Metabolic depression induced by urea in organs of the wood frog, Rana sylvatica: effects of season and temperature

It has long been suspected that urea accumulation plays a key role in the induction or maintenance of metabolic suppression during extended dormancy in animals from diverse taxa. However, little evidence supporting that hypothesis in living systems exists. We measured aerobic metabolism of isolated organs from the wood frog (Rana sylvatica) in the presence or absence of elevated urea at various temperatures using frogs acclimatized to different seasons. The depressive effect of urea on metabolism was not consistent across organs, seasons, or temperatures. None of the organs from summer frogs, which were tested at 20 degrees C, or from winter frogs tested at 4 degrees C were affected by urea treatment. However, liver, stomach, and heart from spring frogs tested at 4 degrees C had significantly lower metabolic rates when treated with urea as compared with control samples. Additionally, when organs from winter frogs were tested at 10 degrees C, metabolism was significantly decreased in urea-treated liver and stomach by approximately 15% and in urea-treated skeletal muscle by approximately 50%. Our results suggest that the presence of urea depresses the metabolism of living organs, and thereby reduces energy expenditure, but its effect varies with temperature and seasonal acclimatization. The impact of our findings may be wide ranging owing to the number of diverse organisms that accumulate urea during dormancy. J. Exp. Zool. 309A:111-116, 2008. (c) 2008 Wiley-Liss, Inc.     

Lipid peroxide levels in a murine adenocarcinoma exposed to hyperthermia: the role of glutathione depletion.

Increased lipid peroxide levels were obtained 1 h after a 60-min 43 degrees C hyperthermia treatment of a solid murine C3H mammary adenocarcinoma, grown subcutaneously in the hind paws of mice. Previous work from our group revealed that this heat treatment depletes the intracellular glutathione (GSH) content in this tumor. To investigate GSH depletion as one tentative mechanism behind the increased lipid peroxide levels obtained, we also measured the formation of lipid peroxidation products after extensive DL-buthionine-S,R-sulfoximine (BSO)-induced GSH depletion. The lipid peroxide effect provoked by BSO was less than that of the 60-min hyperthermia treatment. We therefore propose that the increased lipid peroxide levels induced by heat treatment do not correlate primarily with the observed decrease in GSH levels. Furthermore, in thermotolerance-induced tumors, lipid peroxide levels after a second heat treatment were observed to increase concomitantly with the cessation of thermotolerance. Lipid peroxide levels were also studied in liver, lung, and heart. Following BSO treatments, and up to 2-fold increase was observed in these organs in non-tumor-bearing mice. It was also observed that the intrinsic lipid peroxide levels in these organs from tumor-bearing mice were approximately 1.5- to 4-fold higher in comparison with non-tumor-bearing mice, thus indicating a systemic effect of the tumor implant.     

On the age and growth of the freshwater eel (Anguilla anguilla)

The growth of over a 1000 eels from three different watersheds was investigated. Because of the difficulties of sexing eels we were only able to compare the size of females with that of eels with lobulate organs (some of the latter are potential females). Generally female eels grow faster than the others. There was little difference in the growth of eels with lobulate organs even though there was a great difference in the eel population density in the three localities. But, in any one locality there was a large range of growth. It is suggested that the competition for food is most acute amongst the smaller size groups. As they grow, eels tend to become cannibalistic and find small eels and elvers an easy source of food.
The growth of some continental eels has been related to temperature but this is not confirmed by experimental work. Nevertheless eels eat little or nothing at low temperature as is shown by the large percentage of eels with empty stomachs in our samples.     

Effects of estrogen on growth of androgen-responsive rat prostatic tumor (R 3327)

It has been known that estrogen has synergistic effects with androgen on growth of normal male accessory sex organs of rats. The present study was therefore undertaken to examine the effects of estrogen on androgen-responsive rat Dunning R 3327 prostatic tumor. The weight of male accessory sex organs was suppressed by estrogen on growth of treatment, but synergistic effects of estrogen and androgen on these organs were seen following combined treatment with androgen and estrogen. In contrast to the effects of estrogen on accessory sex organs, estrogen influenced a R 3327 tumor only in the negative direction regardless of whether androgen was injected simultaneously or not. When the dihydrotestosterone injection was reduced from 500 to 100 micrograms/rat/day after the tumor appeared as subcutaneous nodules, the weight of the accessory sex organs was similar to that of the control animals. However, this amount of dihydrotestosterone increased tumor growth equally when compared to those treated with a pharmacological dose of dihydrotestosterone. Therefore, the response of R 3327 tumor to androgen was different from that of the accessory sex organs.     

