Disrupting the establishment of polarizing activity by teratogen exposure.

Between days 9.5 and 10, the forelimb buds of developing murine embryos progress from stage 1 which are just beginning to express shh and whose posterior mesoderm has only weak polarizing activity to stage 2 limbs with a distinguishable shh expression domain and full polarizing activity. We find that exposure on day 9.5 to teratogens that induce the loss of posterior skeletal elements disrupts the polarizing activity of the stage 2 postaxial mesoderm and polarizing activity is not subsequently restored. The ontogeny of expression of the mesodermal markers shh, ptc, bmp2, and hoxd-12 and 13, as well as the ectodermal markers wnt7a, fgf4, fgf8, cx43, and p21 occurred normally in day 9.5 teratogen-exposed limb buds. At stage 3, the treated limb apical ectodermal ridge usually possessed no detectable abnormalities, but with continued outgrowth postaxial deficiencies became evident. Recombining control, stage matched limb bud ectoderm with treated mesoderm prior to ZPA grafting restored the duplicating activity of treated ZPA tissue. We conclude that in addition to shh an early ectoderm-dependent signal is required for the establishment of the mouse ZPA and that this factor is dependent on the posterior ectoderm.     

Docosahexaenoic acid is potent against the growth of mature stages of Plasmodium falciparum; inhibition of hematin polymerization a possible target

The present study investigates the potential effect of externally added unsaturated fatty acids on P. falciparum growth. Our results indicate that polyunsaturated fatty acids (PUFAs) inhibit the growth of Plasmodium in proportional to their degree of unsaturation. At higher concentration the PUFA Docosahexaenoic acid (DHA) induces pyknotic nuclei in infected erythrocytes. When Plasmodium stages were treated transiently with DHA, the ring stage culture recovered from the drug effect and parasitemia was increased post DHA removal with delayed growth of 12 h, compared to untreated control. Schizont stage treated culture displayed a 36 h delay in growth to infect fresh erythrocytes signifying its recovery is less than the ring stage. However the trophozoite stage failed to recover and showed a decrease in parasitemia, similar to that of continuous treated culture. PUFAs inhibited β- hematin polymerization by binding to free heme derived from hemoglobin degradation. Digestive vacuole neutral lipid bodies, which are pivotal for β- hematin polymerization, decreased and subsequently abrogated with increasing concentration of DHA in trophozoite stage treated culture. Our study concludes that DHA interacts with heme monomers and inhibits the β- hematin polymerization and growth of mature stages i.e., trophozoite and schizont stages of plasmodium.     

Carcinoma of the cervix

Studies by eminent surgeons to reevaluate the place of radical operations in the treatment of carcinoma of the cervix-now that extensive procedures have become less hazardous-apparently have led to confusion in some minds as to choice between surgical and radiation therapy. Pending outcome of the studies, general employment of surgical treatment is unwarranted. Radiation is the treatment of choice in most cases, particularly if the lesion is in an early stage, although radical operation is indicated in certain rare early cases in which delivery of an effective dose of radiation to involved areas is technically difficult. Elsewise it appears at present that operation should be used only in cases of stages III or IV carcinoma-in which results by either means of treatment are poor.One hundred and seven patients were treated with a combination of x-ray and radium irradiation. X-ray was used first to reduce the hazard of implanting the radium. The "five-year arrest" rates were as follows: For 22 patients with stage I lesion, 70 per cent; for 31 with stage II, 55.7 per cent; 33 with stage III, 39.7 per cent; 21 with stage IV, 0. Eighteen patients with diagnosis of carcinoma of the cervix who had had subtotal hysterectomy were treated. The stage of the disease could not be determined. In this group the five-year arrest rate was 52 per cent.     

Relationship between stimulatory effect of methyl jasmonate on ethylene production and 1-aminocyclopropane-1-carboxylic acid content in tomatoes

The effect of methyl jasmonate (JA-Me) applied in concentration 1.0 % in lanolin paste to detached tomato fruits at the mature green, advanced mature green and light red stages on the ethylene production and l-aminocyclopropane-l-carboxylic acid (ACC) content was investigated at different times after treatment. JA-Me stimulated ethylene production in all stages of ripening, but the level of ACC increased or decreased in comparison with control depending on the stage of ripening. Higher level of ACC in JA-Me treated tissue was found in mature green stage and fully ripened tomatoes-treated at advanced green stage; lower one in light red stage — treated at advanced green stage and fully ripened stage - treated at light red stage.     

