bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Medizin und das „Größere Deutschland”︁: Kolonialpolitik und Tropenmedizin in Deutschland, 1884–1914
Authors: Eckart Wolfgang U.
Published: October 2006

When Imperial Germany entered the group of European colonial powers in 1884, among her enthusiastic physicians the question arose how the white man, as a representative of a vulnerable race, could be able to exist permanently in tropical regions. It is not surprising that German colonial circles especially the representatives of the organized German colonial movement were taking a keen interest in the same question. The Deutsche Kolonialgesellschaft (German Colonial Society) inaugurated and financed international questionaire‐activities in the field of tropical medicine with the intention of supporting the institutionalization of this new medical discipline. In fact, the foundation of the Hamburg Institut für Schiffs‐ und Tropenkrankheiten in 1901 was not only a consequence of the specialisation of bacteriology but also an expression of the grasp of colonial politics for tropical medicine as an instrument of colonization. Ever since up to the loss of the imperial Schutzgebiete (protectorates) German tropical medicine has been in a very close connection with colonial politics. Its tasks ranged from the organization of medical infra‐structures at the colonial periphery to the delivery of instruments for the imperial process of acculturation or the supply with pseudo‐scientific arguments for racial discrimination. The spectrum of these tasks will be outlined in this paper, and the interdependency of German colonial politics and German colonial medicine will be discussed.
Ferdinand von Richthofen als Erforscher Chinas. Ein Beitrag zur Entstehung und Verarbeitung von Reisebeobachtungen im Zeitalter des Imperialismus
Authors: Wardenga Ute
Published: October 2006

This contribution is focussed on origin and digestion of voyage‐observation during the age of imperialism. Interpretation of Ferdinand von Richthofen's diary notes taken of his voyages through China (1868–1872) makes evident, that a gradual chance of contents of his observations had taken place. A merely imperialistic formulation of the questions at the beginning progrades towards an approach to understand land and people.

A comparison of this observation contents with later publications of Richthofen about China shows, that they were again changed under the auspices of German imperialistic politics in favour of far‐reaching geopolitical speculations. This change takes place within the scientific community, where Richthofen had made a career by then. Amongst others the reason was to consolidate the newly established discipline of geography at German universities. Richthofen's geopolitical speculations thus formulated became the base for the occupation of the bay of Kiautschou by German forces during 1897.
The Indo‐European Telegraph System 1868–1931: Politics and Technical Change
Authors: Fuchs Margot
Published: October 2006

Die Technikgeschichte der telegraphischen Überlandverbindung zwischen London und Kalkutta konzentrierte sich bisher zumeist auf den Bau der Linie. In dieser Arbeit liegt der Schwerpunkt auf der Entwicklung der Telegraphenapparate und dem Versuch, die ‘automatische’ Sendeweise einzuführen.
Der Naturwissenschaftler und sein Körper. Naturwissenschaftsgeschichte aus anthropologischer Perspektive
Authors: Kutschmann Werner
Published: October 2006

Since it's early days modern science is confronted with the following dilemma: Scientific investigation of nature requires the availability of the scientist's body in nearly all of its activities, though on the other hand science feels obliged to minimalize any influence of this body for methodological reasons. How has science dealt with this dilemma? How has it managed to keep the balance between using the body in favour of knowledge and keeping the required distance to it? In answering these questions the paper tries to reconstruct the history of early modern science from an anthropological perspective.
Briefe im 19. Jahrhundert als wissenschaftshistorische Quelle. Dargestellt am Beispiel des Briefwechsels des Apothekers A. P. J. Du Menil (1777–1852)
Authors: Friedrich Christoph
Published: October 2006

The aim of this article is to demonstrate the importance of scientific communication of pharmacists in the 19th century. 89 letters were analysed both written received by August Peter Julius Du Menil (1777–1852). In the paper also a summary is given about the importance of extensive activity of the pharmacist Du Menil. He was be in correspondence with 39 scientists, for instance 13 physicans and 12 pharmacists. The letters are an interesting document about scientific community in the 19th century.
Die Berechnung von Wasserfluten. Tideforschung in den Niederlanden, 1920–1960
Authors: van Den Ende Jan , De Jong Frida
Published: October 2006

In the first half of this century a computing problem became evident in the course of preparatory research for major hydraulic projects in the Netherlands. One of the most novel problems was to predict the changes in the tidal movements caused by hydraulic works in coastal waters. Between 1920 and 1960 several solutions were proposed and put into practice: numerical methods, contracting young men for the calculations, analogue electronical networks and large scale models. The amount of computing labour played a decisive part in the choice between these methods. After a storm surge in 1953 causing estensive inundations in the southern part of The Netherlands, the requirements of the Delta Works project gave an enormous impetus to all three types of methods.
Lügen ist überhaupt das Kennzeichen unserer. Zeit Über einen unveröffentlichten Briefwechsel zwischen Max Born und Friedrich Herneck
Authors: Wessel Karl‐Friedrich , Koch Martin
Published: October 2006

The East Berlin marxist Friedrich Herneck and Max Born, Nobel Price winner in physics, exchanged more than 140 letters in the years between 1958 and 1970. In the beginning they discussed problems of the history of science, especially Born's personal memories of the development of physics in the 20th century. In later years they discussed political and social problems too. Only in these letters Born expressed clearly his attitude to communism and the social system of East Germany.
Treatment of experimentally induced Lantana poisoning in sheep
Authors: McSweeney Christopher S. , Pass Michael A.
Published: October 2006