Fluorescence of acridine orange in the composition of blood and tissues

The interaction of acridine orange with blood albumins and tissue cells from different organs of white mouse has been studied by the spectral luminescence method. It was shown that acridine orange, by penetrating cells or organelles, is able to intercalate between base pairs in the DNA molecule. It was found that the application of acridine orange as a fluorescent probe can influence the metabolic activity of organs.     

Evaluation of the experimental pathogenicity of some Cryptococcus species in normal and cyclophosphamide-immunodepressed mice

The pathogenic potential of distinct Cryptococcus species has been evaluated in mice rendered leukopenic by one or two injections of the potent immunosuppressive drug cyclophosphamide (Cy). Pathogenicity assessment included enumeration of viable cryptococcal cells in animal organs and histopathological observations. It was found that putatively non-pathogenic species of Cryptococcus, in particular C. cereanus and C. albidus, showed significant lethality for Cy-treated mice. In Cy-immunodepressed mice, challenged with the infectious cryptococcal cells two days after pharmacological treatment, a significant decrease of LD50 (equivalent to at least one order of magnitude) was observed for all Cryptococcus species. However, the pathogenicity enhancement due to Cy immunodepression was greater with C. neoformans. In all cases, brain and kidney were the most invaded tissues as also evidenced by histopathological examination, which showed the typical cystic lesion. All the observations made point to the conclusion that the pathogenic potential, for the immunomodulated host, of Cryptococci other than C. neoformans is significant being quantitatively and not qualitatively different from that of C. neoformans, as evidenced by a similar organotropism and similar type of histological lesions in the target organs (brain and kidney).     

中生代银杏类植物系统发育、分类和演化趋向

长期以来银杏类植物化石分类都依据营养叶形态为基础。由于叶形态的多型性和异源性,导致分类和系统发育解释的紊乱。根据对保存完好的繁殖器官(胚珠器官)系统发育分析结果所作的银杏目分类表明中生代除了银杏和银杏科以外,至少还存在着3．5个已灭绝的科级单元。此方案把已知其繁殖器官的成员和仅仅根据营养器官建立起来的分类位置不明的属严格地区分开来,并注明各科的限定性特征和已知成员的地质地理分布。银杏目植物自古生代起源,至早中生代以后朝着不同的方向辐射,呈现出丰富的多样性并经历了错综复杂的演化过程,其总的演化趋向是退缩：叶片扁化、蹊化和融合;胚珠器官简化,胚珠增大、数目减少,珠柄趋于消失。     

Multiple organ mutation in the lacZ transgenic mouse (Muta mouse) 6 months after oral treatment (5 days) with benzo[a]pyrene.

We have recently demonstrated that not all organs with high rates of mutation in the lacZ transgene develop tumors using the Muta Mouse. To better understand the role of in vivo mutation in carcinogenesis, we examined the mutant frequencies (MF) of the lacZ transgene in tumor-bearing and non tumor-bearing organs. MF, recovered after 2 weeks (the data taken from our previous study) and after 26 weeks following oral doses of 125 mg kg-1 day-1 benzo[a]pyrene (BP) for five days were compared. The organs examined included the target organs (forestomach, spleen, and lung) and non-target organs (colon, glandular stomach, and liver) for BP carcinogenesis. The data indicated that lacZ MF were markedly increased over spontaneous frequencies in the organs examined and that the organ which showed the highest MF was the colon, followed by the forestomach>spleen>glandular stomach, liver, and lung in that order. These findings indicate that the MF of the lacZ transgene in each organ, even 26 weeks after the start of the treatment does not fully correlate with the known target organs of BP. Furthermore, the lacZ MF in a non-papilloma region of a forestomach with a papilloma was equivalent to the two highest MF observed in the healthy colon (non-target organ) of mice at 26 weeks. These observations also indicate that the generation of tumors requires the induction of mutations as well as other factor(s) specific to the target organs. These results clearly suggest that highly mutated organs do not always progress to tumors in the transgenic mouse.     