Influence of cortisol along the pituitary‐ovary axis in the cichlid fish Oreochromis mossambicus

Cortisol is the principal glucocorticoid released due to various forms of environmental as well as aquacultural stressors in fish. The aim of the present investigation was to determine cortisol‐induced alterations along the luteinizing hormone (LH)‐secreting cells–ovary axis in the tilapia Oreochromis mossambicus. Administration of cortisol to stripped O. mossambicus for a period of 22 days during the ovarian cycle caused significantly higher number of follicles with chromatin nucleoli (stage I) compared to those of initial controls and controls. Whereas the number of follicles at perinucleolar (stage II) and vitellogenic (stage IV) stages did not differ significantly between controls and cortisol‐treated fish, the number of follicles at cortical alveolar stage (stage III) was significantly lower in cortisol‐treated fish than in controls. While the stage V follicles (maturation stage) were absent in initial controls, their presence in controls was concomitant with intensely labelled LH‐secreting cells in the proximal pars distalis (PPD) region of the pituitary gland during prespawning phase. However, cortisol‐treatment resulted in complete absence of stage V follicles associated with weakly immunoreactive LH‐content in the PPD region of the pituitary gland during prespawning phase. These results suggest that chronic cortisol‐ treatment causes suppression of LH‐secreting cells activity and blocks progression of vitellogenic follicular development process in O. mossambicus.     

Effect of prostaglandin F2alpha dosage and stage of estrous cycle on the estrous response and corpus luteum function in beef heifers

Ninety-five normal cyclic crossbred beef heifers were used to determine if the proportions of heifers showing estrus, intervals to estrus and corpus luteum (CL) function were influenced by PGF(2alpha) dosage and (or) the stage of luteal phase when PGF(2alpha) was administered. Heifers were assigned randomly to treatments in a 4 x 3 factorial arrangement. Treatments were 5, 10, 25 or 30 mg PGF(2alpha) injected either in early (5 to 9 d), mid (10 to 14 d) or late (15 to 19 d) stages of the luteal phase. Jugular samples were taken at 0 h and at 8 h-intervals for 48 h and again at 60 h after PGF(2alpha) treatment for progesterone assay. Heifers were observed for estrus continuously for 120 h PGF(2alpha) treatment. The proportion of heifers showing estrus was dependent upon (P<0.05) both dosage of PGF(2alpha) and stage of luteal phase. Heifers given 5 mg of PGF(2alpha) showed estrus only if treated during the late stage, while those given 10 mg of PGF(2alpha) showed a progressive increase of heifers in estrus as stage of luteal phase advanced. The proportion of heifers showing estrus after 25 and 30 mg of PGF(2alpha) increased from 56% for the early stage to 100% for the mid and late stages. Interval to estrus in heifers showing estrus within 120 h after PGF(2alpha) treatment did not differ (P>0.05) among dosages but tended (P=0.10) to be longer in heifers treated during the mid luteal stage (67 h) than in heifers treated in the two other stages (56 h). A greater proportion of heifers (P<0.05) showed estrus by 60 h after PGF(2alpha) when treated during the early and late luteal stages (75.5%) than for heifers treated during the mid luteal stage (30.4%). Patterns of progesterone concentrations were influenced (P=0.08) by the three way interaction of dosage, stage and time. In heifers that showed estrus, rate of decline in progesterone tended (P=0.07) to be slower during the mid luteal stage than during the early and late stages. Progesterone did not drop below 1 ng/ml until 32 h in heifers treated during the mid luteal stage; whereas progesterone dropped below 1 ng/ml by 24 h in heifers treated during the early and late stages. These data may be useful in designing more efficient systems for using PGF(2alpha) or its analogues in estrus synchronization of beef cattle.     

The influence of hypotonic treatment on the morphology of meiotic stages I. Prophase of the first meiotic division of male mice,man and Locusta migratoria

Male mice were treated with hydroxyurea (HU) to obtain a restricted germ cell population and a sequential analysis of the first meiotic prophase was performed. The results from HU-treated mice were compared with those from untreated mice, human and grasshopper material with and without hypotonic treatment.In hypotonically treated material the three subclasses of diffuse stages were obvious in all species investigated. In material not treated hypotonically the different classes of prophase stages showed a more gradual course, there was a tendency towards less spreading of the bivalents and no pronounced diffuse substages could be found. The first desynaptic stage in this material could be recognized in most cases as wellspread classical pachytene like bivalents with a pronounced double-threaded structure. The more advanced desynaptic stage in untreated material resembled the diffuse stage as found in plant meiosis.     