Lantana poisoning was induced in sheep by giving 4 g kg−1 Lantana camara orally. When the contents of the rumen were removed from sheep three or six days after giving them lantana and placed into the empty rumens of normal sheep, the recipient sheep became intoxicated. Administration of purgatives such as raw linseed oil or Glauber's salts orally, or administration of bethanechol subcutaneously failed to stimulate rumen motility in lantana poisoned sheep and are therefore unlikely to be effective in eliminating residual toxin from the rumen. Intravenous administration of a multiple electrolyte solution to lantana poisoned sheep improved rumen motility, and motility was increased even more when 2–3 1 of freshly collected rumen liquid was given orally to rehydrated animals. However, these treatments did not restore motility to normal and animals treated by these methods did not survive the intoxications. The effect of manually removing the rumen contents from sheep with lantana poisoning was studied in sheep with chronically‐implanted rumen cannulae. When the rumen contents were removed from sheep three days after lantana was given and replaced with fresh rumen contents or a multiple electrolyte solution, there was a significant increase in survival compared with untreated sheep. Removal of rumen contents at six days and replacement with fresh rumen contents or simulated rumen contents containing a buffered mixture (pH 6.7, ‐ 330 mV) of lucerne and rumen liquid, also significantly increased survival, but replacement with a multiple electrolyte solution did not. It is concluded that lantana poisoning can be treated by removing the residual toxin from the rumen and re‐establishing rumen fermentation.
Acute toxicity of some alkylaminocyclohexane carbonitriles, probable contaminants of phencyclidine analogs
Authors: Clark C. Randall , Wall George M. , Davidson Priscilla P.
Published: October 2006

The acute toxicities of seven alkylaminocyclohexanecarbonitriles, probable contaminants of Phencyclidine analogs, were investigated in Swiss male mice and i.p. LD50 values were obtained. The LD50 value of each nitrile was significantly increased (two‐ to three‐fold) using sodium nitrite pretreated mice.
Acrylonitrile solubility in human blood: Determination of the Ostwald partition coefficient
Authors: Cheng L. , Jaeger R.
Published: October 2006

An in vitro head space method was used to determine the Ostwald partition coefficient (OPC) of acrylonitrile in the following liquids: lactated Ringer's solution, fresh rat blood, fresh human blood, outdated human blood and cellular fractions of either fresh or outdated human blood. Fresh human blood cells have the strongest affinity for acrylonitrile (OPC >700). Fresh whole human blood has a lower OPC, approximately 500. Lactated Ringer's solution, outdated human blood and water had lower OPC values, approximately 200.
Tissue distribution and metabolism of O‐(4‐methoxyphenylcarbamoyl)‐3‐diethylaminopropiophenone oxime hydrochloride (USVP‐E142) in the rat
Authors: Gollamudi Ramachander , Glassman Jerome M.
Published: October 2006

The disposition of 0‐(4‐methoxyphenylcarbamoyl)‐3‐diethylaminopropiophenone oxime‐(carbonyl)‐14C hydrochloride in the rat was studied in vivo and in vitro. Upon oral administration, radioactivity was detected within 15 min in many tissues, including the brain. The lung and the liver had the highest levels. The first‐order rate constant for the disappearance of 14C from the stomach was 8.2 × 10−3 min−1 for fasted and 5.7 × 10−3 min−1 for non‐fasted rats. Most of the radioactivity was eliminated in the form of 14CO2. The major metabolic pathway appears to be the hydrolysis of the carbamoyl bond followed by decarboxylation of the resultant carbamic acid, leading to the liberation of CO2. Bis(p‐methoxyphenyl)urea and 3‐diethylamino‐4′‐hydroxypropiophenone were identified as urinary metabolites.
Platinum determination in plasma and urine by flameless atomic absorption spectrophotometry
Authors: Cano J. P. , Catalin J. , Bues‐Charbit M.
Published: October 2006

A method is described for the measurement of total platinum in plasma and urine, using flameless atomic absorption spectrophotometry, which is sensitive and reproducible enough to permit pharmacokinetic studies on cis‐dichlorodiammineplatinum(II). The plasma platinum concentrations are determined after ten‐fold dilution in 0.5% nitric acid, and urine is analysed after twenty‐fold dilution in distilled water. The use of tantalized‐treated graphite furnaces prior to each dosing series allows one to increase the sensitivity and reproducibility of measurements. A comparative study made on the classic method, which consists of introducing samples manually, and an original automatic one, confirms the latter's superiority. By taking ten measurements, the reproducibility of the injections is 1.89% for calibration points containing 100 ng ml−1 of platinum and is 2.47% for those containing 35 ng ml−1 of platinum. The reproducibility of the method was determined on plasma samples to which cis‐DPP had been added, using an automatic sample injection system. It varies between 4.73% and 2.93% for platinum concentrations between 0.32 μg ml−1 and 2.61 μg ml−1. This represents the range of the concentrations observed in the kinetic studies. The absolute detection limit of platinum is 10 ng ml−1.
Naloxone treatment of acute alcoholic or benzodiazepine intoxication
Authors: Malizia E. , Cerbo R. , Ambrosini M. , Russo A. , Smeriglio M.
Published: October 2006

