Stilbestrol as a factor modifying the toxicity of Ekatin for the Pharaoh quail (Coturnix coturnix Pharaoh). I. Young birds.

1. The noted fall of the erythrocyte count, haemoglobin and haematocrit levels after stilbestrol indicate that this hormone disturbs erythropoiesis, probably by depressing the maturation of erythroid cells in the bone marrow. 2. The reaction of the erythrocyte system of birds intoxicated with Ekatin indicates that this pesticide has a haemolytic influence on the morphotic elements of the blood. 3. Estrogenisation enhances the action of Ekatin on the erythrocyte system by as it seems increasing the susceptibility of the red blood cells to the haemolytic action of this pesticide. 4. The high heterophilic leucocytosis in birds receiving stilbestrol is evidence that this hormone causes by an increased release of corticoids, hyperplasia of the granulopoietic tissue in the bone marrow and depresses the marrow barrier for heterophils. 5. Changes in the leucocyte system of quails intoxicated with Ekatin indicate a stressogenic action of this poison. 6. The reaction of the latter system to Ekatin administered after estrogenisation seems to be an indication that stilbestrol reduces the susceptibility of the quails to the stressogenic action of the pesticide.     

Stilbestrol as a factor modifying the toxicity of ekatin for the pharaoh quail (Coturnix coturnix pharaoh). I. Young birds

1. The noted fall of the erythrocyte count, haemoglobin and haematocrit levels after stilbestrol indicate that this hormone disturbs erythropoiesis, probably by depressing the maturation of erythroid cells in the bone marrow,2. The reaction of the erythrocyte system of birds intoxicated with Ekatin indicates that this pesticide has a haemolytic influence on the morphotic elements of the blood.3. Estrogenisation enhances the action of Ekatin on the erythrocyte system by as it seems increasing the susceptibility of the red blood cells to the haemolytic action of this pesticide.4. The high heterophilic leucocytosis in birds receiving stilbestrol is evidence that this hormone causes by an increased release of corticoids, hyperplasia of the granulopoietic tissue in the bone marrow and depresses the marrow barrier for heterophils.5. Changes in the leucocyte system of quails intoxicated with Ekatin indicate a stressogenic action of this poison.6. The reaction of the latter system to Ekatin administered after estrogenisation seems to be an indication that stilbestrol reduces the susceptibility of the quails to the stressogenic action of the pesticide.     

Stilbestrol as a factor modifying the toxicity of ekatin for the pharaoh quail (Coturnix coturnix pharaoh)—ii. mature birds

1. Stilbestrol significantly modifies the reaction of the erythrocyte system to Ekatin poisoning, increasing the susceptibility of the red blood cells to the haemolytic action of the pesticide.2. This hormone modifies also the reaction of the leucocyte system of birds intoxicated with Ekatin, reducing their susceptibility to the stress-generating action of the pesticide.3. The reaction of mature male quails to poisoning with Ekatin after previous estrogenisation is similar to that of young 3-week-old birds of both sexes.     

Haematological changes in male and female pharaoh quails (coturnix coturnix pharaoh) after ekatin intoxication

• 1.1. The purpose of this study was to determine changes in the blood of pharaoh quails after Ekatin intoxication, to define the duration of disturbances caused by intoxication and to examine possible sex differences in the birds' reaction to intoxication.
• 2.2. It was found that Ekatin reduced the number of erythrocytes, haemoglobin level and haematocrit value, increased erythroblast and reticulocyte numbers and increased the osmotic resistance of blood cells.
• 3.3. It was shown that this pesticide caused neutrophilic leucocytosis with lymphopaenia and eosinopaenia.
• 4.4. In males changes in the blood appeared far earlier than in females and they underwent compensation earlier, that is, 3 weeks after intoxication the majority of the haemotological parameters reached values similar to the control.

     

Effect of a single administration of testosterone on the immune response and lymphoid tissues in mice.