Evaluation of the effect of a new polyfungin derivative in chronic infection of albino mice with P-32 labeled Candida albicans

White mice, Balb/c, were infected intraperitoneally with Candida albicans strains: standard ATCC 1023 and 910 strain isolated from vaginal excretions of patient suffering from genital mycosis. One group of animals was given new Polish polyene antibiotic N-methylglucamine salt of N-glucosylpolyfungin (N-MGP). It was possible to follow a course of infection using our own experimental model of candidiasis with 32P-Candida albicans cell suspension by measuring a degree of radioactivity of organs taken from treated and untreated animals. Statistically significant lower radioactivity values (P less than 0.01) were found in organs of animals treated with N-MGP salt for 20 days in daily dose of 20 mg/kg of body weight. Therapeutic efficacy of N-MGP salt was confirmed in separate experiments where mice were infected intraperitoneally with unlabelled Candida albicans cells. Negative results of mycological examinations were found when several organs homogenates of treated mice were tested. Activity of new polifungin derivative in chronic candidiasis of mice was found using two different ways of evaluation of this new preparation.     

The patterns and expression of KDR in normal tissues of human internal organs

KDR has been implicated for playing an important role in the formation of new blood vessels and in solid tumor growth. It was considered as one of the most important regulators of angiogenesis and a key target in anticancer treatment. In the present study, we characterized KDR mRNA and protein expression in normal tissues of perinatal and adult tissues using One-step Real-Time RT-PCR and immunohistochemistry with a self-made anti-KDR antibody. The expression of KDR mRNA and protein in perinatal internal organs were all higher than in adult organs including brain, kidney, liver, lung and heart, respectively. KDR protein was presented in the cell plasma membrane of human internal tissues. The expression of KDR protein was raised in macrophage of spleen, and decreased in neurons of brain, myocardium, bronchial epithelial cells and alveolar epithelial cell, proximal and distal tubules cells, and hepatic cells with the maturity process of human organs. Notably, the order of KDR protein expression from highest to lowest is as follows: brain, liver, heart, kidney, and lung in adult tissues with statistically significant. It follows that how to balance the potential therapeutic side effect with human internal organs in targeted therapy of over-expressing KDR tumor.     

Inhibition of tumor growth in vitro by the extract of fagopyrum cymosum (fago-c)

Fagopyrum cymosum (Trev.) Meisn has long been used in China to treat various ailments of the lung, including lung tumors. This study investigated whether Fagopyrum cymosum extract (Fago-c) has effects on other organs. Human cancer cells derived from 10 different organs were employed, and their growths as affected by Fago-c were investigated. It was found that the growth of cancer cells from lung, liver, colon, leukocytes and bone is inhibited by Fago-c. However, cancer cells derived from prostate, cervix, ovary and brain are not sensitive to Fago-c, and the extract stimulates the growth of cancer cells from breast (MCF-7). Synergistic inhibition effect of Fago-c and daunomycin was observed in human lung cancer cells (H460). Cellular proteins from H460 cells treated with Fago-c were analyzed by 2D-gel electrophoresis. A protein (M.W./pI = 20K/5.9) was induced. The Fago-c extract was analyzed by High Performance Liquid Chromatography (HPLC). Four major and twenty minor components were identified. These studies indicate that the effect of Fago-c in inhibiting the growth of cell lines derived from certain organs.     

Importance of DNA repair in carcinogenesis: evidence from transgenic and gene targeting studies

We have generated transgenic mice by introducing copies of the E. coli O6-methylguanine-DNA methyltransferase gene, ada. Liver extracts from homozygotes demonstrate about three times the control enzyme activity and increase up to about eight-fold can be induced by treatment with zinc, since the metal-responsive metallothionein promoter is attached to the ada gene. Furthermore, studies of liver carcinogenesis in our transgenic mice demonstrated significantly reduced rates of development of hepatocellular tumors after treatment with dimethylnitrosamine or diethylnitrosamine. It is well known that xeroderma pigmentosum (XP) patients are deficient in DNA repair. The availability of XPA (XP group A complementing) knockout mice has enabled us to investigate the functional role of the XPA nucleotide excision repair gene in carcinogenesis in vivo, first using the mouse skin as a model system. XPA-/- mice demonstrated skin ulcers 5-7 days after 7,12-dimethylbenz[a]anthracene (DMBA) treatment and papilloma development within 4 weeks prior to promotion, skin tumor incidence being also much higher than in heterozygous and wild-type mice. Experiments targeting the lung, liver and tongue have also been conducted to answer the question of whether the internal organs of these mice are also susceptible to chemical carcinogens. For lung carcinogenesis, mice were instilled intratracheally with a small dose of benzo[a]pyrene. The pulmonary tumor incidence in XPA-/- mice was significantly higher than in XPA+/- and XPA+/+ mice. XPA-/- mice were also found to be have enhanced sensitivity to aflatoxin B1 regarding liver tumor induction. In addition, administration of 4-nitroquinoline-1-oxide in drinking water for 50 weeks resulted in tongue tumors only in XPA-/- mice. These studies, thus, provided convincing evidence that XPA mice are also sensitive to carcinogenesis in organs other than the skin.     

