Properties of a rat liver smooth microsomal subfraction not aggregated by Mg2+.
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Animals↗
Biomedical subjects
A Bergman
Publications and source records attributed to A Bergman.
Distribution of polychlorinated biphenyls: structural requirements for accumulation in the mouse bronchial mucosa.
Autoradiography showed that labelled polychlorinated biphenyls with chlorine in positions 2, 41, 5 and hydrogen in positions 3, 31, 6, 61 in the molecule are accumulated in the mouse bronchial mucosa. Further testing of this observation showed that 2, 21, 4, 51-tetrachlorbiphenyl-14C, but not biphenyl-14C, was taken up in the bronchi of mice.
Animals↗
A shared experience.
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Attitude of Health Personnel↗
[Not Available].
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History, Modern 1601-↗
Toxicity of 2,2',4,4',5,5'-hexachlorobiphenyl in rats: effects following 90-day oral exposure.
The subchronic toxicity of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) was investigated in rats after 13 weeks of dietary exposure. Groups of 10 male and 10 female rats were administered PCB 153 in their diet at levels of 0.05, 0.50, 5.0 or 50 ppm for 13 weeks. The control groups received the diet containing 4% corn oil. Growth rate and dietary consumption were not affected by treatment. Clinical signs of toxicity were not observed. Enlarged, fatty liver was observed in treated animals at necropsy, but most were confined to the two highest dose groups. Increased hepatic microsomal ethoxyresorufin-O-deethylase, aminopyrine-N-demethylase and aniline hydroxylase activities occurred in high-dose groups of both sexes, with increased ethoxyresorufin-O-deethylase activity being observed starting at 0.05 ppm in females and at 0.5 ppm in males. Treatment-related reduction in hepatic and pulmonary vitamin A was seen in the highest dose group of both sexes. Changes in brain biogenic amines and intermediate products were observed mainly in females; these included decreased dopamine and 5-hydroxytryptamine concentrations in the frontal cortex region, and dihydroxyphenylacetic acid in the caudate nucleus region at 5.0 and 50 ppm. Female rats appeared to be more sensitive to the neurotoxic effects of PCB 153 than males. Dose-dependent histological changes were observed in the thyroid and liver of rats of both sexes and significant changes occurred at 5.0 and 50 ppm. Based on these data, the no-observable-adverse-effect level (NOAEL) of PCB 153 was judged to be 0.5 ppm in the diet or 34 micrograms kg-1 body wt. day-1.
Animals↗
Subchronic toxicity of PCB 105 (2,3,3',4,4'-pentachlorobiphenyl) in rats.
The toxicity of 2,3,3',4,4'-pentachlorobiphenyl (PCB 105) was investigated in Sprague-Dawley rats following dietary exposure to this substance at levels of 0, 0.05, 0.5, 5 or 50 ppm for 13 weeks. Growth rate and food consumption were not affected and no clinical signs of toxicity were observed. Increased incidences of enlarged, fatty liver and decreased thymic weight were observed in the highest-dose groups of both genders; these groups also had elevated hepatic microsomal ethoxyresorufin deethylase activity and uroporphyrin. Significant increases in serum cholesterol and hepatic pentoxyresorufin dealkylase activity were observed in the highest-dose males and two highest-dose females. By contrast, liver UDP-glucuronosyl transferase activity was elevated in the two highest-dose males and the highest-dose females. Urinary ascorbic acid excretion was increased in the highest-dose males. While the amount of vitamin A was decreased dose-dependently, starting at 0.5 ppm in the liver of both sexes and in the lung of the females, the level in the kidney of the highest-dose group was increased. Administration of PCB 105 resulted in decreased dopamine in the caudate nucleus region of the brain in males and homovanillic acid in caudate nucleus and nucleus accumbens of females. Increased 5-hydroxytryptamine and 5-hydroxyindoleacetic acid were observed in the substantia nigra region of both sexes, with most of the increases being seen in highest-dose females. Anemia, characterized by decreased hemoglobin, hematocrit and red cell indices, occurred in the highest-dose group, as did eosinophilia. Treatment with PCB 105 caused dose-dependent histopathological changes in the liver and thyroid. Thymic changes were observed in the highest-dose males and two highest-dose females. Tissue residue data showed a dose-dependent accumulation of this congener in fat, liver and spleen, kidney and brain. Based on these data the no-observable-effect level of PCB 105 was judged to be 0.05 ppm or 3.9 microg kg(-1) body wt. day(-1) in males and 4.2 microg kg(-1) body wt. day(-1) in females.
Administration, Oral↗
Imaging of retroperitoneal rhabdomyosarcoma mimicking hypernephroma.