Diagnosis and therapy of primary extranodal non-Hodgkin's lymphoma of the stomach

In the period from 1970-1980 120 patients with NHL were treated. A primary stomach manifestation could be detected in 6.6%. Problems of pre-operative, endoscopic-bioptic diagnostics are discussed and recommendations for a therapeutic proceeding are given. The tumour is surgically removed at stage I and II, which is always followed by polychemotherapy. Primary polychemotherapy is used at stages III and IV. Patients at stage II achieved a complete remission, those at stage IV died within 6 months after diagnosis.     

雷公藤总生物碱对粘虫幼虫神经系统酶活性及神经递质含量的影响

【目的】明确雷公藤Tripterygium wilfordii Hook. f.生物碱对粘虫Mythimna separata (Walker)神经系统的影响,为阐明其杀虫作用机制提供依据。【方法】采用载毒叶片法测定粘虫5龄幼虫经雷公藤总生物碱处理后体内乙酰胆碱酯酶（AChE）、Na⁺, K⁺-ATPase、Ca²⁺, Mg²⁺-ATPase、谷丙转氨酶（GPT）和谷氨酸脱羧酶（GAD）等重要神经系统酶活性及乙酰胆碱（ACh）、谷氨酸（Glu）和γ-氨基丁酸（GABA）等神经递质的含量。【结果】雷公藤总生物碱处理对粘虫5龄幼虫AChE无明显影响,麻醉期处理粘虫幼虫体内ACh相对含量与同期对照无显著差异。处理粘虫幼虫在轻度麻醉期、深度麻醉期和复苏期体内GABA和Glu含量显著升高,GABA含量分别升高了89.86%, 49.28%和20.29%,Glu含量分别升高了24.55%, 23.33%和8.13%。处理粘虫幼虫GPT活性明显受到抑制,而GAD活性无明显变化。处理明显抑制粘虫幼虫头部Na⁺, K⁺-ATPase和Ca²⁺, Mg²⁺-ATPase活性,但对中肠两种ATPase活性影响不大。【结论】研究结果有助于了解雷公藤生物碱对昆虫神经系统的影响,也为进一步阐明其作用靶标奠定了基础。     

Induction and activation of meiosis and subsequent parthenogenetic development of growing pig oocytes using calcium ionophore A23187

The pig ovary contains a large number of growing oocytes, which do not mature in vitro and cannot be readily used in various biotechnologies. This study was conducted to determine the possibility of inducing meiotic maturation in growing pig oocytes with an internal diameter of 110 μm, which had developed partial meiotic competence. Most of these oocytes spontaneously stopped maturation at the metaphase I stage (68%); a limited number proceeded to the metaphase II stage (26%). Treatment with calcium ionophore A23187 (50 μM for 5 or 10 min) after 24 h in vitro culture overcame the block at the metaphase I stage, and treated growing pig oocytes matured to the metaphase II stage (66%). Oocytes in which maturation had been induced by calcium ionophore were again treated with calcium ionophore. Up to 58% of the treated oocytes were activated. Parthenogenetic development in oocytes treated with ionophore for meiosis induction and activation was very limited. The portion which reached morula stage did not exceed 8% and at most 3% developed to the blastocyst stage.     

Energy requirement for the initiation of colicin action in Escherichia coli

1. Starved cells of a strain of Escherichia coli and its mutant uncA, treated with colicin K, E2 or E3, remained fully rescuable upon trypsin treatment (stage I in colicin action). The transition to stage II in colicin action (cells no longer rescuable by trypsin) was promoted by the addition of either glucose or d-lactate.2. Aerobically glucose-grown cells of the normal strain were irreversibly killed by colicin K, E2 or E3 under anaerobic conditions, while similarly treated cells of its mutant uncA remained fully rescuable. The stage I-stage II transition in colicin action was blocked in normal cells under anaerobic conditions when succinate was the sole carbon source.3. Arsenate alone had little effect on the progression of the stage I-stage II transition in normal cells, treated with colicin K. However, this transition was abolished in the presence of both arsenate and anaerobic conditions.4. The initiation of colicin action could be coupled to the anaerobic electron transfer systems formate dehydrogenase-nitrate reductase and α-glycerophosphate dehydrogenase-fumarate reductase.5. These results indicate that an energized state of the cytoplasmic membrane is required for the initiation of colicin action and that no high-energy phosphorylated compounds are necessary.     

