Search PubMed⌕ Search

Biomedical subjects

C R Harris

Publications and source records attributed to C R Harris.

At least 37 records · Page 2Linked to original sources
PubMed1993

Accidental administration of activated charcoal into the lung: aspiration by proxy.

We report a case of accidental activated charcoal instillation into the lung of a 30-year-old man being managed for a cyclic antidepressant overdose. The patient was treated with multidose activated charcoal, and between his first and second doses, he pulled his nasogastric tube out of position. The tube was reinserted past the endotracheal tube into the right mainstem bronchus, and a dose of activated charcoal with sorbitol was administered into the lung. He subsequently developed an adult respiratory distress syndrome but gradually improved after bronchoscopic removal of charcoal and supportive care. He was discharged 14 days later.

Adult↗
PubMed1992

Gastrointestinal decontamination. Which method is best?

Why has ipecac syrup become less popular in emergency management of poisoning and overdose? When should gastric lavage, activated charcoal, cathartics, or a combination of methods be used? Which patients are candidates for whole-bowel irrigation with polyethylene glycol-electrolyte solution? Drs Harris and Kingston answer these questions and present their recommendations for each of the available management options.

Cathartics↗
PubMed1989

A conservative amino acid substitution, arginine for lysine, abolishes export of a hybrid protein in Escherichia coli. Implications for the mechanism of protein secretion.

A hybrid protein that comprises the beta-lactamase signal peptide fused precisely to chicken muscle triosephosphate isomerase is not secreted into the periplasm of Escherichia coli. The protein can be secreted, however, if an arginine residue at position 3 of the isomerase is replaced by either a serine or a proline residue. In contrast, replacement of a neighboring lysine residue has no effect on secretion of the protein. Furthermore, if the arginine is removed from position 3 to generate a secreted protein, but is then reintroduced in place of the neighboring lysine, the blockade to secretion is re-established. The singular effect of the arginine residue on secretion does not result from the role this residue plays in the formation or stabilization of the native isomerase structure: mutational alterations remote from the N terminus of the isomerase that prevent the proper folding of the protein do not relieve the block to secretion. The finding that an arginine residue prevents secretion while a lysine residue does not, suggests that basic residues near the mature N terminus of a secreted protein must be deprotonated if orderly export is to occur. This implies that the signal peptide along with the N-terminal portion of the mature protein partitions directly into the lipid bilayer in the course of the secretory process.

Amino Acid Sequence↗
PubMed1989

Appendiceal stump abscess ten years after appendectomy.

A case of an appendiceal stump abscess occurring 10 years after appendectomy is presented. Although appendiceal stump abscess rarely appears years after an appendectomy, the possibility still exists and should be considered in the differential diagnosis of right lower quadrant abdominal pain.

Abdomen, Acute↗
PubMed1989

Population genetics of the highly polymorphic locus D16S7 and its use in paternity evaluation.

We have developed a DNA RFLP test to resolve paternity cases in which the accused man is included at a low probability of paternity by conventional testing. The DNA probe p79-2-23 was used to determine the allele frequency distribution for the locus D16S7 in the North American black, Caucasian, and Hispanic racial groups. Approximately 3,500 TaqI-digested DNAs were analyzed from the three populations studied. An apparent continuum of alleles was detected varying in size from 2.9 kb to 8.3 kb. Estimates of the average probability of exclusion were found to be .90 and .79 for the North American black and Caucasian populations, respectively. Gene frequency data for common and rare alleles indicated a potential paternity index ranging from 2 to 450.

Alleles↗
PubMed1988

A comparison of the persistence in a clay loam of single and repeated annual applications of seven granular insecticides used for corn rootworm control.

In May 1983, granular formulations of carbofuran, chlorpyrifos, disulfoton, fonofos, isofenphos, phorate, and terbufos were applied in incorporated bands to duplicate 2 m2 field plots of clay loam. Insecticide concentrations were determined in the bands at 0,1,2,3,4,6,8,10,12,16, and 20 wk. Following spring cultivation, the insecticides were applied to the same plots in 1984 and 1985. In addition, carbofuran was applied to previously untreated plots in 1984 and all 7 materials were applied to previously untreated plots in 1985. Sampling and analysis were carried out as in 1983. Persistence was assessed on the basis of the disappearance rates measured for the 1st 8 wk and of a calculated Effectiveness Potential (the ratio of the average residue in the upper 5 cm of the band at 8, 10 and 12 wk and the published LC95 for western corn rootworm in clay loam soil). Soils treated with carbofuran and isofenphos in 1984 and all soils treated in 1985 were tested for anti-insecticide activity. Soil cores from some carbofuran, chlorpyrifos and terbufos treated plots were sectioned vertically to establish the distribution of the insecticides during 1985. In addition, granular and pure chemical forms of isofenphos and carbofuran were applied at 10 ppm to anti-isofenphos and anti-carbofuran active and control soils (from field plots) maintained at 10 and 20% moisture in the laboratory to assess the effect of formulation and moisture on persistence in active soils. Insecticide concentrations were determined at 0,1,3,7, 10,14,21,28, and 35 days. The persistence of chlorpyrifos, terbufos and phorate was relatively constant over the 3 years and between plots receiving single and multiple treatments. Disulfoton and fonofos behavior was more variable and that of carbofuran and isofenphos was extremely variable. Anti-insecticide activity against carbofuran and isofenphos was detectable 2 wk after an initial application and was still present the following spring. Anti-insecticide activity against fonofos, terbufos sulfoxide, phorate sulfone and disulfoton sulfone was also generated in this soil. Anti-insecticide activity against chlorpyrifos, disulfoton, terbufos and phorate was not present. Carbofuran, chlorpyrifos and terbufos (+ metabolites) present in the upper 5 cm of soil averaged 93, 94 and 94%, respectively, of the total core contents over 12 wk. Significant moisture dependent differences were observed between the behavior of granular carbofuran and granular isofenphos in anti-insecticide active soils.(ABSTRACT TRUNCATED AT 400 WORDS)

Chromatography, Gas↗
PubMed1988

Dosimetry considerations in far field microwave exposure of mammalian cells.