Malignant tumors that arise in the perinephric space often present a diagnostic dilemma. These retroperitoneal tumors may resemble renal carcinomas, extrahepatic lymphoma, metastatic disease, or tumors arising in other retroperitoneal organs. We present a case of a patient with a primary retroperitoneal rhabdomyosarcoma who had an extensive diagnostic workup prior to surgical intervention that was thought to be consistent with an aggressive renal cell carcinoma.
Aged↗
Plasma levels of persistent organohalogens and hormone levels in adult male humans.
In this study the authors assessed the possible relationship between high dietary exposure to persistent organohalogens (OHS) through fatty fish from the Baltic Sea and hormone levels in adult men. Blood samples were drawn from 110 men who consumed varying amounts of fish (i.e., 0-32 meals per month) for analysis of plasma levels of 18 polychlorinated biphenyl (PCB) congeners, 5 hydroxy-PCBs, 1,1,1-trichloro-2,2-bis(4-chlorophenyl)-ethane (p,p'-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE), hexachlorobenzene, and 2,2',4,4'-tetrabromodiphenyl ether. In addition, plasma levels of follicle-stimulating hormone, luteinizing hormone, prolactin, plasma thyrotropin, free and total T3, free and total T4, and free testosterone were analyzed. The authors adjusted for age, and the only significant associations that remained were negative correlations between 2,2',4,4'-tetrabromodiphenyl ether and plasma thyrotropin (p < .001), and between pentachlorophenol and follicle-stimulating hormone (p = .04). The authors expected that there would be some significant correlations that resulted from pure chance. High consumption of organohalogen-polluted fish did not appear to affect plasma concentrations of pituitary, thyroid, or testosterone hormone levels in male adults.
Adult↗
An overview of the safety evaluation of the Thermomyces lanuginosus xylanase enzyme (SP 628) and the Aspergillus aculeatus xylanase enzyme (SP 578).
Xylanases SP 628 and SP 578 were produced by submerged fermentation of Aspergillus oryzae, containing a gene code originating from Thermomyces lanuginosus and Aspergillus aculeatus, respectively. Both enzymes were subject to the same series of toxicological tests to document their safety in use. The enzymes are to be applied as processing aids in the baking industry and in wheat starch separation. Neither enzyme was found to be mutagenic in the Salmonella typhimurium reverse mutation assay, nor did they cause chromosomal aberrations in cultured human peripheral lymphocytes. No evidence of inhalation toxicity or skin and eye irritation was found. The enzymes are not regarded as skin-sensitizers, although the Buehler test with guinea-pigs revealed a minor potential. Oral administration up to 10.0 ml/kg bw/day (equivalent to a Total Organic Solids amount of 13.3% for SP 628 and of 11.3% for SP 578) in 13-week rat studies did not show any adverse effect.
Administration, Inhalation↗
Tissue distribution, metabolism, and excretion of 2,4,4'-trichlorobiphenyl (CB-28) in the rat.
The tissue distribution, metabolism, and excretion of 14C-labeled 2,4,4'-trichlorobiphenyl (CB-28) were studied in the rat. Following intravenous administration, radioactivity was removed from the blood rapidly and distributed to tissues. The time-courses of varying concentrations of CB-28 in tissues and blood were described mathematically using nonlinear regression analysis. The highest concentrations of radioactivity were found in the adipose and skin, which showed distinct uptake phases. High levels were seen at 30 minutes in liver and brain, but quickly declined. Fifty-two percent of the given dose was excreted in feces within 14 days. Intraperitoneal administration to three female rats for five consecutive days provided tissues which were analyzed for metabolites.
Animals↗
Interactions of persistent environmental organohalogens with the thyroid hormone system: mechanisms and possible consequences for animal and human health.
Several classes of environmental contaminants have been claimed or suggested to possess endocrine-disrupting potency, which may result in reproductive problems and developmental disorders. In this paper the focus is on the multiple and interactive mechanisms of interference of persistent polyhalogenated aromatic hydrocarbons (PHAHs) and their metabolites with the thyroid hormone system. Evidence suggests that pure congeners or mixtures of PHAHs directly interfere with the thyroid gland; with thyroid hormone metabolizing enzymes, such as uridine-diphosphate-glucuronyl transferases (UGTs), iodothyronine deiodinases (IDs), and sulfotransferases (SULTs) in liver and brain; and with the plasma transport system of thyroid hormones in experimental animals and their offspring. Changes in thyroid hormone levels in conjunction with high PHAH exposure was also observed in captive as well as free ranging wildlife species and in humans. Maternal exposure to PHAHs during pregnancy resulted in a considerable fetal transfer of hydroxylated PHAHs, which are known to compete with thyroxine (T4) for plasma transthyretin (TTR) binding sites, and thus may be transported to the fetus with those carrier proteins that normally mediate the delivery of T4 to the fetus. Concomitant changes in thyroid hormone concentrations in plasma and in brain tissue were observed in fetal and neonatal stages of development, when sufficient thyroid hormone levels are essential for normal brain development. Alterations in structural and functional neurochemical parameters, such as glial fibrillary acidic protein (GFAP), synaptophysin, calcineurin, and serotonergic neurotransmitters, were observed in the same offspring up to postnatal day 90. In addition, some changes in locomotor and cognitive indices of behavior were observed in rat offspring, following in utero and lactational exposure to PHAHs. Alterations in thyroid hormone levels and subtle changes in neurobehavioral performance were also observed in human infants exposed in utero and through lactation to relatively high levels of PHAHs. Overall these studies indicate that persistent PHAHs can disrupt the thyroid hormone system at a multitude of interaction sites, which may have a profound impact on normal brain development in experimental animals, wildlife species, and human infants.