The hormone content of ripening grape berries and the effects of growth substance treatments

Berries on field-grown Vitis vinifera cv. Doradillo were treated at different times during stage II with benzothiazole-2-oxyacetic acid or 2-chloroethylphosphonic acid, and measurements were made of their growth and hormone content. The concentration of ethylene was low during stage II and declined as berries ripened. Both 2-chloroethylphosphonic acid and benzothiazole-2-oxyacetic acid caused increases in ethylene concentration, yet they had varying effects on ripening: the former applied at the start of stage II and the latter applied 1 week before the end of stage II delayed ripening, while 2-chloroethylphosphonic acid applied at the end of stage II hastened ripening.     

水浸对越北腹露蝗卵的影响

越北腹露蝗Fruhstorferiola tonkinensis Will.是广东北江流域河滩蝗虫的优势种。以不浸水的蝗卵为对照,研究滞育期蝗卵浸水5～95d和胚胎发育期蝗卵浸水1～30d对卵孵化率和历期的影响。结果表明,随浸水时间的增加,孵化率下降,卵发育延迟;滞育期蝗卵经受95d的浸水仍有8.01%存活,而胚胎发育期蝗卵浸水30d后全部死亡,滞育期蝗卵比胚胎发育期蝗卵具有更强的耐浸水能力。说明越北腹露蝗以卵滞育的形式发展了对水浸胁迫的适应。     

Ketoconazole in the treatment of experimental murine paracoccidioidomycosis

In a murine model of chronic disseminated paracoccidioidomycosis (strain 18; intravenous route), Ketoconazole (200 mg/kg in 0.2% agar) was given daily by gavage in three different schedules. Continuous treatment from an early stage of infection (day 3) up to week 20 was the most effective protocol, leading to remission of histopathological lesions and of both humoral and cellular anti-P. brasiliensis immune response, and clearance of the fungus in lungs; only 1 treated animal at week 20 showed pulmonary granulomas, although less extensive than control mice. Continuous treatment from early stage up to week 8, followed by a 16 week-period of drug discontinuity, caused remission of lesions in all but 3 treated mice which showed active pulmonary paracoccidioidomycosis similar to controls (14.2% of unresponsiveness to treatment). The continuous Ketoconazole protocol since a late stage of infection (week 4) up to week 20 produced a slower remission of lesions and immune response when compared with the first drug schedule. In this model of paracoccidioidomycosis, Ketoconazole showed no detectable side-effects and was a very effective drug especially in a prolonged administration protocol from an early stage of infection.     

Hypotonic buffer induces meiosis and formation of anucleate cytoplasmic islands in the egg of the two-spotted cricket Gryllus bimaculatus

In insects, egg activation is known to occur in vivo and independently of fertilization, but its mechanisms are poorly understood. To gain understanding of these mechanisms, an attempt was made to activate the egg of Gryllus bimaculatus in vitro. It was found that meiosis resumed and was completed in unfertilized eggs treated with hypotonic buffer. Early developmental processes in activated, unfertilized eggs were investigated and compared with those in fertilized eggs. Mitosis did not progress, resulting in formation of anucleate cytoplasmic islands (pseudoenergids). Development in the activated, unfertilized eggs stopped at this stage and both yolk subdivision and cellularization did not occur. To elucidate the role of the nucleus in the developmental process to the syncytial stage in fertilized eggs, eggs were treated with aphidicolin to inhibit DNA polymerization. It was found that pseudoenergids also formed in these aphidicolin-treated fertilized eggs. These results demonstrate that pseudoenergids can increase in number independently of nuclei, suggesting that the cytoplasm rather than the nucleus plays the primary role in development to the syncytial stage in G. bimaculatus.     

非嗜食寄主气味蛹期处理对不同寄主来源美洲斑潜蝇雌成虫嗅觉定向的影响

测定用菜豆和丝瓜饲养的美洲斑潜蝇Liriomyza sativae Blanchard蛹暴露于用正己烷稀释的番茄或南瓜叶片挥发性抽提物(TLE或PLE)72h后,羽化雌成虫在Y形嗅觉仪中对TLE或PLE的定向率、平均反应时间以及对正己烷的定向率和平均反应时间,比较幼虫寄主经历和寄主气味对美洲斑潜蝇成虫嗅觉记忆的影响。结果表明,蛹期使用非嗜食寄主植物气味处理,能增加美洲斑潜蝇羽化雌成虫对非嗜食寄主气味的定向;幼虫期的寄主经历对处理后的成虫嗅觉定向也产生影响,饲喂丝瓜的美洲斑潜蝇蛹期处理后,羽化雌成虫显著偏向选择处理气味而非正己烷,饲喂菜豆的美洲斑潜蝇对南瓜的气味也表现出同样的特点,但对番茄的气味则相反,即使处理后对番茄气味的选择比率增加,仍然偏向选择正己烷。     