Female mice were given a single intraperitoneal injection of testosterone immediately after irradiation and marrow reconstitution. Thirty days later testosterone had no suppressive effect on the recovery of thymus and spleen weights. Testosterone had no effect on the graft-versus-host reaction. Testosterone had no influence on the survival of the skin homografts. However, the plaque-forming cell response to sheep erythrocytes in the spleen was dramatically suppressed by testosterone. Histological observations revealed marked inhibition of lymphoid regeneration selectively in the thymus-independent areas of the peripheral lymphoid tissues. These results suggest that testosterone would act mainly on the differentiation of stem cells toward the population of bone marrow-derived B lymphocytes. The immune response to sheep erythrocytes was restored completely 90 days after testosterone administration. Testosterone given to normal adult mice can also have suppressive activity on the immune system 30 days after a single intraperitoneal injection.     

睾酮对鸟类繁殖影响研究进展

类固醇激素睾酮是影响鸟类繁殖最重要的性激素之一,与鸟类的繁殖行为的各个方面息息相关。睾酮通过影响鸟类的羽色、鸣声等来影响鸟类的配偶选择,同时睾酮可以调节配偶选择和繁殖投入之间的平衡。睾酮水平影响出雏数、出飞数、孵化率成功率等繁殖成效。睾酮还对个体的免疫活性和个体的存活率等产生影响。目前关于睾酮对鸟类繁殖影响的研究大多是通过外源性植入睾酮的方式来改变个体睾酮的浓度,其研究结果也常出现相互矛盾之处,对于自然状态下影响睾酮水平变化的因素尚缺乏了解,睾酮对雌雄鸟在繁殖过程中的影响也不尽相同,有必要继续深入研究。     

Estrogen-androgen antagonism in the regulation of epidermal growth factor in mouse submandibular salivary gland and kidneys

To eludicate hormonal regulation of epidermal growth factor (EGF) concentration we studied the effects in adult female mice of ovariectomy and postovariectomy treatments with testosterone plus estradiol on the EGF concentrations in submandibular salivary gland (SMG), plasma, kidneys and urine. In the tissues, we also studied the location of EGF immunohistochemically and measured EGF mRNA. After ovariectomy, SMG EGF first decreased to one third of preovariectomy level. After postovariectomy day 10 it started to increase and reached by day 80 3.5-fold the preovariectomy level. Simultaneously, EGF mRNA increased. Testosterone treatment further strongly augmented the levels of both EGF mRNA and EGF. A small dose of estradiol counteracted slightly the mRNA effect of testosterone. After ovariectomy plasma EGF first increased 1.3-fold by day 10, then returned to the initial levels, and rose again 1.6-fold by day 80. Testosterone treatment induced a further 1.5-fold increase. Estradiol did not counteract this effect. Kidney EGF decreased 15% by postovariectomy day 20. This was preceded by a decrease in EGF mRNA from day 10 onwards. The EGF concentration recovered during the 80 days, but the EGF mRNA level stayed low. Testosterone treatment further reduced the levels of both EGF mRNA and EGF. This effect was counteracted by estradiol. Urine EGF increased after ovariectomy to a peak (1.7-fold) by day 40. It then returned to the preovariectomy levels by day 80. Testosterone treatment increased urinary EGF 1.9-fold; concomitant estradiol had no effect.     

Thein vitro effect of some pesticides on the nitrogen fixing bacteria isolated from the phyllosphere of some crop plants

Summary Thein vitro effects of twelve commonly used pesticides, including the fungicides Cuman-L (Ziram) and Hinosan (Ediphenphos), the acaricides Nuvacron (Monocrotophos), Ekatin 25EC (Thiometon) and Ekalux-G₅ (Quinalphos) and other insecticides namely Dimecron (Phosphamidon), Anthio 25EC (Formothion), Baytex (Fenthion), Metasystox (Methyl demeton) and Phosalone (Zolone), on the nitrogen fixing bacteria isolated from the phyllosphere of some crop plants were tested. A very wide variation of the effect of these pesticides on the different organisms was noted. At a concentration of 700 g/ml in the medium, most of the pesticides completely inhibited growth of the nitrogen fixing bacterial isolates. However, with some pesticides, when used at a lower concentration, a degree of growth stimulation was recorded.     

