Tumor induction with hexanal methylformylhydrazone of Gyromitra esculenta

Hexanal methylformylhydrazone (HMFH) was administered to Swiss mice by intragastric instillations at weekly intervals of 52 times at 50 or 100 /g body weight. The treatment induced tumors of the lungs, liver and preputial glands. The tumor incidences in the group that received the lower dose were 74, 4 and 0% in females and 78, 8 and 6% in the males. In the group with the higher dose, the incidences were 90, 28 and 0% in females and 70, 6 and 86% in males. The corresponding tumor incidences in the untreated animals were 26, 0 and 0% in females and 26, 0 and 0% in males. The histopathological examination revealed adenomas and adenocarcinomas of lungs, benign hepatomas and liver cell carcinomas and squamous cell papillomas and carcinomas and adenomas of preputial glands. HMFH is the sixth carcinogenic ingredient found in one of the false morel mushrooms, Gyromitra esculenta. Because this fungus is considered edible, the health hazard implications cannot be discounted.     

Carcinogenesis by pentanal methylformylhydrazone of Gyromitra esculenta in mice

Pentanal methylformylhydrazone (PMFH) given in propylene glycol as 52 weekly intragastric instillations on a 50 g/g body weight basis, induced tumors of the lungs, liver and preputial glands in Swiss mice. The tumor incidences in these tissues were 72, 16 and 0% in the treated females, while these tumor incidences in the males of this group were 60, 2 and 12%, respectively. The corresponding tumor incidences in the propylene glycol instilled solvent control females were 26, 0 and 0%, whereas in the males of this group they were 22, 0 and 0%, respectively. Histopathologically, the tumors were classified as adenomas and adenocarcinomas of the lungs, benign hepatomas and squamous cell papillomas and carcinomas of the preputial glands. Pentanal methylformylhydrazone is an ingredient of the edible wild mushroom Gyromitra esculenta which is consumed by a segment of the human population around the world.     

Spontaneous tumors in aged SD-JCL rats (author's transl)

Incidence of spontaneous tumors was examined in 77 male and 73 female SD-JCL rats reared throughout their lifespan of 5 to 36 months. Total tumor incidences were 60% and 95% for males and females, respectively. The sex difference was mostly attributable to a high incidence of mammary tumor in females. The pituitary tumor was found in 30% of males and 66% of females aged 5 to 36 months while islet cell tumor of the pancreas and thyroid tumor occurred later and the incidence of latter was particularly high in rats lived more than 2 years. Myeloid leukemia appeared to occur as early as 5 months of age.     

Spontaneous neoplastic lesions in aged Sprague-Dawley rats.

Neoplastic lesions were observed in untreated aged Sprague Dawley (SD) rats throughout their lifespan starting at 5 weeks. Their mean survival times were 89 to 105 weeks of age. The total tumor incidences were 70 to 76.7% and 87 to 95.8% in males and females, respectively. The common neoplasmas were pituitary adenoma and adrenal pheochromocytoma in both sexes, testicular Leydig cell tumor in males and mammary gland tumors, thyroidal C-cell adenoma and uterine stromal polyp in females.     

Life span and spontaneous tumors incidence of the Wistar Mishima (WM/MsNrs) rat.

The life spans and spontaneous tumors in a total of 1960 Wistar Mishima (WM/MsNrs) rats, inbred strain, from the 80-130th generations were examined. The average life span (mean +/- SD) was 731 +/- 173 days (n = 1053) in the males and 813 +/- 214 days (n = 907) in the females (p < 0.0001). The average life span of tumor-afflicted females was significantly longer than that of the non-tumor group (p < 0.0001), while no such difference was observed in males. Tumors were observed in 33 males (3.1%) and 246 females (27.1%). In the males, tumors were often observed under the skin (2.2%). Frequencies of tumors in lung and liver, bones and intestine were less than 0.5%. In the females, incidence of mammary tumor was 20.1%, and various organs such as ovaries, uterus, bones, lung, and liver had tumor incidence frequencies of less than 3.5%. It was concluded that WM/MsNrs rats might be suitable for life span and age-related studies because of their characteristics of length of longevity and the low incidence of spontaneous tumors in both sexes.     

