investigate the association of the extrapituitary PRL − 1149 G/T promoter polymorphism with clinical parameters, clinical activity and disability indices in RA patients from Western Mexico and to analyze the PRL mRNA expression according to the PRL − 1149 G/T promoter polymorphism in total leucocytes from RA patients and controls. We conducted a case–control study that included 258 RA patients and 333 control subjects (CS). The DNA samples were genotyped using the PCR–RFLP method and the PRL mRNA expression was determined by quantitative real time PCR. PRL serum levels and antibodies to cyclic citrullinated peptides (anti-CCP) were measured with ELISA. We found significant differences in the genotype (p = 0.022) and allelic (p = 0.046) distribution of the polymorphism between RA patients and control subjects. According to the dominant genetic model, there is an association between the T allele (GT + TT genotypes) and decreased RA susceptibility in comparison to the G allele carriers (GG genotype) (OR 0.64, 95% CI 0.45–0.92; p = 0.011). The T allele carriers (GT + TT genotypes) had lower titers of anti-CCP antibodies in comparison to the G allele carriers (GG genotype) (median, 66 U/mL vs. 125 U/mL; p = 0.03). Furthermore, the GG homozygotes had higher PRL mRNA expression in comparison to the GT heterozygotes, and this latter with respect to the TT homozygotes, in both groups (RA: 1 > 0.72 > 0.19; CS: 1 > 0.54 > 0.28). However, PRL serum levels were similar in both groups. Our results suggest that the PRL − 1149 T allele is a genetic marker for decreased RA susceptibility and is associated with lower titers of anti-CCP antibodies in Mexican population. We also suggest influence of genotype upon PRL mRNA expression.     

The 65-kDa phorbol-diester hydrolase in mouse plasma is esterase 1 and is immunologically distinct from the 56-kDa phorbol-diester hydrolase in mouse liver

Esterase 1, a well-characterized mouse plasma protein of unknown function, has activity against a wide range of ester substrates including beta-alanine nitrophenyl esters and 17 beta-esters of estradiol. In this article, we report that esterase 1 is also responsible for a majority of the phorbol-12-ester hydrolase activity in mouse plasma. Incubation of homogeneous esterase 1 with 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA) at either 4 or 37 degrees C for up to 18 h yielded phorbol 13 alpha-acetate as the only hydrolysis product. Specific polyclonal antibodies to esterase 1 inhibited 95% of PMA hydrolysis by a purified esterase 1 preparation and 65% of PMA hydrolysis by mouse plasma. Perfused mouse liver homogenates contain two distinct phorbol diester hydrolases with apparent molecular masses of 65 kDa and 56 kDa, respectively. The 65-kDa protein appears to be immunologically identical to the plasma enzyme, while the 56-kDa protein, found in liver but not in plasma, is immunologically distinct. Phorbol 12-myristate, phorbol 12,13-dibutyrate, and PMA were found to be competitive inhibitors of the beta-alanine-nitrophenyl esterase activity of esterase 1 with Ki values of approximately 7 microM. Phorbol 13-acetate and phorbol itself were less effective with Ki values of 37 and 140 microM, respectively. Sodium salts of valeric and myristic acids did not inhibit at 10 microM. The above results indicate that efficient substrate binding requires a phorbol 12-ester. Similar results were obtained with estradiol 17 beta-valerate which is a better substrate for esterase 1 than is PMA. Our results strongly suggest that esterase 1 and a recently described phorbol ester hydrolase isolated from mouse serum (Saito, M., and Egawa, K. (1984) J. Biol. Chem. 259, 5821-5826) are the same and are immunologically and kinetically distinct from the 56-kDa phorbol 12-ester hydrolase in mouse liver.     

Direct observation of cell wall glucans in whole cells of Saccharomyces cerevisiae by magic-angle spinning 13C-nmr

Intact cells of Saccharomyces cerevisiae were examined as an aqueous paste by ¹³C-nmr spectroscopy with direct polarization and magic-angle spinning. The spectra obtained were highly resolved, showing numerous resonances in the 60-105 ppm range that were assigned to carbons of a liquid-like domain of the cell wall glucan. Assignments were confirmed by running the spectrum of S. cerevisiae in which the cell wall glucans were labeled with [¹³C] by feeding the cell [¹³C ] galactose. The spectra indicate that the glucan in the cell wall of intact S. cerevisiae assumes a helical conformation and suggest that strain 17A fed with galactose preferentially incorporates the resulting glucose into β(1 → 3)-linkages. © 1994 John Wiley & Sons, Inc.     

Observation on the incorporation cone in the rat

At the time of in vivo sperm–egg fusion in the rat, a small region of the oolemma under the head of the fertilizing sperm is observed to be free of microvilli. The microvilli-free region increases in area, and by one hour after sperm–egg contact extends over an area 20–30 μ in circumference and bulges out to form an “incorporation cone” visible by light microscopy. The microvilli-free incorporation cone reaches its maximum size at about two hours after sperm–egg interaction. It soon becomes smaller and has disappeared three to four hours after sperm–oocyte fusion. The cone cytoplasm is characterized by a 0.1 μ zone of thin filaments below the plasma membrane. Cytochalasin-B, 2.5 μg/ml, prevents formation of the cone or destroys the intact cone. It is suggested that micro filaments may be involved in the formation of the incorporation cone.     