Naloxone (0.8–1.6 mg i.v.) effectively counteracted the clinical signs associated with benzodiazepine intoxication in 9 out of 10 emergency room patients. Naloxone (0.8–2.8 mg i.v.) also favorably influenced the state of consciousness in 9 out of 9 alcohol‐intoxicated patients. In cases of acute narcotic overdose, the action of naloxone is almost immediate. Since a longer time was required for naloxone to counteract benzodiazepine or alcohol intoxication, the mechanism of action may be different from that implied in narcotic overdose. In the present cases, naloxone may have acted directly on the respiratory or consciousness centres of the brain.
Inorganic lead in man's environment: Sources and toxicological significance
Authors: Hammond P. B.
Published: October 2006

Major anthropogenic sources of lead in the general population are solder in canned foods and lead in air, originating from auto emissions and various industrial sources. In the US, approximately ten percent of total dietary lead originates from solder. The contribution of airborne lead to total daily lead absorption varies with air lead concentration in a non‐linear fashion. Incremental rise in blood lead concentration decreases progressively with increasing air lead concentration and with the magnitude of blood lead concentrations derived from other sources. Hand‐to‐mouth transfer of lead from dust is a significant added source of lead in young children. Ingestions of flakes and chips of paint is probably still a significant problem when blood lead concentrations are grossly elevated. The major unresolved issue as to toxic effects in children concerns subtle neurobehavioral deficits. As yet, there is no clear knowledge as to the degree of exposure which causes these effects, nor as to the importance of age and duration of exposure as determinants of sensitivity. Occupational exposure, even at relatively moderate levels, causes a decrement in hemoglobin concentration, and reduction in the functional reserve of the kidneys. Recent studies conducted by two groups of investigators in the US indicate that a substantial number of workers in lead smelters have substantial loss of glomerular function as determined by renal clearance of inulin or iothalamate. This effect is probably due to a reduction in renal blood flow. It is most pronounced with long‐term exposure.
Mycotoxin surveillance in Australia
Authors: Blaney B. J.
Published: October 2006

The occurrence of mycotoxicoses in Australia has been reviewed with an emphasis on cases of aflatoxicosis. Most surveys for aflatoxins in feedstuffs have concentrated on obviously mouldy material, or peanut by‐products, which appear to be the most frequently contaminated in Australia. Aflatoxins have been detected in most agricultural products. Ochratoxin and zearalenone are produced by Australian fungal isolates, but little information has been obtained on the field occurrence of these or other mycotoxins. The history of efforts by various food production industries to eliminate aflatoxins from their products is traced, as is the progress of formulation of regulations to limit aflatoxin concentrations in human foods and animal feeds. It is suggested that some exposure of humans to mycotoxins may arise from situations of mould growth in foods at the retail level or in the consumer's home, and thus be largely beyond the control of present surveillance methods.
Ecotoxicology of petroleum hydrocarbons in the marine environment
Authors: Miller J. G.
Published: October 2006

The utilization of petroleum resources as an energy source for society results in the global discharge of significant quantities of petroleum hydrocarbons into the marine environment (about 6 × 106 tonnes per year). Consequently, there is a need to evaluate the ecological impacts of petroleum in the marine environment and to identify the scope and dimensions of resultant impacts. Currently, a substantial body of diverse and largely unco‐ordinated information on the effects of petroleum discharges in marine environments is available in the scientific literature. The application of an ecotoxicological approach, however, allows the development of critical evaluation models and frameworks which attempt to integrate and apply general principles of toxicology and ecology to a synthesis of the available information on effects induced by petroleum hydrocarbons in the marine environment. These aspects are discussed in relation to the significance of sub‐lethal and lethal concentrations of petroleum hydrocarbons (e.g. aromatic fractions) within marine ecosystems.
Increase in urinary porphyrin excretion in workers exposed to polychlorinated biphenyls
Authors: Colombi A. , Maroni M. , Ferioli A. , Castoldi M. , Jun Liu Ke , Valla C. , Foà V.
Published: October 2006

Urinary porphyrin excretion was investigated in 67 workers occupationally exposed to commercial mixtures of polychlorinated biphenyls (PCBs) by determining the concentration of uro‐, hepta‐, hexa‐, penta‐, and coproporphyrin homologues. The workers had a mean blood PCB concentration of 386 ± 257 ppb (mean ± SD; range 162–1319 ppb). These values are at least ten‐fold higher than that expected in a population not occupationally exposed to PCBs. No qualitative alterations of the urinary porphyrin excretion were found and the uroporphyrin: coproporphyrin ratio remained normal. There was a definite increase in the excretion of all the porphyrinic homologues, so that the average concentration of total porphyrins in urine was 94.5 μg 1−1 in the exposed group versus 48.3 μg 1−1 in the control group. This excretory pattern of porphyrins corresponds to that usually observed in the first stage of chemical porphyria induced by polyhalogenated aromatic hydrocarbons. In accordance with current knowledge, this should be interpreted as a consequence of the specific inductive properties of PCBs on liver microsomal enzymes. The results of this investigation show that, as already observed in experimental animals, commercial mixtures of PCBs have a porphyrinogenic activity in man, as well.
Erythrocytic δ‐aminolevulinate dehydratase activity as a function of pH. A study of activity ratios as biologic indicators of lead intoxication
Authors: Wigfield D. C. , Farant J.‐P.
Published: October 2006