On critical night lengths and temperature compensation in the photoperiodic response of two geographical clones of the black bean aphid, Aphis fabae

Photoperiodic response curves were determined for two clones of the black bean aphid, Aphis fabae Scopoli, at three temperatures, 12.5, 15 and 17.5°C. Critical night lengths for the induction of winged females in an English clone (52° N) were 10.5, 11 and 11.5 h, respectively, and 10, 10.5 and 11 h in a Scottish clone (57° N). Critical night lengths for male induction were 10.5, 11 and 11 h at 12.5, 15 and 17.5°C in the English clone, and 10, 10.5 and 10.5 h, respectively, in the Scottish clone. High incidences of winged females and males were observed at all scotophases longer than the critical night length in both clones. In addition, in the English clone, the incidences of winged female and male producers in continuous darkness were 0% at 15 and 17.5°C, and 6% at 12.5°C. In the Scottish clone, however, continuous darkness resulted in high incidences of both winged female and male producers at 12.5 and 15°C, but 0% winged female producers and 6% male producers at 17.5°C. In scotophases shorter than the critical night length, including continuous light, no males or winged females were observed in either clone under the non‐crowded rearing conditions used. The results are discussed in terms of the ‘double circadian oscillator model’ for photoperiodic induction.     

The age-related tumor incidence in Wistar-Imamichi rat

The age-related incidences and types of spontaneous tumors were studied in 320 male and 354 female Wistar-Imamichi rats reared up to 130 weeks of age. The tumor incidence increased abruptly between 53 and 78 weeks of age, and 170 males and 269 females were shown to bear tumors during the observation period. Multiple tumors occurred in 62 males and 115 females. Most common were hypophyseal (male 69: female 224), mammary gland (29:99), testicular (74:0) and adrenal gland (26:21) tumors. The incidences of hypophyseal and testicular tumors increased with age. Tumors occurred in later stages of the observation period in the ovary, uterus and vagina (0:27), thyroid and parathyroid (13:12), skin (8:8), spleen and lymph nodes (8:7), pancreas (9:5), liver (3:7), lung (3:3), thymus (1:4), omentum and mesenterium (2:3), stomach and intestine (2:2), kidney and urinary bladder (1:2), right femur (0:1), and brain (0:1).     

Calculation of the 1995 lung cancer incidence in the Netherlands and Sweden caused by smoking and radon: risk implications for radon

A two-mutation carcinogenesis model was used to calculate the expected lung cancer incidence caused by both smoking and exposure to radon in two populations, i.e. those of the Netherlands and Sweden. The model parameters were taken from a previous analysis of lung cancer in smokers and uranium miners and the model was applied to the two populations taking into account the smoking habits and exposure to radon. For both countries, the smoking histories and indoor radon exposure data for the period 1910-1995 were reconstructed and used in the calculations. Compared with the number of lung cancer cases observed in 1995 among both males and females in the two countries, the calculations show that between 72% and 94% of the registered lung cancer cases may be attributable to the combined effects of radon and smoking. In the Netherlands, a portion of about 4% and in Sweden, a portion of about 20% of the lung cancer cases (at ages 0-80 years) may be attributable to radon exposure, the numbers for males being slightly lower than for females. In the Netherlands, the proportions of lung cancers attributable to smoking are 91% for males and 71% for females; in Sweden, the figures are 70% and 56%, respectively. The risk from radon exposure is dependent on gender and cigarette smoking: the excess absolute risk for continuous exposure to 100 Bq m-3 ranges between 0.003 and 0.006 and compares well with current estimates, e.g. 0.0043 of the International Commission on Radiological Protection (ICRP). The excess relative risk for continuous exposure to 100 Bq m-3 shows a larger variation, ranging generally between 0.1 for smokers and 1.0 for non-smokers. The results support the assumption that exposure to (indoor) radon, even at a level as low as background radiation, causes lung cancer proportional to the dose and is consistent with risk factors derived from the miners data.     

