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C Schultz

Publications and source records attributed to C Schultz.

At least 55 records · Page 3Linked to original sources
PubMed1989

Isoenzyme analysis of typhoid-Shigella and Escherichia-Shigella hybrid vaccines and their parental strains.

Isoenzyme analysis can be used to measure phenotypic changes and to characterize bacterial strains. The use of isoenzyme analysis to characterize bacterial hybrid vaccine strains that were prepared for human vaccination is described in this report. The hybrid vaccine strains were two lots of Salmonella typhi-Shigella sonnei vaccine, two lots of Escherichia coli-Shigella flexneri vaccine, and their parental strains. The two lots of S. typhi-S. sonnei hybrid vaccine had only 5 of 11 reactive isoenzymes in common. The lot of S. typhi-S. sonnei hybrid vaccine that protected human volunteers in a clinical trial also had a greater degree of relatedness to the parental strain, S. typhi Ty21a, than the nonprotective lot. The two lots of E. coli-S. flexneri vaccine were more similar in terms of their isoenzyme profiles. There were colonial isolates from both lots that had identical isoenzyme profiles. The results also indicate a greater degree of homogenicity between Shigella spp. and E. coli than between either of these species and Salmonella spp. The data also show more isoenzyme activity associated with the nonpathogenic bacteria than with pathogenic isolates. Isoenzyme analysis is a rapid and specific assay that can be used to evaluate bacterial vaccine organisms and to establish isoenzyme profiles associated with vaccine immunogenicity and efficacy.

Bacterial Vaccines↗
PubMed1987

Investigations into the polymorphism of lipid A from lipopolysaccharides of Escherichia coli and Salmonella minnesota by Fourier-transform infrared spectroscopy.

The polymorphism of lipid A, the endotoxic principle of the lipopolysaccharides of gram-negative bacteria, has been investigated in the fully hydrated state at temperatures between 5 degrees and 58 degrees C via Fourier-transform infrared spectroscopy. These measurements were supplemented by X-ray diffraction, fluorescence intensity techniques and differential thermal analysis. Up to three distinct phase transitions could be detected, with the main transition temperatures lying at approximately 41 degrees, 46 degrees, 44 degrees and 47 degrees C for Escherichia coli lipid A, Salmonella minnesota lipid A, and the synthetic lipid A compounds 506 and 516, respectively. 4'-Monophosphoryl-lipid A samples exhibited their main transition temperatures at considerably higher temperatures (about 52 degrees C for E. coli lipid A). The analysis of greater than CH2 stretching absorption bands as well as the wide-angle scattering behaviour of the lipid A samples showed that the main transition apparently involved the completion of hydrocarbon chain melting of lipid A, as typically observed for phospholipids. However, the phase transition behaviour was found to be much more complex than that usually observed for model phospholipid systems. Even below the main transition temperature, considerable amounts of the methylene segments of the acyl chains of lipid A were found to assume gauche conformations. These conformational changes might be related to the occurrence of up to two further transitions located at about 22 degrees, 30 degrees, 27 degrees and 25.5 degrees C (first transition) and at about 34 degrees, 42 degrees, 38.5 degrees and 40.5 degrees C (second transition) for E. coli lipid A, S. minnesota lipid A and the synthetic lipid A compounds 506 and 516, respectively. Furthermore, by the analysis of some characteristic infrared absorption bands related to the hydrophilic backbone, it could be demonstrated that the temperature-induced conformational changes occurring within the hydrocarbon chains were constantly and simultaneously accompanied by detectable rearrangements within the interfacial region and the polar head group of lipid A. The following conclusions were drawn: Up to about 30 degrees C the lipid A assemblies were supposed to adopt virtually bilayered, true lamellar arrangements, as revealed by the analysis of greater than CH2 scissoring vibrations and X-ray diffraction pattern. However, as indicated by fluorometric techniques, no stable closed vesicles seemed to be formed even under these conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Calorimetry↗
PubMed1986

Protective effects of the synthetic prostaglandin enprostil on the gastric microvasculature after ethanol injury in the rat.

