A reexamination of recent publications suggesting o-toluidine may be a human bladder carcinogen.
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Carcinogens↗
Biomedical subjects
D P Anderson
Publications and source records attributed to D P Anderson.
A re-examination of the cause of excess bladder cancers in chemical plant workers.
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Aniline Compounds↗
Dietary intake of immunostimulants by rainbow trout affects non-specific immunity and protection against furunculosis.
Immunostimulant preparations Macrogard, Candida utilis, Saccharomyces cerevisiae, Evetsel, Chitosan, or FinnStim were mixed into semipurified diets and fed to groups of rainbow trout for 1 week. Fish were bled by non-lethal caudal puncture and blood samples assayed for changes in non-specific cellular immunity and humoral protein levels. In the immunostimulated fish, hematocrit levels and lymphocyte counts remained relatively stable; however, elevations were observed in oxidative radical release, myeloperoxidase activity, phagocytic indexes, and potential killing activities of phagocytic cells including neutrophils. Total plasma protein and total immunoglobulin levels were elevated by the dietary immunostimulants. A challenge with the virulent pathogen that causes furunculosis, Aeromonas salmonicida, showed that the immunostimulated groups of fish were more resistant to the disease, confirming the potential use of these substances in fish culture for the prevention of disease.
Adjuvants, Immunologic↗
Effect of soybean protein on serological response, non-specific defense mechanisms, growth, and protein utilization in rainbow trout.
Rainbow trout (Oncorhynchus mykiss) were fed chemically and immunologically defined diets containing either a low-temperature fish meal or soybean preparations containing high (SBM) or low levels of the globular antigenic proteins glycinin (G) and beta-conglycinin (BC) for 26 weeks. While trout fed both soybean preparations exhibited poorer growth than those fed fish meal, those fed the soya diet with high levels of G and BC showed the most significant growth diminution, elevated feed conversion and impaired utilization of dietary protein. Changes in intestinal morphology were also observed in fish fed the SBM diet, coinciding with the inferior nutritional performance. Several serologic and non-specific immune defense mechanisms were monitored. Cell counts showed increased leukocyte cell numbers as well as increased concentrations of plasma protein and immunoglobulin in the soya-fed fish. Increased neutrophil, monocyte and macrophage activity, as assessed by several oxidative radical production and phagocytic index assays, were higher in the soya-fed fish, possibly indicating an inflammatory or hypersensitivity response. The results of this study suggest that antigenic soya protein affects non-specific defense mechanisms, growth performance, and protein utilization in rainbow trout. Furthermore, it would appear that dietary sensitivity can be overcome by process removal of this immunologically characterized antigen in soybean protein. Serological and immunological assessments appear to be very useful criteria for evaluating various protein sources for fishes.
Animals↗
Photophobia and cortical visual impairment.
Photophobia, or intolerance of light, is not completely understood as a symptom. It has been divided into ocular and central types. This study shows that persistent, usually mild, photophobia occurs in about one-third of children with cortical visual impairment (CVI). When the CVI is congenital the photophobia is present from birth, and when it is acquired the sensitivity to light appears immediately after the brain insult. The intensity of photophobia tends to diminish with time and occasionally it may even disappear. The pathophysiology is unclear, as in all other neurological disorders associated with photophobia.
Brain↗
In vitro antigen trapping by gill cells of the rainbow trout: an immunohistochemical study.
An in vitro assay was used to study the involvement of gill cells in the trapping and processing of particulate antigens. Gills were routinely processed for light microscopy after being placed in medium containing either Yersinia ruckeri O-antigen-labelled fluorescent beads, unlabelled fluorescent beads, Y, ruckeri O-antigen or formalin-killed Y. ruckeri, for 0, 30 s, 1, 5 and 30 min. Y. ruckeri formalin-killed cells, Y. ruckeri O-antigen and fluorescent beads labelled with Y. ruckeri O-antigen were taken in by gill epithelial cells as soon as 30 s after administration. In contrast, unlabelled fluorescent beads adhered to the epithelial cell membranes, but did not occur inside the gill cells. These results are discussed principally in relationship with the specificity of antigen trapping.
Animals↗
Neutrophil, glass-adherent, nitroblue tetrazolium assay gives early indication of immunization effectiveness in rainbow trout.