Acarbose improves health and lifespan in aging HET3 mice

To follow‐up on our previous report that acarbose (ACA), a drug that blocks postprandial glucose spikes, increases mouse lifespan, we studied ACA at three doses: 400, 1,000 (the original dose), and 2,500 ppm, using genetically heterogeneous mice at three sites. Each dose led to a significant change (by log‐rank test) in both sexes, with larger effects in males, consistent with the original report. There were no significant differences among the three doses. The two higher doses produced 16% or 17% increases in median longevity of males, but only 4% or 5% increases in females. Age at the 90th percentile was increased significantly (8%–11%) in males at each dose, but was significantly increased (3%) in females only at 1,000 ppm. The sex effect on longevity is not explained simply by weight or fat mass, which were reduced by ACA more in females than in males. ACA at 1,000 ppm reduced lung tumors in males, diminished liver degeneration in both sexes and glomerulosclerosis in females, reduced blood glucose responses to refeeding in males, and improved rotarod performance in aging females, but not males. Three other interventions were also tested: ursolic acid, 2‐(2‐hydroxyphenyl) benzothiazole (HBX), and INT‐767; none of these affected lifespan at the doses tested. The acarbose results confirm and extend our original report, prompt further attention to the effects of transient periods of high blood glucose on aging and the diseases of aging, including cancer, and should motivate studies of acarbose and other glucose‐control drugs in humans.     

Association between polymorphisms of VKORC1 and CYP2C9 genes with warfarin maintenance dose in a group of warfarin users in Birjand city,Iran

Warfarin is the cardinal anticoagulant drug prescribed around the world. Due to stochastic bleeding in patients, it is essential to adjust the dose for every individual. The aim of the present study was to evaluate the frequency of CYP2C9 and VKORC1 gene polymorphisms and their association with warfarin maintenance dose in a sample of cardiovascular patients in Birjand, South-Khorasan province of Iran. Patients with a history of cardiovascular disorders who take warfarin daily were selected. CYP2C9 and VKORC1 gene polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism in all participants. A total of 114 patients (mean age: 52.7 ± 14.9 years, M/F ratio: 0.76) participated in this study. Regarding CYP2C9 gene polymorphisms, the most frequent genotype was 1*/1* (80.4% in females and 62.5% in males). The frequency of 1*/2* and 2*/2* variants was 13% and 6.5% in females and 25% and 12.5% in males, respectively. The frequency of VKORC1 gene (1639 G > A), was 31.5%, 39.5%, and 29% for GG, GA, and AA in males, respectively. Besides, the mentioned genotype frequencies for females were 50%, 40.5%, and 9.5%, respectively. Moreover, there was a statistically significant correlation between VKORC1 gene −1639 G > A variant and warfarin maintenance dose (P < 0.001) but not for CYP2C9 variants. The results of the current study confirmed that the mutant variants of CYP2C9 are not frequent and do not have any impact on warfarin dose. In the case of VKORC1, the mutant allele (A) showed a positive correlation with warfarin dose adjustment.     

Dosage compensation of sex-linked genes in Drosophila melanogaster. The activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase in flies with normal and disturbed genetic balance

Summary The phenomenon of dosage compensation in Drosophila melanogaster which consists in doubling of the activity of the X-chromosome genes in males as compared to those in females was studied.The specific activities of 6-phosphogluconate dehydrogenase (6PGD) and glucose-6-phosphate dehydrogenase (G6PD) determined by the sex-linked structural genes Pgd and Zw respectively were studied in flies carrying duplications for different regions of the X-chromosome. The increase in dose of Pgd and Zw in females resulting from the addition of an extra X-chromosome or X-fragments leads to a proportional rise in the specific activities of 6PGD and G6PD. On the other had the addition to females of the X-chromosome carrying no Pgd gene or X-fragments lacking Pgd and Zw has no effect on the enzyme activities. Thus we failed to reveal in the X-chromosome any compensatory genes envisaged by Muller, which would repress sex-linked structural genes proportional to their dose.The 6PGD and G6PD levels in phenotypically male-like intersexes carrying two X-chromosomes and three autosome sets (2X3A) is 30% higher than in diploid (2X2A) or triploid (3X3A) females. However the specific activities of the enzymes in female-like intersexes are the same as in regular females. The levels of 6PGD and G6PD per one X-chromosome are 1.5–2.0 times higher in the intersexes than in the normal females and metafemales (3X2A). The results indicate that the level of expression of the X-chromosome is determined by the X:A ratio. It is suggested that the decreased X:A ratio in males is responsible for the hyperactivation of their X-chromosomes.     