Single-stranded regions in DNA isolated from different developmental stages of the sea urchin

Long-term labeled sea urchin embryo (Strongylocentrotus purpuratus) DNAs were examined for size of recovered pieces, single-strandedness, and length of continuous double-stranded regions. Sizing on neutral sucrose gradients indicates that morula stage DNA sediments predominantly at 31 S, blastula stage DNA at 27 S, and gastrula stage DNA as a broad range of sizes of greater than 29 S. Treatment of [3H]thymidine-labeled DNA with Aspergillus oryzae S1 nuclease removes 19% of the 3H from morula stage DNA, 4% of the 3H from blastula stage DNA, and less than 0.1% of the 3H from gastrula stage DNA. Sedimentation of S1 nuclease treated [3H]DNAs on alkaline sucrose gradients indicates that in native morula stage DNA there is a nick or gap in one strand approximately every 9700 base pairs, in native blastula stage DNA about every 3300 base pairs, and very few nicks or gaps in native gastrula stage DNA.     

Fluorescent detection of APUD-type cells in the digestive tract of the rabbit fetus. Correlative study in electron microscopy

Previous studies performed on different species have shown that these cells could be recognized by their morphologic and immuno-histological features. In early stages, these cells are able to take up and decarboxylate amine precursors. Therefore the aim of the present work was to determine if this uptake could be correlated with ultrastructural modifications. A processing technique allowing amine detection and correlative ultrastructural examination was used. Rabbit foetuses 13, 14, 17 and 21 day old were studied. The gastro-intestinal tracts of L-DOPA treated or untreated foetuses were removed in a glutaraldehyde-formaldehyde mixture and embedded in epoxy-resin. Semi-thin sections allowed to locate fluorescent cells in U.V light microscopy; adjacent thin sections were observed in electron microscopy. The first green fluorescent cells appeared in the 13 day old foetuses treated with L-DOPA. By this stage, these cells were very scarce and appeared poorly differentiated in electron microscopy. Between the 15th and the 18th day, the green fluorescent cells contained only small round granules. By the day 19, orange-yellow cells can be observed in L-DOPA treated and untreated foetuses. These cells possessed characteristic enterochromaffin granules. The green fluorescent cells of 21 day old foetuses, treated with L-DOPA, exhibited various fluorescence intensities correlated with the heterogeneity of the secretory granules. Some foetuses of each stage were treated with Falck's technique. This method gave similar results concerning the chronology of fluorescent cell detection.     

Hormonal Changes Associated with Growth and Development of Red Raspberries

Analysis for gibberellin-like substances (GA) and cytokinins in cold and non-cold treated fall-bearing and cold treated June-bearing cultivars of red raspberries (Rubus idaeus L.) was made at the 10 and 20 node stages of growth (at 10 nodes, all plants were vegetative; at 20 nodes, only cold treated plants of fall-bearing cultivars were flower induced). Quantitative changes in GAs, as analyzed by the lettuce hypocotyl bioassay, were observed only in flower induced plants. In fall-bearing cultivars at the 20 node stage of growth, there was a 100% greater activity in cold than non-cold treated plants. Likewise, cold treated plants had a 60% greater activity at the 20 than at the 10 node stage of growth. Major qualitative differences in GAs were observed between the 10 and 20 node stage of growth in cold treated fall-bearing cultivars but not in cold treated plants of June-bearing cultivars. Changes in compounds at R_f 0.3 and 0.5 accounted for 35 to 54% of the total increase in GA activity between flower induced and non-induced stages of growth. Cytokinin activity tested by the tobacco callus bioassay was greater at the 20 than at the 10 node stage of growth in all cultivars and treatments. However, cold treated plants of the fall-bearing type had 70% greater cytokinin activity than non-cold treated plants at both stages of growth. It is suggested that gibberellins, possibly acting synergistically with cytokinins, are involved inflower induction in red raspberries.     

A quantitative evaluation of the changes in the proliferation of a human lymphocyte culture after mutagen exposure at the G0 stage

Cell cycle delay of human lymphocytes treated with mutagens at G0 stage has been studied using a mathematical model. Cell cycle delay depends on entry cells into the first S phase and is independent on the cell cycle duration.