Investigations on the hair-digestion by dermatophyta

Summary The in vitro hair cultures of 83 strains of 22 species of dermatophytes were investigated for the presence of perforating organs by our method. It was concluded from the results that perforation is not a phyletic character, although it is of use in specific delimitation. On the ground of phyletic analyses made for the former reason the grouping of species in three groups was proposed according to their complex behaviour in respect of fructification, macroconidium-production, sexual reproduction, pathogenicity, soil-inhabitancy and occasionally performation.     

The Spinner-IBMM mouse is a new spontaneous mutant in the Tmie gene

A recessively inherited, spontaneous mutation named Spinner-IBMM (SI) was identified in a transgenic mouse colony in our institute. SI mutant mice displayed hyperactivity, including a severe circling behavior, ataxia and inability to swim. Gene mapping revealed that the causative gene was located on a 35 Mb DNA fragment on chromosome 9. Candidate genes sequencing in this DNA fragment identified a new mutant allele in the Tmie gene. The identified mutant is characterized by a nucleotide deletion in exon 5, leading to a frameshift and a premature STOP codon. It has been reported that inactivating mutations in the mouse Tmie gene result in an identical phenotype, probably resulting from defects in the inner ear. However, the exact function of the Tmie protein in the ear and other organs is still unknown. The analysis of this new mouse mutant could contribute to a better understanding of Tmie functions in vivo in the ear and other organs.     

Influence of dietary cadmium on the distribution of the essential metals copper,zinc and iron in tissues of the rat

The effect of long-term dietary cadmium treatment upon the distribution of the metals copper, iron and zinc has been compared in various organs of male and female rats. The renal accumulation of cadmium was similar in both sexes without a plateau being reached. In contrast, the hepatic accumulation of cadmium was higher in the female than in the male rat and a plateau was observed after 30–35 weeks of dietary cadmium treatment. Most of the cadmium which accumulated in these organs was recovered in the metallothionein fraction and the concentration of hepatic cadmiumthionein in the female rat was correspondingly higher than in the male rat. Accumulation of cadmium was associated with an increased zinc concentration in the liver and an increased copper concentration in the kidney; these increases were correlated with increases in liver and kidney metallothioneins induced by cadmium. Uptake of cadmium into organs other than liver and kidney occurred to a small extent but was not associated with changes in the concentration of copper and zinc. Cadmium also accumulated in the intestinal mucosa where it could be recovered in a fraction corresponding to metallothionein. A loss of iron from the liver and kidney was also observed following dietary cadmium treatment and involved mainly a loss of iron from ferritin.     

Relationship Between Male Fertility and Endogenous Phytohormones in Photoperiod-Sensitive Genic Male-Sterile Rice

A spontaneous male sterile rice plant (Oryza sativa L. cv. Nongken 58S) "Photoperiod-sensitive Genic Male-sterile Rice has been found to be male sterile under long day cycles (LD) and fertile in short day cycles (SD). The period from secondary rachis-branch and spikelet primodia to pollen mother cell formation in the process of panical development was the photoperiod-sensitive stage for fertility alternation. The phenotype of this mutant was reported to be controlled by two pairs of recessive alleles. The research on relationship between the fertility alternation and phytohormone action in this mutant have been performed by Chinese scientists since 1985. In order to study the mechanism of fertility alternation in Nongken 58S, endogenous IAA, ABA, GA1 and GA4 in apical leaves and reproductive organs in different development stages under LD and SD conditions have been quantiatvely and qualitatively identified by GC-MS-SIM method. It was found that endogenous IAA in apical leaves at the stage of pistil and stamen primodia formation and in panicles at pollen mother cell stage of Nongken 58S with LD condition was deficient comparing with those in SD. Endogenous ABA level in panicles at pollen mother cell stage, in spikelets at uninucleate stage and in anthers at anthesis stage of Nongken 58S-LD were lower than those in SD. ABA levels in corresponding organs and developmental stages of wild type of rice, "Nongken 58" were always higher in LD treatment than those in SD. Endogenous IAA, GA1 and GA4 levels in anthers at anthesis stasge of "Nongken 58"-LD were increased obviously. Thus it appeared that "Nongken 58" possess stronger resistance to LD stress than Nongken 58S. It is concluded that IAA deficiency of reproductive organs at early developmental stage, ABA decrease implying poor resistance to LD stress and reduction of GAs in late developmental stages were the factors causing the anther sterility in Nongken 58S-LD.     