Attractiveness and competitiveness of irradiated light brown apple moths

The sterile insect technique (SIT) potentially provides a socially acceptable approach for insect eradication of new pest incursions. The light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), was discovered in Berkeley (CA, USA) in 2006, leading to an incursion response that included this technology. In this study, we assessed factors affecting mating success from a bisex release of irradiated moths: effects of radiation dose on male multiple mating, male flight competition, female sex pheromone titre and attractiveness of irradiated females to males, and identification of successful mating in vineyards of either irradiated or wild males (identified by isotope analysis of spermatophores from sentinel females). There was a significant negative relationship between male radiation dose and mating frequency. In head‐to‐head flights of irradiated males against non‐irradiated males to a pheromone lure in a wind tunnel, irradiated males reached the lure first only 31% of the time. With increasing radiation dose, the production of the major sex pheromone component in females, (E)‐11‐tetradecenyl acetate, dropped, from 0.7 ± 0.1 ng per female in non‐irradiated females to 0.2 ± 0.07 ng per female when irradiated at 300 Gy. Male catch was reduced to 11% of control females in traps containing females irradiated at 300 Gy. Isotope analysis of spermatophores found in the bursa copulatrix of females indicated that mating success of irradiated males inside the live (entry‐only) traps containing virgin females was lower (13.1 ± 3.3%) than suggested by male catch (21.2 ± 3.8%) in pheromone traps, the current standard for assessing field competitiveness. Impacts of irradiation on male and female moth fitness should be taken into account to improve estimates of irradiated to wild male E. postvittana overflooding ratios needed for population suppression.     

Effects of gamma radiation on spermatophore production and reception and subsequent fecundity and egg viability inAcarus siro L. (Acari: Acaridae)

Gamma radiation at doses higher than 10 krad significantly lowered the fecundity of the grain mite,Acarus siro. The fecundity of irradiated females was inversely correlated with dose, both when control or irradiated males were used in the pairing.Irradiation with ionizing radiation affected sexual activity of males. At doses above 10 krad the number of formed or observed spermatophores was lowered significantly.Sexual attractiveness of irradiated and control females to irradiated males was similar. However, non-irradiated males were observed mating more often with non-irradiated than with irradiated females.No correlation was found between the numbers of spermatophores present in the spermathecae of the female and the fecundity of the female. Irradiation had a greater effect on fecundity of the female than on sexual activity of the male; it did not affect the shape or behavior of spermatophores in the spermathecae of the female.Viability of eggs laid by females decreased by at least 50% when females or males were irradiated with doses above 20 krad. Irradiation also affected the survival of adults, but females were more sensitive than males. Net sterility index indicates that doses higher than 20 krad induce more than 90% sterility.     

Influence of age and sex on hepatotoxic and hypothermic effects of estrogole in mice

Some physiological effects of estragole under a single intraperitoneal injection in oil solution were studied in GR mice; elevation of blood aminotransferases activity, body temperature and animals lethality were registered. At a dose of 600 mg/kg, estragole killed 100% sucklings of both sexes and 90% adult females but no any adult male. The males aquire resistance to estragole at the time of maturation. Exogenous testosterone administered at the dose of 50 mg/kg 4-2 days earlier increases the resistance of female mice to estragole up to its level in males. However, neonatally androgenized females are as sensitive to the toxic action of estragole as the males. At the dose of 900 mg/kg, estragole defeats adult males as well: significant elevation of aminotransferase activities in their blood is indicative of this. In this case, the enzyme activity reaches its peak after 2-3 days, not at the 1st day as in the case of carbon tetrachloride administration. We have discovered a strong hypothermic effect of estragole which appears to be unrelated to its hepatotoxicity and testosteron level.     