A circulating water bath exposure system has been designed for in vitro radiofrequency radiation (RFR) exposure studies in the 915 to 2450 MHz range. A Styrofoam float, in which 10 T-25 plastic tissue culture flasks are embedded, is rotated at approximately 20 rpm in a Plexiglas water bath at a distance beneath a rectangular horn. The continuous circular rotation of the flasks is designed to "average out" the heterogeneity present in stationary flask exposures. The rotation also serves to prevent the establishment of chemical gradients in the medium within the flasks. Several factors have been demonstrated to affect the specific absorption rate (SAR) measured in the medium in the exposed flasks. These factors include: 1) the position of the exposure flasks relative to the long axis of the antenna horn; 2) whether the flasks are exposed while stationary or in rotation; 3) the volume of the medium contained in the flask; and 4) the depth in the medium in the flask at which temperatures for SAR calculation are measured. The presence of cells in the exposure flask (as attached monolayer or cell suspension) did not result in an SAR different from that measured in the same volume of medium without cells present.

Cells↗
PubMed1986

The in vitro radiobiology of astatine-211 decay.

Chinese hamster V79 cells in culture were exposed to astatine-211, an alpha-particle-emitting radiohalogen. The dose-log survival response was linear with no detectable shoulder. Cells in monolayers had a D0 of 1.0 microCi/ml. Suspended cells had a D0 of 0.60 microCi/ml with a cellular uptake of 2.5 fCi/cell; this is equal to approximately 1.5 alpha-particle traversals per cell nucleus. The frequencies of chromosome and chromatid breaks were linear with dose, but the number declined rapidly with time. These data are discussed in relation to published alpha-particle beam studies and the potential use of 211At in radionuclide therapy.

Alpha Particles↗
PubMed1985

Blunt abdominal trauma causing jejunal rupture.

Two cases of jejunal rupture from blunt abdominal trauma are described. One followed a motorcycle accident, and the other followed a punch to the abdomen. Both patients initially had unremarkable abdominal examinations. After surgical repair of the ruptures, the patients recovered uneventfully. Jejunal rupture secondary to blunt abdominal trauma is not common, but its subdued clinical presentation and the nonspecific laboratory findings make diagnosis difficult. High morbidity and mortality are associated with this type of injury when diagnosis and treatment are delayed. Small bowel rupture should be considered in any patient with a history of significant blunt abdominal trauma and persistent abdominal pain.

Accidents, Traffic↗
PubMed1985

Measurement of absorbed dose from radionuclide solutions mixed intimately with the FBX dosimeter.

Chemical dosimeters are used widely for accurate measurement of large radiation doses due to external beam irradiation from radionuclide sources and from particle accelerators. Their use for measurement of absorbed doses from radioactive solutions mixed in the dosimeter solution was reported as early as 1952, but the large activities needed to produce suitable absorbance values in the relatively insensitive dosimeters of that time discouraged further work. This manuscript reports the results of an investigation into the suitability of the ferrous sulfate-benzoic acid-xylenol orange (FBX) dosimeter for measurement of small absorbed doses caused by radionuclide solutions mixed with the dosimeter solution. The FBX dosimeter exhibited a linear dose response as a function of activity for two common radiopharmaceuticals, 99mTc sodium pertechnetate and 131I sodium iodide. Conditions under which the FBX dosimeter may be used with radionuclide solutions were studied and were found to be amenable to routine use by laboratories possessing relatively unsophisticated instrumentation. That any radionuclide could be studied using this dosimeter appears likely.

Benzoates↗
PubMed1983

Assessment of hazards associated with pesticide container disposal and of rinsing procedures as a means of enabling disposal of pesticide containers in sanitary landfills.

To study problems associated with pesticide container disposal, a small vegetable production area in southwestern Ontario, the Thedford Marsh, was selected as the site for a model study. A container collection system was organized during the 1981 growing season, with collections being made from the ca. 50 growers on the marsh twice each month. In addition to the regular collection program a cleanup service for empty pesticide containers stored on farms or discarded on public lands also was initiated. More than 3600 containers were collected and disposed of at an authorized landfill site. Ca. 2/3 were herbicide containers, ca. 1/4 were insecticide containers, and 3% were fungicide containers. Unrinsed containers contained as much as 5 1/2% of the original contents with an average of 1%. Containers rinsed by the triple rinse method or using rinsing devices (E-Z Rinse, JET Rinse) generally contained less than 0.1% of the original content. Some formulations presented rinsing problems due to settling and caking. The results indicated that, while unacceptable quantities of pesticide residues remain in unrinsed containers, most rinsed pesticide containers will be acceptable for disposal at municipal sanitary landfill sites.

Accident Prevention↗