Dipole source localization by the mottled sculpin II. The role of lateral line excitation patterns

Extracellular, single unit recording techniques were used to measure the responses of posterior lateral line nerve fibers to a 50-Hz dipole source that slowly changed its location along the length of the fish. The flow-field equations for a dipole source were used to model the pressure gradient pattern and thus, the expected excitation pattern along a linear array of lateral line receptor organs for different source locations. Finally, excitation patterns were similarly modeled along the left and right side of the fish's head for actual steps taken by sculpin in approach pathways to the 50-Hz dipole source. Spatial histograms of posterior lateral line nerve fiber responses to different locations of the dipole source could be predicted from pressure gradient patterns modeled from the flow-field equations, confirming that the modeling approach applied to behavioral results was a good predictor of excitation patterns likely to be encoded by the lateral line periphery. An examination of how modeled excitation patterns changed from one position to the next in typical approach pathways and how patterns differed between positions from which successful and unsuccessful strikes were launched suggests that approach and strike strategies can indeed be explained by the information available in excitation patterns. In particular, changes in the spatial distribution of pressure gradient directions (polarities), available only when the source is lateral (as opposed to directly in front of the fish), appear to enhance the ability of sculpin to determine source distance. Without such information, misses are more likely to occur and successful strikes are more likely to be launched from short distances only. Accepted: 23 October 1996     

Perinatal brain damage: predictive value of metabolic acidosis and the Apgar score.

To assess the predictive value for perinatal brain damage of acidosis at birth, alone or in combination with the Apgar score at 5 minutes, a cohort of 982 liveborn infants delivered over two months was studied prospectively. The umbilical cord was double clamped, and arterial acid-base values were successfully determined in 964 infants and lactate concentration in 931. Reference values defining acidosis (mean +/- 2 SD) were obtained from a subset of 127 term infants who had no complications. The incidence of a low pH was 12% (111 out of 964), high base deficit 7% (70 out of 964), high lactate concentration 9% (83 out of 931), and low Apgar score at 5 minutes (less than or equal to 7) 3% (32 out of 982). Twelve of the 111 infants (11%) with acidosis had a low Apgar score, and 12 out of 29 infants (41%) with low Apgar scores had acidosis. At one year of age 35 infants were lost to follow up and 22 had an adverse outcome unrelated to asphyxia; 883 infants showed normal development but the possible sequelae of asphyxia were four deaths, slight abnormalities in 28 infants, and clear abnormalities in 10. The sensitivity and the positive predictive value of low pH for adverse outcome were, respectively, 21 and 8%, of high lactate concentration 12 and 5%, and of low 5 minute Apgar score 12 and 19%. Metabolic acidosis determined in blood from the umbilical artery at birth is a poor predictor of perinatal brain damage.     

Prostaglandin E1 binding and adenylate cyclase activation in normal and transformed fibroblasts

The binding of [³H]prostaglandin E₁ to membranes of clones of normal rat kidney fibroblasts (NRK cells) has been measured. Cell lines that responded to prostaglandin E₁, such as NRK and NRK transformed with Schmitt-Ruppin strain of Rous sarcoma virus (SR-NRK cells), have a high affinity prostaglandin E₁ binding site. Murine-sarcoma-virus-transformed lines of NRK cells are unresponsive to prostaglandin E₁ and have reduced prostaglandin E₁ binding. Exposure of cells to prostaglandin E₁ results both in decreases prostaglandin E₁ responsiveness and reduced prostaglandin E₁ binding.Activation of adenylate cyclase is correlated to binding of prostaglandin E₁ to receptors in both NRK and SR-NRK cell membranes. Mathematical models suggest that GTP decreases the affinity of hormone for its receptor while increasing the catalytic efficiency of adenylate cyclase, and that aggregates of occupied receptors may play an important role in the activation of adenylate cyclase.     

Effects of phytate reduction,fat extraction,and level of Ca on Ca and Zn bioavailability

The effect of phytate reduction, fat extraction, and addition of Ca in the form of skim or whole milk on Ca and Zn bioavailability from a breakfast containing bran muffins was studied in vitro and in vivo. Ca and Zn solubility were measured after in vitro simulated peptic and pancreatic digestion under pH conditions resembling those in the human GI tract. Absorption of Ca and Zn was measured in rats fed test meals tagged with 45Ca and 65Zn. Radioactivity in the femur and liver relative to levels found in rats injected with the isotopes served as criteria for 45Ca and 65Zn absorption, respectively. In vitro solubility was significantly depressed by the presence of phytate and inversely correlated with the phytate:Zn and the (phytate)(Ca):(Zn) ratios. Ca solubility was enhanced by extraction of fat and markedly increased by reduction in both fat and phytate. None of these effects was seen in vivo. However, 65Zn absorption was significantly decreased by fat extraction and phytate reduction although this treatment increased in vitro Zn solubility. Possible reasons for these discrepancies are discussed.