A reanalysis of liver cancer incidence in Danish patients administered thorotrast using a two-mutation carcinogenesis model

In recent years, a two-mutation carcinogenesis (TMC) model has been used to analyze epidemiological data and estimate the radiation risks at low doses for the organs affected. Here the TMC model was used to reanalyze the liver cancer incidence in the Danish population in general and in patients administered Thorotrast, and to estimate the radiation risks for the liver. The data for 807 patients for whom sufficient data on the injected volumes of Thorotrast were available were used in this reanalysis. These data were combined with data on liver cancer incidence in the Danish population as the baseline or background incidence. Because males and females show different baseline liver cancer incidences, separate fits were made for males and females. The fits showed that the radiation effect could be ascribed entirely to the radiation dependence of the first mutation rate of the TMC model, which was higher for females than for males. The second mutation rate was not significantly dependent on dose. The radiation risks for the liver were calculated on the basis of the model parameters. These risks for lifetime exposures are about the same for males and females and are between a factor of 2 and 10 higher than current estimates. The discrepancy between the model results and previous risk estimates probably arises because the model calculations give more complete lifetime radiation risk estimates. For short-term exposures of the liver to ionizing radiation, the maximum radiation-induced excess liver cancer risk per unit dose applies to exposures at the age of about 10; exposures at ages above 35 have a radiation effect of less than approximately 15% of this maximum.     

Genetic analysis for insulitis in NOD mice

Non-obese diabetic (NOD) mice spontaneously develop diabetic signs akin to those of Type I diabetes in man. Insulitis, i.e., lymphocytic infiltration around and into the pancreatic islets is one of the characteristics of such mice. It is also the etiologic pathological lesion in the development of diabetes mellitus in NOD mice. Thus, we chose insulitis as a marker for genetic analysis of the development of diabetes mellitus in NOD mice and clarified the mode of its inheritance. In breeding studies between NOD and C57BL/6J mice, insulitis was not observed in the F1 and (F1 X C57BL/6J) backcross generations, but was found with incidences of 3.9% in females and 1.4% in males in the F2 generation and 23.7% in females and 12.1% in males in the (F1 X NOD) backcross generation. These incidences in the F2 and (F1 X NOD) backcross females corresponded approximately to 1/16 and 1/4 of the incidences of 89.7% in the NOD females, respectively. A similar relationship was observed between the F2 and (F1 X NOD) backcross males and the NOD males. When the gene expressivity of both sexes for a double recessive homozygote was assumed to be the incidences of insulitis in 9-week-old NOD females and males, respectively, the expected numbers of both sexes with and without insulitis in the F2 and backcross generations agreed well with the observed ones. These observations suggest that two recessive genes on independent autosomal chromosomes are necessary for the development of insulitis in NOD mice.     

Evaluation of partial sterility in mating performance and reproduction of the West Indian sweetpotato weevil,Euscepes postfasciatus

The sterile insect technique (SIT) is based on population and behavioral ecology and is widely used to suppress or eradicate target pest insect populations. The effectiveness of SIT depends on the ability of the released sterile males to mate with and inseminate wild females. The use of gamma‐radiation to induce sterility is, however, associated with negative impacts not only on reproductive cells but also on somatic cells. Consequently, irradiation for sterilization diminishes mating performance over time. In this study, we evaluated the balance between the irradiation dose and both fertility and mating propensity in Euscepes postfasciatus (Fairmaire) (Coleoptera: Curculionidae) for 22 days following irradiation. The mating propensity of males irradiated with a 150‐Gy dose, as currently used to induce complete sterility of E. postfasciatus in the SIT program in Okinawa Prefecture, was equal to that of non‐irradiated weevils for up to 6 days, and the mating propensity of males irradiated with a dose of 125 Gy was equal to that of non‐irradiated weevils for twice this period (12 days). The fertilization ability of weevils irradiated with a dose of 125 Gy was reduced by 4.6% in males and 0.6% in females, compared to the potential fertilization ability. We also discuss the possibility of the application of partially sterilized insects in eradication programs.     

