The November 15, 1991, workshop on record linkage methodology.
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Biomedical subjects
Publications and source records attributed to M Carpenter.
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It has recently been shown that caldesmon from non-muscle (Yamashiro, S., Yamakita, Y., Hosoya, H., and Matsumura, F. (1991) Nature 349, 169-172) and smooth muscle cells (Mak, A. S., Watson, M. H., Litwin, C. M. E., and Wang, J. H. (1991) J. Biol. Chem. 266, 6678-6681) can be phosphorylated in vitro by p34cdc2 kinase resulting in the inhibition of caldesmon binding to F-actin and Ca(2+)-calmodulin. In this study, we have identified five phosphorylation sites in smooth muscle caldesmon at Ser582, Ser667, Thr673, Thr696, and Ser702. All the sites bear some resemblance to the S(T)-P-X-X motif recognized by p34cdc2. The preferred site of phosphorylation at Thr673 accounts for about 40% of the total phosphorylation. Four of the sites occur in two pairs of closely spaced sites, Ser667/Thr673 and Thr696/Ser702; phosphorylation of one site in each pair inhibits strongly the phosphorylation of the second site in the same pair, presumably due to the close proximity of the two sites. Similar negative cooperativity in phosphorylation of Ser667 and Thr673 was observed using a 22-residue synthetic peptide containing the two sites. Phosphorylation of Ser667/Thr673 and Thr696/Ser702 account for about 90% of the total level of phosphorylation and these sites are located within the 10-kDa CNBr fragment at the COOH-terminal end of caldesmon known to bind actin and Ca(2+)-calmodulin.
A standard method of collecting identifying data for medical follow-up studies has been developed by Statistics Canada. By helping improve health record-keeping, this method has the potential to make it easier to track populations exposed to potentially hazardous agents through lifestyle, work, environmental factors, ecological disasters, or medical treatments. The data collection package, which has been reviewed by expert groups and pilot tested, can reduce costs, save time and result in more comparable data. The package guides the user in developing an easily maintained and accessed database using either the Data Collection Package handbook or the personal computer package option. Part I of this article gives an overview of the new data collection package and how it can be used. Part II gives the background and methodological notes on its development.
In the course of characterizing polyclonal antibodies to beta nerve growth factor (NGF) on immunoblot replicas of sodium dodecyl sulfate gels, we observed a protein (designated C protein) migrating as two bands (14.0 and 13.5 kDa) that copurifies with NGF and reacts strongly with its antibodies. The molecule is detectable in the 7 S, beta, and 2.5 S forms of NGF, accounting in the latter two for approximately 2% of total protein. The C protein can be separated from the A and B chains of beta-NGF on acetic acid-urea gels and on two-dimensional gels but not by isoelectric focusing alone. The molecule has been isolated to near purity on reversed-phase high performance liquid chromatography. Amino acid analyses and sequencing through 49 Edman cycles revealed that the protein preparation is composed of the intact and desoctapeptide (des-(1-8] polypeptide chains and suggested a glycosylation site at Asn-45. Following digestion with N-glycanase, the chains migrated on sodium dodecyl sulfate gels identically with the A and B chains of beta-NGF. Although this was accompanied by some degree of proteolytic degradation, the presence of glucosamine (approximately 4 mol/mol of single chain) was confirmed in acid hydrolysates on the amino acid analyzer. No amino sugars were detected in hydrolysates of the A chain nor was galactosamine recovered in either preparation. Glycosylated NGF promotes neuronal growth and survival in a manner indistinguishable from native 2.5 S NGF when tested in the chick sensory ganglion assay and with rat postnatal sympathetic neurons in a dissociated culture cell survival assay or in a compartmentalized culture growth assay. These studies reveal that NGF can be modified by glycosylation in a manner that does not reduce its biological activity.
The behavioral response to amphetamine was monitored in rats that received simultaneous intraventricular infusions of saline or ascorbate. Both groups of animals displayed comparable responses, although ascorbate significantly delayed the onset of amphetamine-induced locomotion and rearing. In rats pretreated with a threshold dose of haloperidol (0.025 mg/kg), virtually all aspects of the amphetamine response were attenuated, and this effect was enhanced by ascorbate. In haloperidol-pretreated rats, ascorbate significantly lowered sniffing and forepaw shuffling throughout the amphetamine response. These results suggest that ascorbate antagonizes dopaminergic transmission by a central mechanism.