Repair and replication of DNA in rat and mouse tissues in relation to cancer induction by N-nitroso-N-alkyl-ureas

The high susceptibility of certain organs, for example rat brain, to induction of cancer by N-nitroso-N-alkyl-ureas, has been related to a low ability to remove O⁶-alkylguanine (O⁶AG) from DNA. It is therefore reasonable to ask why mouse brain, in which there is also a slow disappearance of O⁶AG from DNA after treatment with nitroso-alkyl-ureas, is not susceptible and why, in mice, thymus and lung are the main target organs. The explanation of the species difference could lie in the fact that replication of alkylated DNA is an essential event in initiation. If nitroso-alkyl-ureas had a greater inhibitory effect in some organs than in others, replication might be inhibited until after the O⁶AG had been removed, so preventing replication of DNA while still alkylated. This concept was tested by comparing the effect of N-nitroso-N-methyl-urea (NMU) on incorporation of [³H]TdR into DNA of relevant organs in Wistar rats and C57BL mice, and by determining ability to remove O⁶AG from DNA by measuring the alkyl acceptor protein (AAP) concentrations in these organs. No evidence was obtained that the AAP content was lower or inhibition of replication was less extensive in the organ of the species more susceptible to carcinogenesis than in the same organ of the less susceptible species.     

Adrenaline in various organs of the rat: its origin, location and diurnal fluctuation

In order to examine the origin and location of adrenaline in peripheral organs of mammals, adrenaline and noradrenaline were measured in several organs of the rat after adrenalectomy, guanethidine treatment and imipramine injection. One week after bilateral adrenalectomy, adrenaline disappeared almost completely from the heart, spleen and submaxillary gland. Chronic administration of guanethidine caused decreases in both noradrenaline and adrenaline in the peripheral organs. Injection of imipramine induced a reduction of adrenaline concentration in the spleen and submaxillary gland. It is considered that adrenaline in the peripheral organs of mammals is mostly derived from the adrenal gland and that circulating adrenaline is taken up by sympathetic nerve endings in the organs. The adrenaline content of the peripheral organs increased after electric foot-shock and changed according to the time of day. The peak of the circadian rhythm appeared about 6 hours after the peak of the urinary adrenaline rhythm. These findings suggest that adrenaline in body organs plays some role in the responses of the sympathetic nervous system to stressful conditions or even to daily activities.     

The behavioural role of pit organs in the epaulette shark

Epaulette sharks Hemiscyllium ocellatum in three treatments, pit organs (free neuromasts) ablated, sham-operated and normal ( n  = 8 for each treatment), showed a significant preference for facing upstream in a flume ( P  < 0·05). There were no significant differences in the mean angles or angular variances among treatments. Individuals with ablated pit organs, however, spent significantly less time moving around than controls ( P  < 0·05), suggesting that pit organs contributed to motivation for activity. Pit organs do not appear to make an important contribution to rheotaxis in H. ocellatum . It is suggested that this may be due to structural differences in the pit organs of H. ocellatum compared with other species.     

Taste sensitivity in homeotic mutants of the drosophila leg-arista-wing complex

It is well established that taste chemoreceptors in Drosophila are located on the tarsi of the first leg pair. In order to investigate the influence of the novel homeotic arista-tarsus transformation on behavior, an analysis of taste perception in the lawc-mutants, characterized by the transformation of the arista into tarsus elements, was carried out. The data were subjected to thorough statistical treatment. It was shown that elements of an additional leg that appeared as a result of homeotic transformation of the arista were sensitive to gustatory stimuli. Analysis of the innervation of the homeotic organs by means of cobalt staining of afferent projections showed that the afferents starting from the homeotic leg reached the thoracic ganglion.