The use of ratios of erythrocytic δ‐aminolevulinic acid dehydratase activity measured at specific pH values, with or without prior incubation of the buffered hemolysate, was investigated as a possible alternative to the measurement of enzyme activity at a single pH value as a biologic index of lead intoxication. Tests conducted with lead‐intoxicated rabbits have shown that activity ratios are simpler to perform, have remarkable stability over extended periods of blood storage, afford excellent linear correlation with blood lead concentrations, and show less individual‐to‐individual scatter than results obtained with the former assay. Although the ratios are specific for lead in the presence of cadmium, mercury, carbon monoxide or ethanol, this specificity is suspect if concurrent excessive exposure to copper or zinc takes place. In the absence of such occurrences, the activity ratios can be considered as reliable and diagnostically valid screening tests for monitoring the effects of chronic lead absorption.
Changes in ultrastructure and subcellular mercury distribution in rat liver after separate and combined administrations of mercuric mercury and selenite
Authors: Miura Kyoko , Imura Nobumasa
Published: October 2006

The ultrastructural changes and the subcellular mercury distribution in the liver of rats, which were injected with HgCl2 and/or Na2SeO3, were studied using electron microscopy and electron microscopic histochemical methods. Mercuric chloride (10 μmol per kg body weight) caused heavy cell damage both in hepatic parenchymal cells and in reticuloendothelial cells. Selenite (10 μmol per kg body weight) simultaneously administered had little influence upon the morphological feature of hepatic injury caused by mercuric chloride. However, the density of fine gold grains, which display the mercury deposits, appeared to be higher in the livers of rats treated with mercury plus selenite than in those administered mercury alone. In both groups of rats (those which received mercury alone and those which received mercury plus selenite), mercury was predominantly deposited in Kupffer cells and localized in lysosomal dense bodies. Also, in hepatic parenchymal cells, mercury was mainly deposited in the lysosomal dense bodies neighbouring bile canaliculus, although the level of mercury estimated by the density of gold grains seemed to be lower than that in Kupffer cells.
Urinary mercury excretion in the early phase of mercury vapor exposure in rabbits
Authors: Ishihara Nobuo , Nakaaki Kenji , Satoh Hiroshi , Sasaki Akihiko , Yamamoto Reiko , Miyasaka Yoshinori , Urushiyama Kenji , Suzuki Tsuguyoshi
Published: October 2006

Rabbits were exposed to mercury vapor at concentrations from 0.03 to 10 mg Hg m−3 for 3 and 8 h. Mercury concentrations in urine, red blood cells and plasma, activities of several enzymes in urine, urinary protein and creatinine concentrations, and catalase activities in red blood cells were determined before and during the exposure. During latent periods for the detection of mercury after the start of exposure in urine, red blood cells or plasma showed an inverse correlation with the level of mercury in the inspired air. When the air mercury level was 1.5 mg Hg m−3 or below, mercury was not detected in plasma, in spite of a clear rise of urinary and erythrocytic mercury levels in the early time period during exposure. However, with air mercury higher than 2 mg Hg m−3, mercury was detected in urine, red blood cells and plasma. Urinary protein, urinary enzyme activities and blood catalase were unaffected during the course of exposure.
The presence of trihalomethanes in soft drinks
Authors: Abdel‐Rahman Mohamed S.
Published: October 2006

When chlorine is employed as a surface disinfectant, the chlorinated organic compounds ‘trihalomethanes’ are formed from the interaction of chlorine with various organic substances in the water. Epidemiological studies have demonstrated the association between increased cancer mortality and high concentrations of trihalomethanes. The soft drink industry has been using granular activated carbon (GAC) to eliminate chlorine and trihalomethanes in water processing for many years. Studies were conducted to determine the quantity and quality of trihalomethanes in the soft drinks. The total trihalomethanes concentration was highest in the Colas and lowest in Sprite and 7 Up. It is hypothesized that this variation is due to the method of Coca extraction and the presence of caramel.
Unscheduled DNA synthesis detection and metaphase analysis in a common test system in vivo — in vitro
Authors: Skinner Michael J. , Schreiner Ceinwen A. , Davis Frank T.
Published: October 2006

The induction of clastogenic events in vivo is easily detected by using bone marrow metaphase analysis. We have previously shown that it is possible to detect unscheduled DNA synthesis (UDS) by culturing the lymphocytes of animals treated in vivo in the presence of 3H‐thymidine ([3H]dThd). Rats were treated orally with cyclophosphamide (25, 50 and 75 mg kg−1) or 2‐acetamidofluorene (10, 20 and 30 mg kg−1) suspended in Methocel® K4M Premium or with vehicle (10 ml kg−1). Five rats per group received a single dose, and peripheral blood obtained from each rat was maintained in culture with [3H]dThd. Radioautography was used as the indicator system for UDS, and bone marrow cells arrested at metaphase were examined for clastogenic events. The slides were coded and read blind to eliminate bias. A minimum of 500 cells and 50 cells were scored per rat for UDS and clastogenicity, respectively. A significant, dose‐related increase in UDS was observed in animals from both test groups and there was a significant increase in clastogenicity in the cyclophosphamide‐treated animals. The utility of one test animal for several mutagenicity tests to incorporate in situ metabolic biotransformation and yield more comparable data is supported by this work. We feel the combination of UDS and metaphase analysis in a common test animal will enable investigators to measure more closely several types of genotoxic activity induced by a single compound.
Nasal reflexes: Reduced sensitivity to CO2 irritation in cigarette smokers
Authors: Dunn Jan D. , Cometto‐Muniz J. Enrique , Cain William S.
Published: October 2006