This population-based study analyzes maternal serum alpha-fetoprotein (MSAFP) distributions for 20 cases of gastroschisis and 13 cases of omphalocele occurring in singleton pregnancies from among 72,782 second-trimester pregnancies in Maine and Rhode Island screened consecutively between January 1, 1979 and February 28, 1987. Median values (and ranges) for the two lesions were 4.1 multiples of the median (0.5-29.8) for omphalocele and 7.0 multiples of the median (3.6-13.5) for gastroschisis. The MSAFP distributions for the two conditions were both log-Gaussian, and the log standard deviation was smaller for gastroschisis than for omphalocele. The MSAFP screening sensitivity was greater for gastroschisis than for omphalocele at any given cutoff, and the overall sensitivity of this screening process for detecting open ventral wall defects will differ, therefore, depending upon the relative proportion of gastroschisis and omphalocele cases that occur in the screened population.
Various agents were tested for their ability to antagonize the acute excitotoxic action of N-methyl-DL-aspartate (NMA) and kainic acid (KA) on neurons in the in vitro chick embryo retina. The following compounds (in order of descending potencies) were effective in completely blocking the neurotoxic activity of NMA: phencyclidine, ketamine, (+/-)-SKF 10,047, pentazocine, D-aminophosphonovalerate, D-amino-phosphonoheptanoate, D-alpha-aminoadipate, OH-quinoxaline carboxylate, kynurenate, (+/-)-cis-2,3-piperidine dicarboxylate, secobarbital, amobarbital and pentobarbital. The latter 6 agents also protected against KA toxicity but complete protection was observed only from relatively high concentrations. At 20 mM, Mg2+ blocked NMA toxicity but at concentrations up to 30 mM did not block KA toxicity. Compounds that failed to block either NMA or KA toxicity include D- and L-aminophosphonobutyrate, L-glutamic acid diethyl ester, xanthurenate, GABA and taurine. The chick embryo retina is a useful preparation for identifying agents that have either excitotoxic or anti-excitotoxic activity.
Pseudomonas aeruginosa strains PAO and PAK bear polar pili which are flexible filaments having a diameter of 6 nm and an average length of 2500 nm. Both types of pili are retractile and promote infection by a number of bacteriophages. The present communication describes the partial biochemical characterization of PAO pili isolated from a multipiliated nonretractile mutant of PAO. The observed properties are compared to those of PAK pili which were characterized previously. PAO pili were found to contain a single polypeptide subunit of 18 700 daltons. This is similar to PAK pili which contain a single polypeptide of 18 100 daltons. The amino acid composition of PAO pilin was also similar to that of PAK pilin. Neither protein contained phosphate or carbohydrate residues and both were found to contain N-methylphenylalanine at the amino terminus. Sequencing of 20 amino acid residues at the amino terminal end of PAO pilin revealed the sequence to be identical with that of PAK pilin, while tryptic peptide analyses of PAO and PAK pilin indicated that the two proteins probably contain a number of homologous regions within the polypeptide. It was concluded that PAO and PAK pili were closely related structures.
The effect of 3 wk heat exposure (Ta 34 degrees C) on intestinal weight and intestinal absorption of D-glucose and D-galactose in vitro was examined in the rat. Intestinal dry weight was reduced with heat exposure compared to both ad libitum and pair-fed animals at Ta 22 degrees C. Intestinal tissue water was elevated after pair feeding but not heat exposure; extracellular (inulin) space was similar in the three groups. Mucosal uptake of glucose per gram wet weight in an everted sac preparation was unchanged compared to pair-fed animals, but serosal transfer was increased. Intestinal metabolism of glucose was decreased with heat exposure. Galactose accumulation with 30 min incubation was increased in intestinal rings from both heat-exposed and pair-fed animals. This increase is likely to be related to the reduction in ring size present in the groups with reduced food intake. Vmax and apparent Km for galactose transport were unchanged. Our results indicate that despite a reduction in intestinal weight following heat exposure, the ability of the intestine to transport hexoses per gram remains relatively stable. Alterations of hexose transport appear to be related to altered glucose metabolism and not altered transport capacity. Differences in intestinal weight and glucose utilization between pair-fed and heat-exposed animals suggest that the intestinal response to chronic heat exposure is not solely a function at the amount of food consumed. However, the alteration of more than one variable in pair feeding makes interpretation complex.
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The amino-terminal amino acid sequence of the pili protein from Pseudomonas aeruginosa K pili is presented. The sequence is compared with those reported by others for pilin obtained from Neisseria gonorrhoeae and Moraxella nonlique-faciens. All three sequences are highly homologous, contain only two hydrophilic residues in the first 22 positions, and contain an unusual amino acid, N-monomethylphenylalanine, at the amino terminus.