Efficacy of simulated barrier treatments against laboratory colonies of Pharaoh ant

Five selected insecticides were applied to four substrates and evaluated in laboratory studies for repellency and toxicity against the Pharaoh ant, Monomorium pharaonis (L.). We tested both repellent and nonrepellent formulations on outdoor (concrete and mulch) and indoor (ceramic and vinyl) substrates. Repellency was evaluated using a behavioral bioassay in which colonies were given a choice to leave the treated zone and move into empty nests provided in the untreated zone. We used a novel experimental design whereby ants walked on a Slinky coil suspended from a metal support frame, thus permitting a long foraging distance with a minimum use of space and resources. Cypermethrin, a repellent pyrethroid insecticide, resulted in colony budding, although the response was delayed. Toxicity of insecticides was evaluated as worker, queen, and brood mortality. The most effective treatment was fipronil, which provided 100% reduction in pretreatment activity by 2 d posttreatment on both concrete and mulch. Chlorfenapyr was highly effective on both outdoor and indoor substrates. Significant substrate effects were observed with insecticides applied to nonabsorbent substrates (ceramic tile), which performed better than insecticides applied to absorbent substrates (vinyl tile). Other highly absorbent materials (mulch and concrete), however, did not reduce insecticide efficacy. This is because ants relocated nests into and/or under these attractive nesting materials, thus increasing their exposure to toxic insecticide residues. Our results demonstrate efficacy of nonrepellent liquid insecticides as indoor treatments for the control of Pharaoh ants and possibly as exterior perimeter treatments.     

Testosterone and social context affect singing behavior but not song control region volumes in adult male songbirds in the fall

Testosterone (T) induces singing behavior and mediates changes in the sizes and neuroanatomical characteristics of brain regions controlling singing behavior (song control regions, SCRs) in songbirds. These effects may require the enzymatic conversion of T into androgenic and estrogenic metabolites by brain tissues and can be modulated by factors such as season and social context. Testosterone administration to adult male House Finches, Carpodacus mexicanus, in the spring increases the size of their SCRs. Here, we used males of this species to investigate effects of T and T metabolism on brain morphology and singing behavior in the fall. Birds received Silastic capsules containing androgens, estrogens, and/or inhibitors of androgenic action or estrogen synthesis to determine effects of these hormones on song rates and SCR volumes. We also manipulated the social environment by changing the number of birds in visual contact with each other. Testosterone treatment stimulated singing behavior in finches held in small, visually isolated groups and exposed to song playbacks. However, administration of T or T metabolites did not increase SCR sizes. The data suggest that photoperiodic condition and social context may modulate the effects of steroids on SCRs and singing behavior.     

Changes in the blood and the bone marrow picture of the Pharaoh quail (Coturnix coturnix Pharaoh) chicks as a manifestation of adaptation to postembryonal life

1. The aim was determination of the rate of adaptation of the respiratory and defence functions of the blood and bone marrow of quail chicks. 2. In the early post-hatching period, enhanced haemoglobin synthesis is the mechanism adapting the bird to the rich oxygen conditions beyond the egg. 3. In 2-week-old chicks, the increased respiratory function of the blood is associated with a parallel rise of the erythrocyte count and haemoglobin content. 4. The defence mechanisms of the chick in the first days after hatching are mainly connected with a high content of heterophilic granulocytes and in older chicks with a rising lymphocyte count.     

Behavioural and Physiological Effects of Testosterone Propionate and Cyproterone Acetate in Immature Male Domestic Ducks,Anas platyrhynchos

The behavioural and morphological effects of testosterone propionate and of the anti-androgen cyproterone acetate were studied in male domestic ducks. Testosterone was also measured by radioimmunoassay in the plasma of these birds to relate the behaviour to the actual circulating levels of hormone. Testosterone stimulates sexual behaviour but has few effects on social displays. There is no correlation between the individual variations of plasma testoterone and sexual behaviour.     

Effect of neonatal injections of estradiol, testosterone and cryproterone acetate on plasma and testicular testosterone and on the genital system in adult male mice]

On day old male mice received a single injection of oestradiol benzoate, testosterone propionate or cyproterone acetate in order to study their action on testicular development, particularly testosterone secretion. Oestrogenization of newborn males leads, when the animals mature, to a high proportion or cryptorchidism, to atrophy of testes and seminal vesicles, and inhibition of spermatogenesis. Testosterone levels were reduced in the plasma. Testosterone propionate produced moderate reduction of testicular weight but spermatogenesis was not impaired. Plasma testosterone level was reduced. Cyproterone acetate increased significantly testicular testosterone level.     