Carbon dioxide inhaled through the nose in concentrations above 10% evokes nasal irritation. As concentration is increased, a non‐systemic, reflexive interruption of inhalation eventually occurs in most persons. This study revealed that smokers have a considerably higher threshold for the reflex. The elevation of threshold occurred to a comparable degree in both male and female smokers, although females generally had a lower threshold than males. It therefore appears that smokers have less sensitivity to nasal irritants. This marks the first instance of a substantial chemosensory difference between smokers and non‐smokers.
Conversion rate of non‐chelatable to chelatable lead after CaEDTA injection: A kinetic study in two lead workers
Authors: Arak Shunichi , Murata Katsuyuki , Yokoyama Kazuhito , Aono Hiroshi , Yanagihara Susumu , Ushio Koichi
Published: October 2006

Diminution rate of body burden of chelatable lead (CPb) after injection of calcium disodium ethylenediamine tetraacetate (CaEDTA) was estimated at between 0.7 and 0.4% per week in two lead workers after termination of lead exposure. Hence, alteration in body burden of CPb during the week after a single injection of CaEDTA was simulated by two different equations. The first equation was (1 + α−1.3β)6 (1–1.03k + α) A = 0.993A or 0.996A, where A = body burden of CPb just before CaEDTA injection; α = proportion of CPb converted from non‐chelatable lead (NPb) to A during the 24 h after CaEDTA injection; k = proportion of 24‐h mobilization yield of lead by CaEDTA to A; and β = proportion of 24‐h spontaneous urinary lead excretion to A. This equation was based on the assumption that the amount of lead converted to CPb during 24 h was proportional to the initial level of CPb. The second equation, i.e. (1–1.03k) (1–1.3β)6 A + {(1–1.3β)6 + (1–1.3β)5 + … + (1–1.3β) + 1} αA = 0.996A or 0.996A, assumed that the amount of lead converted to CPb during 24 h was nearly constant during a week after CaEDTA injection. The conversion rate (α) was obtained as a solution of each equation after determination of k and β according to our model. It was estimated that the amount of lead corresponding to 2% of body burden of CPb, i.e. 0.23 mg and 0.35 mg, was converted from NPb to CPb during the 24 h after CaEDTA injection in the two lead workers with blood lead concentrations of 44 μg per 100 g and 61 μg per 100 g, respectively. A previous model for estimating body burden of CPb from mobilization yield of lead by CaEDTA was amended in the light of this estimation.
Investigation of the interaction between Probon® and indomethacin in rats
Authors: Sebestyén Gyula , Gergely Vera , Virág Sándor , Mészáros Zoltán
Published: October 2006

The toxic side‐effects and anti‐inflammatory activity of combination treatment of Sprague‐Dawley rats with indomethacin and Probon, a new type of analgesic, were investigated. Following four weeks of treatment with a combination of these two drugs, the characteristic gastrointestinal side‐effect of indomethacin was markedly reduced. Mortality resulting from administration of the drug combination was significantly lower than that resulting from indomethacin treatment alone. The reduced toxicity of indomethacin in combination with Probon is probably due to a change in metabolism produced by the hepatic microsomal enzyme inducer, Probon. The anti‐inflammatory effect was also investigated using a contact thermographic method following one, three or seven days pretreatment. The advantage of this combination is that, using a higher dose of indomethacin in combination with the minor analgesic, we could achieve a more reliable anti‐inflammatory effect together with a pain‐killing action.
Hormonal changes and adenylate cyclase system in rats bearing 7800 Morris Hepatoma
Authors: Mourelle Marisabel
Published: October 2006

Adenylate cyclase activity was measured in plasma membranes isolated from Morris Hepatoma 7800 and from control and host livers. The only difference found in tumor enzyme activity was the lack of response to glucagon. The membrane‐binding capacities for the pancreatic hormones insulin and glucagon were measured. Hepatoma membranes did not bind glucagon. Insulin‐binding parameters could not be determined because of high non‐specific binding. The plasma levels of insulin in the tumor‐bearing animals were approximately half of those found in controls, whereas the glucagon levels in plasma were 50% higher in tumor‐bearing animals. Thyroxine and triiodothyronine plasma levels were reduced in tumor‐bearing rats, while the thyroid‐stimulating hormone level was within normal limits. The amount of cAMP (275 pmol g−1) and cGMP (3.6 pmol g−1) in the tumor were lower than in the host and control livers, but the ratio of cGMP to cAMP in the tumor was increased by a factor of 2. These results are discussed with respect to control mechanisms of cell proliferation in comparison with other hepato‐proliferative states.
Fibrogenic potential of welding fumes
Authors: Stern R. M. , Pigott G. H. , Abraham J. L.
Published: October 2006

