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Biomedical subjects

K Bergman

Publications and source records attributed to K Bergman.

At least 37 records · Page 2Linked to original sources
PubMed1990

Accumulation and turnover of metabolites of toluene and xylene in nasal mucosa and olfactory bulb in the mouse.

Autoradiography of male mice following inhalation of the radioactively labelled solvents, toluene, xylene, and styrene, revealed an accumulation of non-volatile metabolites in the nasal mucosa and olfactory bulb of the brain. Since no accumulation occurred after benzene inhalation, it was assumed that the activity represented aromatic acids, which are known metabolites of these solvents. This was supported by the finding that also radioactive benzoic acid (main metabolite of toluene) and salicylic acid accumulated in the olfactory bulb. High-performance liquid chromatography revealed that after toluene inhalation (for 1 hr), nasal mucosa and olfactory bulb contained mainly benzoic acid, with a strong accumulation in relation to blood plasma, and considerably less of its glycine conjugate, hippuric acid. After xylene inhalation, on the other hand, methyl hippuric acid dominated over the non-conjugated metabolite, toluic acid. The results indicate a specific, possibly axonal flow-mediated transport of aromatic acids from the nasal mucosa to the olfactory lobe of the brain. The toxicological significance of these results remains to be studied.

Animals↗
PubMed1990

PET imaging in obsessive compulsive disorder with and without depression.

Obsessive compulsive disorder (OCD) is a classic psychoneurosis which is frequently complicated by major depression. Recent positron emission tomography neuroimaging studies, when taken in the context of a variety of other data, implicate a brain dysfunction involving the orbital prefrontal cortex and the striatum in the mediation of OCD behaviors and those of the related Gilles de la Tourette's syndrome. The anterolateral prefrontal cortex is implicated in the secondary major depressions often complicating OCD.

Brain↗
PubMed1990

Thoracic vascular injuries: a post mortem study.

We reviewed the coroner's records for all pediatric (less than 16 years of age) trauma fatalities in Ontario (population, 9.5 million) for the period January 1, 1985, through December 31, 1987. Twenty-six (8%) of the 322 cases for which complete autopsy data were available had major thoracic vascular injuries. Twenty-five deaths occurred within 6 hours of injury. The majority of patients had at least one AIS 6 injury. The aorta was the most frequently injured vessel. Major thoracic vascular injuries are more common among children than previous reports suggest, probably because they are rapidly fatal. Many deaths occur in the field, at local hospitals, or in transit before the patient can reach a trauma center. Efforts to reduce the number of total thoracic vascular injuries should focus on primary and secondary prevention.

Adolescent↗
PubMed1988

Physiology of behavioral mutants of Rhizobium meliloti: evidence for a dual chemotaxis pathway.

Wild-type and nonchemotactic mutant strains of Rhizobium meliloti were tested for attraction to localized sites on alfalfa roots and for attraction to numerous small molecules, including sugars, amino acids, and two fractions derived from alfalfa root extracts. Four strains (carrying mutations che-6, che-11, che-12, and che-26) lost all responses and were classified as generally nonchemotactic mutants. One strain (carrying mutation che-7) lost responses to a group of structurally unrelated amino acids but retained all other responses and was classified as a putative sensory transducer mutant. Two strains (carrying mutations che-1 and che-3) lost responses to all the amino acids and sugars tested but retained normal responses to localized sites on roots and to the root fractions. These two mutant strains could not be classified according to the generally accepted model for a sensory pathway, derived from studies of enteric bacteria, and provided evidence for a dual chemotaxis pathway in R. meliloti.

Amino Acids↗
PubMed1988

Collective dose to the Swedish population from intraoral radiography.

In 1984 the Swedish National Institute of Radiation Protection (SSI) undertook an investigation (KAST) of 400 randomly selected dental offices to check the extent to which the new rules and recommendations concerning radiation protection (SSI 1978, 1980) were applied. Data for calculation of the energy imparted per bitewing examination of an adult were available. The information obtained was utilized for estimating the collective dose in Sweden from intraoral radiography. The mean value of the energy imparted from an ordinary bitewing examination was 0.48 mJ. The quotient between the sum of all imparted energy during 1984, 5,519 J, and the number of inhabitants in that year was 0.66 mJ. This corresponds to 1.5 ordinary bitewing examinations per individual in Sweden. The collective effective dose equivalent is 79 manSv after transformation from the total energy imparted. The average energy imparted from the annual natural irradiation in Sweden is 100 mJ, with variations between 35 and 350 mJ, giving totally to the population 830,000 J. The dose contribution from intraoral radiography is thus considered of minor importance when taking into account the variations of the natural irradiation as well as the benefit of the diagnostic gain in dentistry and the enhancement of public dental health.

Adult↗
PubMed1987

Di-(2-ethylhexyl)adipate: absorption, autoradiographic distribution and elimination in mice and rats.

Whole-body autoradiography was used to study the tissue distribution of the plasticizer di-(2-ethylhexyl) adipate (DEHA), labelled in the acid [carbonyl-14C] or alcohol [2-ethylhexyl-1-14C]moiety, after iv or ig administration to male mice and rats and pregnant mice. With both DEHA preparations, during the first 24 hr after administration high levels of radioactivity were observed particularly in the body fat, liver and kidneys (after iv and ig administration) and in the intestinal contents (after ig administration) of both species. After administration of [carbonyl-14C]DEHA, radioactivity was also registered in the adrenal cortex, corpora lutea of the ovary, bone marrow, forestomach mucosa, salivary glands and Harder's gland in both species. [2-ethylhexyl-1-14C]DEHA derived radioactivity was found in the bronchi in male mice. Radioactivity was observed in the foetal liver, intestine and bone marrow during the first 24 hr after iv or ig administration of [carbonyl-14C]DEHA to pregnant mice. There was very little accumulation of [2-ethylhexyl-1-14C]DEHA in the mouse foetus but some was found in the urinary bladder, liver and intestinal contents as well as in the amniotic fluid. In an absorption/elimination study in rats of doses of 25 microCi/kg body weight of [14C]DEHA administered ig, dissolved in corn oil or dimethylsulphoxide, blood levels of radioactivity increased somewhat faster and were two or three times higher when DMSO was the vehicle indicating poor absorption of DEHA from the corn oil solution which more accurately reflects human contact with DEHA. Little radioactivity from [carbonyl-14C]DEHA was recovered in the bile, whereas [2-ethylhexyl-1-14C]DEHA was excreted in the bile in significant amounts particularly when DMSO was the vehicle. There was evidence of enterohepatic circulation of DEHA. Radioactivity was also excreted in the urine. As shown by autoradiograms obtained 4 days after the administration of [14C]DEHA there was no retention of DEHA and/or its metabolites in the tissues of mice.

Adipates↗
PubMed1986

Mapping and cloning of a fla-che region of the Rhizobium meliloti chromosome.

We constructed a genetic map of the fla-che region of the Rhizobium meliloti chromosome using cotransduction with bacteriophage phi M12. Several other chromosomal markers located in the general area are included in the map. We isolated plasmids carrying wild-type DNA inserts that complement the mapped mutations from a genomic library carried in the broad-host-range vector pLAFR1. The complementation data obtained from the clones confirmed the contransduction map and clarified the exact order of several of the behavioral genes. A restriction map of this area was developed by using the cloned DNA. One of the five individual EcoRI fragments subcloned from the original clones complemented two of the behavioral mutations.

Cell Movement↗