Effect of dietary fish oil on mouse testosterone level and the distribution of eicosapentaenoic acid-containing phosphatidylcholine in testicular interstitium

Low levels of serum testosterone are characteristically associated with diabetes, coronary atherosclerosis, obstructive sleep apnea, rheumatoid arthritis, and chronic obstructive pulmonary disease. Testosterone replacement therapy is effective against many of these disorders, indicating the importance of maintaining a healthy testosterone level. In this study, we investigated the effects of fish oil on murine testosterone metabolism and analyzed the dynamics of relevant lipids in testes by matrix-assisted laser desorption ionization mass spectrometry imaging. Testosterone was upregulated in mice that received fish oil. In the testicular interstitium, eicosapentaenoic acid-containing phosphatidylcholine was distributed characteristically. These data suggest that eicosapentaenoic acid is involved in testosterone metabolism.     

Purported medical diagnoses of Pharaoh Tutankhamun,c. 1325 BC-

King Tutankhamun is one of the most famous rulers of antiquity, thus it is not surprising that a plethora of scientific studies have put forth possible medical diagnoses and causes of his death. Diseases (autologous or infectious), metabolic disorders, trauma (possibly even murder-related), or tumorous conditions have been postulated, frequently only based on secondary data sources. The aim of this article is to critically review all these diagnoses.     

The curse of the Pharaoh revisited: evolutionary bi-stability in environmentally transmitted pathogens

It is increasingly evident that for a number of high-profile pathogens, transmission involves both direct and environmental pathways. Much of the distinguished evolutionary theory has, however, focused on each of transmission component separately. Herein, we use the framework of adaptive dynamics to study the evolutionary consequences of mixed transmission. We find that environmental transmission can select for increased virulence when direct transmission is low. Increasing the efficiency of direct transmission gives rise to an evolutionary bi-stability, with coexistence of different levels of virulence. We conclude that the overlooked contribution of environmental transmission may explain the curious appearance of high virulence in pathogens that are typically only moderately pathogenic, as observed for avian influenza viruses and cholera.     

Coordinated interaction of neurogenesis and angiogenesis in the adult songbird brain

Neurogenesis proceeds throughout life in the higher vocal center (HVC) of the adult songbird neostriatum. Testosterone induces neuronal addition and endothelial division in HVC. We asked if testosterone-induced angiogenesis might contribute importantly to HVC neuronal recruitment. Testosterone upregulated both VEGF and its endothelial receptor, VEGF-R2/Quek1/KDR, in HVC. This yielded a burst in local HVC angiogenesis. FACS-isolated HVC endothelial cells produced BDNF in a testosterone-dependent manner. In vivo, HVC BDNF rose by the third week after testosterone, lagging by over a week the rise in VEGF and VEGF-R2. In situ hybridization revealed that much of this induced BDNF mRNA was endothelial. In vivo, both angiogenesis and neuronal addition to HVC were substantially diminished by inhibition of VEGF-R2 tyrosine kinase. These findings suggest a causal interaction between testosterone-induced angiogenesis and neurogenesis in the adult forebrain.     

The influence of testosterone administration on plasma prolactin levels in the neonatally androgenized (NA) female rat

Neonatally androgenized (NA) female rats were ovariectomized (OVX) as adults and given 1 mg of testosterone propionate/day for 7 days and the plasma prolactin (PRL) pattern compared with NA intact animals and normal OVX animals given estrogen or TP. NA intact animals had elevated basal (morning values) and an attenuated afternoon surge when compared to normal estrogen-treated animals. Testosterone administration to normal animals induced an afternoon surge similar to that of normal estrogen-treated animals but the magnitude of the surge was less. Testosterone given to NA-OVX animals had little effect on either morning or afternoon PRL levels. The results suggest that in the NA rat the brain region involved in the conversion of testosterone to estrogen may be altered by neonatal androgen exposure.     

Effect of oestrogenic, and androgenic and gestagenic hormones on the gametogenesis (oogenesis and spermatogenesis) in the snail Helix pomatia

In the ovotestis of Helix pomatia both oogenesis and spermatogenesis were influenced by treatments with steroid hormones produced in the gonads of higher vertebrates. Testosterone influenced gametogenesis to a small degree. Progesterone and oestrone-acetate at first stimulated ovogenesis, but they also acted on spermatogenesis. All three hormones examined influenced oogenesis in a conspicuous and significant way, while their effect on spermatogenesis was indistinct.