Neutrophil activity in rainbow trout (Oncorhynchus mykiss) is increased upon antigenic stimulation with the Yersinia ruckeri O-antigen bacterin. The characteristics of neutrophil attachment to glass and nitroblue tetrazolium (NBT) staining were used to determine the effectiveness of immunization programs with fingerling rainbow trout. Fish immunized by intraperitoneal injection with doses of 100, 10, or 1 microgram of the bacterin showed the highest responses in that order in numbers of glass adherent, NBT-positive neutrophils. Studies on the kinetics of the occurrence of numbers of glass-adherent, NBT-positive staining cells from the fish injected with the 10 micrograms dose showed the numbers of positive cells were largest on Day 2 after injection. The specific immune response was confirmed by demonstrating the presence of plaque-forming cells by the passive hemolytic plaque assay and the rise in humoral antibody titers by passive hemagglutination 12 days after injection. The effects of immunization in trout could be detected earlier by using the neutrophil glass adherence and NBT reduction assays than by using assays based on observations of the specific immune response.
Animals↗
Immunostimulants added to injected Aeromonas salmonicida bacterin enhance the defense mechanisms and protection in rainbow trout (Oncorhynchus mykiss).
Immunostimulants were given to rainbow trout for assaying effects on modulating non-specific defense mechanisms, specific immune response, and protection levels against pathogen challenge with Aeromonas salmonicida. Three drugs, levamisole (an approved veterinary drug in the USA), a quaternary ammonium compound (QAC), and a short-chain polypeptide (ISK) were found to affect the non-specific defense mechanism activities, which were measured by changes in circulatory neutrophil and phagocytic activity levels, and the specific immune response factors, which were measured by numbers of plaque-forming cells, and circulatory antibody levels. When given alone, the immunostimulants elevated the non-specific factors. When injected in combination with an A. salmonicida O-antigen bacterin, the non-specific factors were further elevated, and the specific response was raised over samples taken from fish given the bacterin without the immunostimulants. Challenge tests with the virulent pathogen, A. salmonicida, showed a 5-6 day delay in the onset of mortalities in the fish given the immunostimulants alone, and a 12-14 day delay when immunostimulants given were combined with the bacterin. In the groups given the QAC or ISK with the bacterin, there was a 20% and 40% survival rate, respectively.
Adjuvants, Immunologic↗
In vitro effect of levamisole on the neutrophil activity in rainbow trout (Oncorhynchus mykiss).
An in vitro immunization and cultivation method for fish spleen organ section was used to investigate the effects of levamisole on the neutrophil activity. After 10 days of culture with either 50 micrograms/ml, 25 micrograms/ml, 5 micrograms/ml or no levamisole in the media, the nonspecific defense reactions were measured by determining the metabolic activity of neutrophils by using the nitroblue tetrazolium test, and phagocytic and adherence indexes by incubating the fish cells with suspensions of formalin-killed Staphylococcus aureus. Elevations were found in nonspecific cellular defense in the 5 micrograms/ml levels of levamisole. The 25 micrograms/ml levels instigated a slight elevation in nonspecific cellular defense and the 50 micrograms/ml levels suppressed all indicators, whether levamisole was given alone or combined with Yersinia ruckeri O-antigen or DNP-Ficoll. These antigens are themselves nonspecific cellular defense stimulators, and a synergistic effect was evident when combined with 25 micrograms/ml and 5 micrograms/ml levels of levamisole.
Animals↗
In vitro immunostimulation of rainbow trout (Oncorhynchus mykiss) spleen cells with levamisole.
An in vitro immunization and cultivation method for fish spleen organ sections was used to investigate the effects of levamisole on the immune response. After 10 days of culture with either 50 micrograms/ml, 25 micrograms/ml, 5 micrograms/ml or no levamisole in the media, the nonspecific defense reactions were measured by determining the metabolic activity of neutrophils by using the nitroblue tetrazolium test, and phagocytic and adherence indexes by incubating the fish cells with suspensions of formalin-killed Staphylococcus aureus. The specific immune system activity was shown by the passive hemolytic plaque assay demonstrating the numbers of antibody-producing cells. Elevations were found in nonspecific defense and specific immune response in the 5 micrograms/ml levels of levamisole. The 25 micrograms/ml levels instigated a slight elevation in some nonspecific levels but showed suppression in the specific immune response. The 50 micrograms/ml levels suppressed all indicators whether levamisole was given alone or combined with Yersinia ruckeri O-antigen or DNP-Ficoll. These antigens are themselves nonspecific defense stimulators, and a synergistic effect was evident when combined with 25 micrograms/ml and 5 micrograms/ml levels of levamisole.
Animals↗
Comparisons of nonspecific and specific immunomodulation by oxolinic acid, oxytetracycline and levamisole in salmonids.