The effect of pretreatment with the synthetic prostaglandin E2 analogue enprostil on ethanol damage to the rat gastric mucosa was studied. Microvascular casts were prepared and studied by scanning electron microscopy. The permeability of mucosal capillaries to fluorescein isothiocyanate-labeled albumin (FITC-albumin) given intravenously was examined by fluorescence microscopy. After administration of ethanol (1 ml absolute ethanol intragastrically) alone, casts showed gross disruption of the normal structure, with large foci of loss of the patency of the capillary network, frequently extending to the level of the submucosal vessels. There was exudation of casting material into the mucosal interstitium and onto the surface of the cast. After administration of FITC-albumin, there was a marked increase in interstitial fluorescence throughout the full thickness of the mucosa. Pretreatment with enprostil (1 microgram/kg intragastrically) prevented most of the damaging effects of ethanol. Increased microvascular permeability to FITC-albumin was noted only in the most superficial layers of the mucosa. These studies characterize the effect of ethanol on the gastric microvasculature and indicate that pretreatment with enprostil restricts this damaging effect to the superficial mucosal microvessels. These studies further suggest that microvascular damage is an early event in ethanol injury, apparently preceding epithelial erosion.

Animals↗
PubMed1985

Methylation of plasmacytoma c-myc genes.

The chromosomal translocation associated with many tumors of immunoglobulin-producing cells frequently results in the joining of the immunoglobulin heavy-chain locus and the c-myc oncogene. This translocation of c-myc has profound structural and functional consequences for the oncogene, including loss of the 5' end of the gene and transcriptional deregulation. We report in this communication that translocation results in a new methylation pattern of c-myc. In normal kidney and liver tissue, the c-myc gene is methylated at its 3' end. The translocated gene in plasmacytoma DNA is extensively demethylated. On the other hand, the nonrearranged c-myc gene in plasmacytoma DNA (which is transcriptionally silent) is extensively methylated. In addition, we confirm the nucleotide sequence (with 19 discrepancies out of 1400 bp) 5' to the murine c-myc gene, as reported by Corcoran et al. [Cell 40 (1985) 71-79].

Animals↗
PubMed1984

The role of annotated bibliographies in information dissemination.

In July 1982, a comprehensive questionnaire was sent to a random sample of names on the National Diabetes Information Clearinghouse (NDIC) mailing list to measure user satisfaction with and use of annotated bibliographies about diabetes topics. The bibliographies are used to learn more about a topic and to locate cited materials. The total number of publications ordered by this sample is 8,857; therefore, an extrapolation from these data suggests that more than 45,000 publications were ordered as a direct result of the citations as the source of information.

Bibliography of Medicine↗
PubMed1983

Body size estimation and locus of control in obese adolescent boys undergoing weight reduction.

Body size estimation (BSE) and locus of control (LOC) were studied in 18 obese adolescent boys undergoing weight reduction. The subjects attended a seven-week summer camp which offered both increased activity and a 1200 kcal (5023 kJ)/d diet, resulting in an average weight loss of 29.2 +/- 6.3 lb (13.3 +/- 2.9 kg) and a decrease in body fat from 39.0 percent +/- 0.6 percent to 27.5 percent +/- 4.3 percent. Fatness was correlated with poor physical performance [1.5 mile (2.4 km) runs]. Weight reduction and decreased body fat resulted in an improved running time. BSE was assessed using self photographs distorted by an anamorphic lens. While subjects could correctly estimate their body size prior to weight reduction, after weight reduction they significantly underestimated body size. This finding contrasts with adults with juvenile-onset obesity who overestimate body size after weight reduction. LOC (measured by Nowicki-Strickland LOC Inventory) changed in the direction of internality after weight reduction. The use of exercise with the weight loss program may thus improve feelings of control and prevent overestimation of body size.

Adolescent↗
PubMed1975

The inhibition of bacterial growth by ochratoxin A.

A series of bacterial species was examined for their sensitivity to ochratoxin A. Only grampositive bacteria could be inhibited, generally at a pH lower than 7.0. Bacillus subtilis did not show any reduction of growth rates in presence of ochratoxin A, but had a prolonged lag phase. With Staphylococcus pyogenes var. aureus and Streptococcus faecalis, a prolonged lag phase and a reduction of the growth rate was observed. Most sensitive was Streptococcus faecalis in the exponential-growth phase. The inhibition could be diminished by changing the pH to neutral, or by addition of yeast extract, tetrahydrofolate, or MgSO4. With MgSO4 a complete abolition of the inhibitory effect was achieved, but not with CaCl2. During growth inhibition, protein and RNA synthesis were reduced simultaneously, but not DNA synthesis. Even with the very high concentration of 1 mg/ml, no lethal effect was observed.

Aspergillus↗