A search of 3600 indexed pathology cases has disclosed pulmonary fibrosis in 29 welders. Scanning electron microscopy of biopsy material revealed macrophages laden with inorganic particulates which have characteristics compatible with welding aerosols. In order to establish a possible relationship between fibrotic reaction and welding‐fume exposure, the fibrogenic potential of some 11 different welding fumes and metallic aerosols, considered to be reference standard surrogates for the commonly used welding technologies and applications responsible for 70% of welders exposure, were screened using the Rat Peritoneal Macrophage in vitro bioassay. Only one class of fumes, that from the manual metal arc welding of stainless steel, showed distinct fibrogenic potential. This fume is, however, not common to more than four or five of the heretofore 90 cases of pulmonary fibrosis reported among welders. Thus, although insoluble Cr(VI) is probably the active fibrogen in stainless steel fumes, an etiological factor common to all fibrogenic welding exposures must be sought. It is tentatively proposed to be NO2, a potent experimental in vivo fibrogen copiously produced by certain welding processes and ubiquitous at low concentrations in the welding environment.
A generalized extraction‐TLC procedure for indentification of drugs
Authors: Warfield Robert W. , Maickel Roger P.
Published: October 2006

A combination of liquid—liquid extraction and thin‐layer chromatography permits rapid identification of a large variety of drugs in pharmaceutical or street dosage forms, or in biological materials. The system utilizes selective pH extraction combined with internal standards. Limits of sensitivity are in the sub‐microgram level. The procedure is rapid and requires minimal equipment and training of personnel. It can be applied to situations in toxicology involving both clinical and forensic demands.
Detectability in vivo of stabilized intercalating agents with the alkaline elution technique comparison with in vivo sister chromatid exchange induction
Authors: Russo Patrizia , Pala Mauro , Ottaggio Laura , Vecchio Daniela , Santi Leonardo , Parodi Silvio
Published: October 2006

The purpose of the work reported here was to investigate, with the alkaline elution technique, the capability of in vivo administered actinomycin D, daunomycin and mitomycin C to induce DNA damage, DNA interstrand cross‐linking and DNA‐protein cross‐linking. The ability of these compounds to induce increases in sister chromatid exchange (SCE) in the bone marrow cells of mice was also investigated. Actinomycin D and daunomycin were active in inducing single strands breaks, while mitomycin C was inactive. Mitomycin C showed a clear DNA interstrand cross‐linking activity, while this activity was absent in actinomycin D and daunomycin. All three compounds were positive for SCE induction, but mitomycin C was by far the most active compound. Our results seem to suggest that stabilized intercalating agents are often detectable with the alkaline elution technique, after treatment in vivo. However, they cannot be evaluated with the simple alkaline elution technique only. It is convenient to add to the basic method the modification for detecting cross‐links. Finally, DNA interstrand cross‐linking and sister chromatid exchanges could be correlated.
The experimental administration of lead to rats in neuropathological and behavioural studies
Authors: Winder Christopher , Carmichael Neil G.
Published: October 2006

The experimental investigation of the effects of lead have been studied for nearly 20 years. In that time, a variety of neurobiological processes have been reported to be altered following ingestion of lead. Most routes of administration and a bewildering number of doses have been employed to administer lead to experimental animals. However, inadequate characterization of dose regimes has impaired understanding of any effects, and their correlation to conditions of human exposure. As an index of lead burden, blood lead remains the most reliable means of assessing recent lead absorption. It is clear that a large number of model systems and dosing regimes do not address the problems of human clinical or subclinical lead intoxication. It is also clear from brain lead measurements in experimental animals that lead is selectively sequestered into specific areas of the control nervous system.
Methylmercury poisoning in Iraq. An epidemiological study of the 1971—1972 outbreak
Authors: Greenwood Michael R.
Published: October 2006

Following the Iraq methylmercury poisoning epidemic in 1971–72, surveys were conducted on selected rural populations to determine the extent of exposure to methylmercury. It was calculated that 40% of those receiving treated grain will have consumed it. Study of death registries in three provincial capitals and their Qada centers reveals that, in the year November 1971 to October 1972, more deaths occurred than in the corresponding period of other years. These deaths were in addition to the 459 deaths which occurred in hospitals. Deaths for the 1–10 and 11–20 year age groups during the year 1971–72 were four‐fold higher than the mean of the two preceding and two following years. However, when adjusted for the age distribution of the population, no one age group had a statistically significant higher incidence of poisoning. Registered live births decreased in 1973, the year following the epidemic, but, at the present time, there is not sufficient information to know the significance of this decrease.
The effect of handling techniques on serum alt activity in mice
Authors: Swaim L. D. , Taylor H. W. , Jersey G. C.
Published: October 2006

The effect of handling mice by the tail or by the body on serum alanine transaminase (ALT) activity was investigated in normal mice and in mice pretreated with a known hepatotoxin. In normal mice, the mean ALT activity 1 h after grasping the body was almost four times greater than in the control (not‐handled) and tail‐handled groups. However, when ALT analyses were repeated 1 week later, all groups were equivalent. In mice given a hepatotoxic dose of 30 mg kg−1 carbon tetrachioride, the mean ALT activity was approximately three times greater in mice handled by the body than in mice grasped by the tail only. Handling mice by the body may reduce the usefulness of ALT activity as a measure of hepatotoxicity.
Dermal absorption of pesticides calculated by deconvolution
Authors: Fisher Henry L. , Most Bernard , Hall Larry L.
Published: October 2006