Oxolinic acid, a promising drug for the treatment of bacterial fish disease agents, was tested for possible immunomodulatory effects on fish. Another antibiotic oxytetracycline, known to be immunosuppressive at higher treatment doses, and levamisole, a known immunostimulator for higher vertebrates, were also compared for causing changes in the nonspecific defense compartment and the specific immune system in rainbow trout. Groups of fish were immunized with Yersinia ruckeri O-antigen bacterin in combination with selected doses of the drugs. The nonspecific defense activity was measured by demonstrating neutrophil metabolic activity by the nitroblue tetrazolium assay, by counting engulfed bacterial cells for a phagocytic index and by counting leukocytes with adherent bacterial cells for the adherence index. The specific immune response was monitored by the passive hemolytic plaque assay demonstrating the numbers of antibody-producing cells. The results showed that oxolinic acid, used at recommended doses for the treatment of bacterial diseases, did not cause immunosuppression in either the nonspecific defense or specific immune system compartments, whereas tetracycline at 10 mg/kg caused reduced activity in both. Fish given levamisole injections before the antigen injection showed a stimulated nonspecific defense but a much reduced specific immune response.
Adjuvants, Immunologic↗
Vitamin A concentrations in liver determined by isotope dilution assay with tetradeuterated vitamin A and by biopsy in generally healthy adult humans.
The vitamin A status in 11 generally healthy surgical patients was estimated by measuring the dilution of a 45-mg oral dose of tetradeuterated retinyl acetate (99% pure). After purification of retinol by high-performance liquid chromatography, the ratio of 2H4-retinol:1H-retinol in plasma was measured by gas chromatography-mass spectrometry. On the basis of the observed ratios of [2H4]retinol:[1H]retinol over 19-47 d, the total body reserves and liver concentrations of vitamin A were calculated. Liver biopsy samples taken at surgery were directly analyzed for vitamin A. The correlation coefficient between calculated and measured liver vitamin A concentrations for 10 of the subjects was 0.88, and the Spearman's rank correlation coefficient was 0.95 (p less than 0.002). Thus, total body reserves of vitamin A in humans can be estimated validly in the marginal and satisfactory ranges by a benign, relatively noninvasive procedure.
Adult↗
Methylmercury and the health of autochthons in northwest Quebec.
We conducted a cross-sectional epidemiologic and clinical study to evaluate the nature, magnitude, and frequency of unfavourable health states among residents of northwest Quebec. Of particular interest were the possible occurrence of Minamata disease and any other neurological abnormalities. We also sought to determine whether industrial or naturally-occurring mercury in the region's environment were causally associated with any disorders that might be detected. A total of 321 subjects were studied in four groups with contrasting exposure to point-source mercury from a chlor-alkali plant in the area. Methylmercury in hair served as the marker of subject's ingestion of any organic mercury (natural or industrial). Ten pre-chosen target variables, seven clinical and three neurophysiological, were assessed in all subjects. Relationships between mercury in hair and each target variable were calculated. We determined whether gradients in target variables corresponded to gradients in potential exposure of the subjects to the aquatic emissions of the chlor-alkali plant. Minamata disease was not found. Diabetes and alcohol-related health problems assessed as important clinically plausible confounders, were common. Differences in frequency or magnitude of clinical, toxicological, and physiological findings among the contrast groups were small and not of clinical or statistical significance. There were definite relationships between mercury in hair and four target variables despite the low values of mercury measured and the mild nature of the health problems observed. This would suggest that verifiable biological threshold levels for clinical effects, if such exist, may be substantially lower among Canadians than those currently adopted as policy for adults elsewhere. A gradient was found only for two of the ten target variables. Clinically meaningful alternate hypotheses for observed health effects emerge in the data and agree with observations in the field made by consulting clinical experts.
Animals↗
Water imbibition in the rat prostate during castration-induced regression.
The present study was conducted to examine changes in water concentration in the ventral prostate of adult rats at different intervals following castration. The prostatic dry weight was obtained by drying the fresh prostate at 70 degrees C for at least 110 hr and the prostatic water content was calculated from its wet and dry weight. Under normal conditions, the prostatic water concentration ranges from 81.9 to 82.7% in uncastrated rats. The prostatic water concentration started to increase at 8 hr postcastration (83.1%) but this increase was not statistically significant. By 16 hr postcastration, the prostatic water concentration (83.8%) became significantly higher than that of the uncastrated animals. In rats of day 1 to day 10 postcastration, the prostate contained significantly more water (84.4%-84.7%) than those in uncastrated animals. By day 21 postcastration, the prostatic water concentration (81.5%) was not significantly different from that of uncastrated rats. Unlike the prostate, the skeletal muscle did not significantly change the water concentration following castration. The 51Cr-EDTA space in the prostate was not significantly different in rats before and after castration. These results indicate that water imbibition in the rat prostate is associated with an active period of prostatic regression and that the change in the 51Cr-EDTA space during prostatic regression is not the major cause of water imbibition in the tissue. Therefore, the present findings suggest that castration-induced water imbibition in the rat prostate is caused by an increase in the intracellular water space.