Reconstruction of Parentage in a Band of Captive Hamadryas Baboons

The male leaders of free-ranging harem groups of hamadryas baboons are believed to mate exclusively with the female members of their harems, which typically contain no more than 2–3 females. Using no-parent parentage exclusion analysis (PEA) we identified the paternity of 25 offspring born in a captive band of hamadryas baboons (Papio hamadryas hamadryas) containing five adult males, each with a stable harem of about five females. Nine of 13 microsatellite (SSR) loci known to be highly polymorphic in rhesus macaques (Macaca mulatta) were successful in identifying the sires of all but two offspring without knowledge of the dams' genotypes, and we were able to determine the sires of all offspring when the dams' genotypes were considered. Mating success of the males ranged between 2 and 7 offspring and bore no clear relationship to the males' ages, ranks or the number of females in their harems. The males sired 7 of the 25 offspring with females outside their own harems, with higher-ranking males exhibiting greater success monopolizing access to females in their harem than lower-ranking males did. More surprisingly, the females assigned as the dams of 14 of the 25 offspring could be unequivocally excluded from parentage. The identity of the true dam could be determined for each of these 14 offspring using single-parent PEA and was uncorrelated with the ranks of these offsprings' sires and whether the offspring were born to dams outside the sires' harem groups. The combined effect of this extraharem mating and kidnapping was that only 12 of the 25 offspring were raised within their sires' harem groups. A second group of hamadryas baboons of identical structure exhibited the same high incidences of infant kidnapping and mating outside the harem group. It is unclear whether these behaviors provide an adaptive advantage or represent aberrant behavior resulting from captivity or other circumstances.     

POSTMATING REPRODUCTIVE ISOLATION BETWEEN CHRYSOPA QUADRIPUNCTATA AND CHRYSOPA SLOSSONAE: MECHANISMS AND GEOGRAPHIC VARIATION

In laboratory tests, Chrysopa quadripunctata showed geographic variation in a postmating, prezygotic barrier to interbreeding with its sister species, C. slossonae. When paired with C. slossonae males, C. quadripunctata females from populations that are sympatric with C. slossonae (i.e. from New York and Florida) had lower incidences of fertile oviposition than those from allopatric populations (i.e. from Kansas and California). Chrysopa quadripunctata females in all interspecific pairings were inseminated, but absence of fertile oviposition was associated with the lack of sperm transfer from the bursa copulatrix to the spermatheca. The C. quadripunctata females that failed to lay fertile eggs when crossed with C. slossonae males, invariably produced viable C. quadripunctata offspring (no hybrids) within one day after the heterospecific male was replaced with a conspecific one. Thus, the barrier to hybridization may involve the ability of females to (a) distinguish between heterospecific and conspecific sperm and (b) allow the transfer of only conspecific sperm to the spermatheca. When C. slossonae females were paired with C. quadripunctata males, the incidences of fertile oviposition were high and there was no apparent geographic variation in the degree of hybridization. As with C. quadripunctata females, unsuccessful hybridization of C. slossonae females was associated with retention of sperm in the bursa copulatrix. Hybrids did not differ from intraspecific offspring in their viability or sex ratios. However, hybrids whose parents originated from sympatric populations had low fertility; thus hybrid infertility may constitute an additional barrier to hybridization. The patterns of inter- and intraspecific variation in hybridization are consistent with the notions that C. quadripunctata harbors variation in the mechanism that controls sperm movement to the spermatheca and that the evolution of reproductive isolation between C. quadripunctata and C. slossonae may include natural selection for increased expression of this mechanism.     

Microscopic dose distribution around PuO2 particles in lungs of hamsters,rats, and dogs

Summary Syrian hamsters, Fischer rats and Beagle dogs inhaled mono-disperse aerosols of PuO₂ and were scarificed during the first 16 days after exposure. The microscopic distribution of radiation dose and tissue-at-risk to alpha irradiation around individual particles in lung was studied using autoradiographs of lung tissue sections. The dose distributions in dogs and rats were more diffuse than in hamsters. A slightly greater tumor incidence was calculated for rats and dogs than for hamsters on the basis of dose distribution using the same dose-effect model for all three species. The small differences in tumor incidence predicted on this basis do not explain the extremely large differences in tumor incidences observed in these species after inhalation of PuO₂.Research performed under U.S. Department of Energy Contract Number DE-AC04-76EV01013. Research conducted in facilities fully accredited by the American Association for the Accreditation of Laboratory Animal Care