Using published human data on skin‐to‐urine and blood‐to‐urine transfer of 12 pesticides and herbicides, the skin‐to‐blood transfer rates for each compound were estimated by two numerical deconvolution techniques. Regular constrained deconvolution produced an estimated upper limit on cumulative dermal absorption of the radiolabel, while minimized deconvolution produced an upper bound on cumulative dermal absorption of parent compound. Dermal absorption rate was largest within 8 h of dosing for all pesticides examined. Only carbaryl showed a lag (3.5 h) in penetration. This may indicate a prolonged transit time through skin or a chemical transformation in skin has occurred. After onset, absorption occurred rapidly with 45% of the 120 h cumulative absorption occurring in 8 h. For parathion and dieldrin, over 50% of the 120 h total absorption occurred in the first 4 h. The deconvolution technique described here permits the calculation of the temporal aspect of dermal absorption for linear systems.
The effect of alcide®, a new antimicrobial drug, on rat blood glutathione and erythrocyte osmotic fragility, in vitro
Authors: Abdel‐Rahman Mohamed S. , Scatina Joann
Published: October 2006

Alcide† is an antimicrobial drug which has been demonstrated to kill a variety of common pathogenic bacteria as well as fungi, in vitro. This agent is supplied in liquid and gel forms and consists of two parts, one of which contains sodium chlorite, while the other contains lactic acid as the active ingredients. Mixing of the two parts prior to use produces chlorine dioxide (ClO2), a strong oxidizing agent. A dose‐dependent decrease in glutathione content and erythrocyte osmotic fragility occurred after incubation of whole blood with alcide®. Glutathione concentration and erythrocyte osmotic fragility approached the control values after 240 min of incubation with alcide® containing 1 mM NaClO2. The addition of exogenous glutathione (50 mg 100 ml−1) or glutathione reductase and NADPH to rat blood in the presence of alcide® returned erythrocyte osmotic fragility to control values. Treatment of rat blood with alcide® did not change glutathione reductase or glutathione peroxidase activities after 1 h of incubation.
Stability of aroclor 1254–induced rat liver postmitochondrial supernatant (s‐9) following long‐term storage (−75°c)
Authors: Oldham James W. , Pritchard J. Frederick , Preston Robert F. , Nomides Charles T. , Patton Wanda E. , Paulson John D.
Published: October 2006

The stability of Aroclor 1254‐induced rat liver postmitochondrial supernatant (S‐9) over a 5‐year period was investigated in a retrospective study. S‐9 was uniformly prepared at 6‐month intervals, and aliquots were stored at −75°C. The protein and cytochrome P‐450 content of these lots of S‐9 were very similar, and no differences attributable to duration of storage were observed in the activities of ethoxycoumarin O‐deethylase, aniline hydroxyiase, cytochrome P‐450 reductase or aryl hydrocarbon hydroxylase. There was no decrease following 5 years of storage in the ability of S‐9 to activate 2‐aminoanthracene, as measured in the Ames test (TA98), but there was a notable reduction following more than 1 year of storage in the ability of the S‐9 to generate Ames test activity with benzo(a)pyrene. Based on the results of these studies, S‐9 prepared and stored under these conditions appears to be suitable for use in in vitro genotoxicity assays for at least 1 year.
A comparison of the acute toxicity of chemicals to fish, rats and mice
Authors: Hodson Peter V.
Published: October 2006

The acute toxicity of chemicals to rainbow trout, as shown by intraperitoneal injections (IP LD50), oral dosing (oral LD50) and aqueous exposure (LC50) was compared with published values for IP LD50s and oral LD50s of mice and rats. The method of comparison was by simple linear regression analyses of log‐transformed data, modified to recognize that X (fish toxicity) was neither fixed nor measured without error.

Within‐species comparisons demonstrated very strong linear correlations (r =0.866–0.998) between IP and oral LD50s. Variability was least for the fish data since it was all generated in one laboratory.

Comparisons between species of IP and oral LD50S gave correlation coefficients ranging from 0.59 to 0.95 with the majority over 0.80. Correlations were best (r =0.83–0.94) between fish LD50s and rat and mice IP LD50s. Correlations were poorest between fish and mammalian oral LD50s (r =0.59–0.66) because the sample sizes and the ranges of values were very small. In all cases, the slopes were close to, or equalled, 1.0.

Comparisons of fish LC50s to fish or mammalian LD50s were not as successful. Correlation coefficients ranged from 0.19 to 0.83. Presumably the cause was the aqueous exposure. Interactions of the chemicals with water (e.g. dissociation) and with lipid membranes (partitioning) should cause considerable variations in uptake efficiency. However, adjustments of LC50s for dissociation constants and partition coefficients did not improve these correlations, probably because there were few chemicals for which all data were available.

These comparisons demonstrate a potential for a wider use of surrogate species in toxicity testing and for adapting existing data from mammalian toxicology to aquatic hazard assessments.
Detection of teratogenic substances in acidic mine water samples using the frog embryo teratogenesis assay — Xenopus (FETAX)
Authors: Dawson Douglas A. , McCormick Curt A. , Bantle John A.
Published: October 2006

The FETAX (Frog Embryo Teratogenesis Assay — Xenopus) whole embryo bioassay has been developed to screen for environmental substances that cause birth defects. We have used this assay to test its effectiveness in working with actual water samples from the field. Tar Creek is contaminated by discharges from abandoned lead and zinc mines. In addition to high concentrations of zinc, iron and other metals, water samples are routinely low in pH and oxygen content. The pH values of three Tar Creek sample sites were below the established tolerance limits of the embryos. Therefore, one group of samples had no pH adjustment while a second group had the pH adjusted to 7.0. Two of the four sites contained agents that reduced embryonic growth and caused high rates of mortality. A third site contained teratogenic substances. We have determined that metal content is responsible, along with the low pH, for the biologic effects. We have identified high concentrations of toxic metals in Tar Creek by water analysis and were able to demonstrate, by removing metals via Chelex® 100 ion exchange chromatography, that the observed toxicity and teratogenicity were caused by metal ions.