Adrenalectomy↗
Immunization and culture of rainbow trout organ sections in vitro.
Splenic and anterior kidney sections or whole organs were excised from large (1 kg) or small (200 g) rainbow trout (Salmo gairdneri) and placed in sterile 60 mm plastic plates containing 10 ml of Eagle's minimal essential medium (EMEM) supplemented with normal or fetal calf serum for in vitro culture. The organ samples were immunized in vitro by direct injection or by mixing in the medium Yersinia ruckeri O-antigen or dinitrophenyl-Ficoll. The medium was changed once during the 10-day incubation at 15 C. The passive hemolytic plaque assay demonstrated antibody production from the plaque-forming cells (PFC); passive hemagglutination was used to measure antibody titers in the media. High numbers of PFC occurred in cultures of either kidney or spleen, demonstrating that these organs can function independently for antibody production. Splenic sections from large fish produced more PFC than comparable whole organs from small fish. EMEM supplemented with 2% normal calf serum was a satisfactory culture medium. 2-hydroxyethyl-mercaptan an ingredient used in mammalian cell culture, inhibited antibody production in trout cells. These techniques are being used in the culture of organs and cells to elucidate pathways and sequences of antigen uptake and delivery of the immunopoietic tissues in trout.
Animals↗
Effect of exogenous corticosteroids on circulating virus and neutralizing antibodies in striped bass (Morone saxatilis) infected with infectious pancreatic necrosis virus.
Corticosteroids have been reported to induce immunosuppression in fish exposed to many types of bacterial antigens. We document a similar phenomenon in fish exposed to infectious pancreatic necrosis virus (IPNV). Fingerling striped bass that were injected with the steroid triamcinolone acetonide (100 mg/kg body weight) 24 hours before receiving intraperitoneal inoculation with IPNV became viremic 3 days post inoculation (dpi) and virus was still detected in the buffy coat cells 14 dpi. In contrast, viremia could not be detected after 7 dpi in fish that received virus but not steroids. Circulating virus neutralizing antibodies were first detected in steroid treated fish at 10 dpi compared to 7 dpi for the virus injected fish and titers were consistently lower in the steroid group. Steroid treatment of chronic IPNV-carriers did not induce detectable viremia nor alter circulating antibody levels in chronic IPNV-carriers. None of the striped bass demonstrated clinical signs of viral disease.
Animals↗
Visual abnormalities with multiple trauma.
The diversity of pathogenetic mechanisms involved in posttraumatic visual impairment was reviewed in a study of the hospital records of 24 patients admitted with multiple injuries. Most major visual abnormalities occurred in young people (average age 33 years) who presented with a wide range of overall severity of injury (injury severity score 13-47) and involvement of the central nervous system (Glasgow coma scale 5-15). Bilateral or monocular blindness developed in 63% of patients. Seventy percent of the injuries involved the anterior visual pathways with damage to the optic nerve alone accounting for 35%. Fractures of the sphenoid bone, particularly of the body, accompanied optic nerve and chiasmal injuries and some cases of traumatic carotid-cavernous fistulas. Pathogenetic mechanisms varied according to the site of injury and included vitreous hemorrhage and optic atrophy secondary to raised intracranial pressure, retinal hypoxia from carotid-cavernous fistulas, shearing and compression injuries of the optic nerve, traumatic chiasmal syndrome, temporoparietal and occipital contusions, and transtentorial herniation with occipital infarction. Visual abnormalities varied in severity from moderately reduced visual acuity and diverse hemianopias and scotomas to blindness. The incidence of posttraumatic residual visual abnormalities is likely to increase in the wake of improved acute care of the traumatized victim.
Adolescent↗
Molecular analysis of the lymphocyte membrane.
Methods for the molecular analysis of lymphocyte membranes are reviewed briefly, and wherever possible presented in a manner relevant to comparative studies. The specific areas reviewed include the bulk isolation of lymphocyte membranes, the use of radioisotopes to covalently label lymphocyte membrane molecules, the use of lectins to characterize membrane glycoconjugates, and our current understanding of lymphocyte membrane immunoglobulins.
Animals↗