Animals↗
3,3',4,4'-Tetrachlorobiphenyl. Excretion and tissue retention of hydroxylated metabolites in the mouse.
The coplanar 3,3',4,4'-tetrachlorobiphenyl (TCB) was given orally to mice and the metabolite patterns in feces, urine, liver, and adipose tissue were examined. In feces, 80% of the dose was excreted within 5 days. 5-Hydroxy-, 6-hydroxy-TCB, 4-hydroxy-3,3',4',5-tetrachlorobiphenyl, and unmetabolized TCB were identified by comparison to synthetic standards (GC/MS). 4-Hydroxy-trichlorobiphenyl and a dihydroxy-trichlorobiphenyl were indicated by the fragmentation pattern of the corresponding methylated derivatives by GC/MS. In urine, 4.9% of the TCB dose was excreted mainly as conjugates. After hydrolysis, TCB and seven hydroxylated metabolites were detected; 2-, 5-, and 6-hydroxy-TCB and 4-hydroxy-3,3',4',5-tetrachlorobiphenyl were identified and two dihydroxy-tetrachlorobiphenyls were indicated. The major compound detected after hydrolysis of urine was a dihydroxy-trichlorobiphenyl. TCB was the major compound present in the liver, while a minor portion was due to 4-hydroxy-3,3',4',5-tetrachlorobiphenyl. TCB, 4-hydroxy-3,3',4',5-tetrachlorobiphenyl, and 5- and 6-hydroxy-TCB were present in adipose tissue. In addition, radiolabeled material was present in a lipid fraction obtained after gel permeation chromatography of all samples except urine, indicating the presence of TCB metabolites with lipid characteristics.
Adipose Tissue↗
Target cells for the polychlorinated biphenyl metabolite 4,4'-bis(methylsulfonyl)-2,2',5,5'-tetrachlorobiphenyl in lung and kidney.
Light microscope autoradiography was used to determine the cellular localization of the polychlorinated biphenyl metabolite 4,4'-bis([14C] methylsulfonyl)-2,2',5-5'-tetrachlorobiphenyl ([3H]TCB) in the lung and kidney of mice and rats. Microautoradiograms prepared from thaw-mounted freeze sections showed that the radioactivity in the lung was localized in the bronchiolar lumen and epithelium. In methacrylate sections (74-82% of radioactivity extracted), a highly selective labeling was registered in the apical cytoplasm of the Clara cells. A pronounced labeling was present also in certain goblet-like cells containing periodic acid-Schiff-positive granules. Gel permeation chromatography and density gradient centrifugation showed that 80-95% of the radioactivity in lung lavage fluid was bound to a specific protein previously characterized in rat and mouse lung cytosol. The protein appeared to be enriched in the lavage fluid, as compared to lung cytosol. These data suggest that [3H]TCB binds to a protein residing in the Clara and goblet-like cells and that the labeled TCB-protein complex is subsequently secreted into the airway lumen. As shown by microautoradiography, the radioactivity in the kidney was confined to a restricted portion of the nephron, predominantly to the apical region of the proximal tubular cells.
Animals↗
From command to request: the development of language in the treatment of a symbiotic psychotic child.
A discussion of "Separation-Individuation and Transitional Objects in a Four-Year-Old Psychotic Child" by Stavroula Beratis, M.D., Robert Miller, M.D., and Eleanor Galenson, M.D. The case study of the treatment of a four-year-old symbiotic psychotic child is presented. The child is in therapy at a day treatment program at the Psychological Center of the City University of New York as part of an ongoing research program studying the relationship of cognition and object relations in autistic and psychotic children. The development of the child's language and self-concept in the course of two years of treatment is discussed. His language is regarded as an indicator of the level and quality of self-object differentiation. A distinction is drawn between the pathological symbiotic state and the normal symbiotic stage, and maturation along the lines of separation-individuation is discussed in terms of the development of dialogue.
Child, Preschool↗