We have concluded that FETAX is an excellent test for complex mixtures. Physicochemical parameters, such as pH, oxygen and metals content, can be altered and the effect of these changes on toxicity and teratogenicity determined using FETAX. The interaction of toxic substances and low pH are important when considering embryo survival and development.
Potential uses of sea urchin embryos for identifying toxic chemicals: Description of a bioassay incorporating cytologic, cytogenetic and embryologic endpoints
Authors: Hose Jo Ellen
Published: October 2006

A method for evaluating pollutant genotoxicity, embryotoxicity and teratogenicity using sea urchin embryos has been developed and was tested using benzo (α) pyrene (BP). Initial results suggested that the bioassay may be a sensitive indicator of pollutant toxicity and mutagenicity since several endpoints can be simultaneously assessed. The bioassay is rapid, inexpensive and appears applicable to a variety of toxicants and delivery methods. The test is based upon the standard 48 h sea urchin development assay and incorporates cytologic–cytogenetic analysis of embryos. Following toxic exposure of gametes, fertilization success is assessed. Embryos then develop for 48 h at which time survival and teratogenesis are evaluated. A subsample of embryos is stained and dissociated into monolayers and mitotic configurations are examined using light microscopy. Embryo mitotic rates are used as an indicator of overall embryonic health. Cytotoxic effects are concomitantly evaluated. Genotoxicity is measured using two methods: (1) anaphase aberration analysis, a technique which assesses abnormalities in the chromosome configurations (such as bridges and fragments) as the groups of chromosomes move to opposite poles and (2) micronucleus formation, a procedure examining the incidence of smaller, secondary nuclei composed of whole chromosomes or chromatid fragments. These two measurements preclude the need to examine individual chromosomes for deletions and exchanges, a laborious process in most aquatic organisms which possess numerous relatively small chromosomes.

This genotoxicity–teratogenicity test appears promising for laboratory evaluations of individual substances or of complex chemical mixtures as weii as for environmental monitoring of nearshore areas. The standard development assay has been used to screen pharmaceuticals and environmental contaminants and some recent investigations have included mitotic aberration analysis. Experiments in our laboratory suggest that the genotoxicity–teratogenicity test may be a feasible approach to field monitoring. Mutagen loads of spawning adult urchins could be assessed by conducting cytologic–cytogenetic analysis of resulting embryos although initial studies suggest that this method is less sensitive than direct embryo exposures.
Similar profile of urinary and faecal metabolites of 14C‐carmoisine in male and pregnant female rats after oral administration
Authors: Tragni E. , Flaminio L. M. , Galli Corrado L. , Marinovich M.
Published: October 2006

Pregnant rats received 14C‐Carmoisine (200 mg kg−1; 25 μCi) by gavage on days 16–19 of gestation. The animals were killed and maternal tissues, amniotic fluid, placentae, foetal membranes and foetuses were analyzed for radioactivity. No evidence for the transplacental transfer of 14C‐Carmoisine or its metabolites was obtained. Male rats were given a single oral administration of 14C‐Carmoisine (200 mg kg−1; 25 μCi) and killed at different times after dosing. In both male and female animals, more than 90% of the radioactivity was excreted in faces and urine within 64 h, and the results suggested that there was no significant absorption of the azodye and no preferential concentration of the red food colour or its metabolites in any particular tissue. Analyses by HPLC, combined with a radioactivity monitor (RAM), of urine and faces of such animals show that five radioactive peaks were present in the radiochromatogram in addition to unmodified Carmoisine. The mean peak shows the retention time and the u.v. spectrum of authentic naphthionic acid. The results demonstrate that the pregnancy does not affect the kinetic and the metabolic profile of a single oral administration of the azodye Carmoisine given at different days of gestation.
A comparison of two bioassays used to estimate the toxicity of lupin material infected with Phomopsis leptostromiformis
Authors: Allen J. G. , Petterson D. S. , Ellis Z.
Published: October 2006

Eighty‐four lupin samples were tested for toxicity using two currently available bioassays. One utilizes sheep and the other nursling rats. There was an association between the results obtained by the two bioassays but 65% of the variance of the nursling rat bioassay results was not associated with the sheep bioassay results in the linear regression. Reasons for this poor correlation are suggested and discussed.
Pulmonary function responses in cats following long‐term exposure to diesel exhaust
Authors: Moorman William J. , Clark John C. , Pepelko William E. , Mattox Joan
Published: October 2006

Long‐term inhalation studies were carried out to evaluate the toxic pulmonary effects of diesel engine emissions. Cats were exposed for over 2 years to whole, diluted diesel exhaust at levels expected to produce frank toxic effects. During the first 61 weeks of exposure, the cats received exhaust having a particulate level of 6 mg m−3. This was followed by a doubling of the exposure level from weeks 62 to 124 resulting in particulate levels of 12 mg m−3. No definitive pattern of pulmonary function response was observed following 61 weeks; however, a classic pattern of restrictive lung disease was found at 124 weeks. The significantly reduced lung volumes and diffusing capacity were indicative of a pulmonary interstitial response which was later verified by histopathology.