Effects of tritoqualine on hepatic and blood levels of histamine after partial hepatectomy in rats]

Looked as a specific inhibitor of histidin-decarboxylase, tritoqualine has been injected subcutaneously to Wistar rats immediately after partial hepatectomy and, then, once in 24 hours until 72 hours. It has thus provoked : an unexpected, but transient rise (reaching its apex 3 hours after the operation) of the hepatic and blood histamin concentrations ; then, the expected decrease (more durable and greatest at 48 hours) of the same concentrations. Therefore, an effect of tritoqualine on the liver regeneration might be expected, whether histamin plays some part in this phenomenon.     

Sulfated glycosaminoglycans (GAG) in the developing mouse brain : Quantitative aspects on the metabolism of total and individual sulfated GAG in vivo

Sulfation and desulfation of total glycosaminoglycans (GAG) as well as of chondroitin sulfates (A + C), dermatan sulfate, and heparan sulfate were quantified in the developing cerebrum and cerebellum of mice by labeling with [35S]sulfate combined with chases started 24 hr after [35S]sulfate injection. In both the developing cerebrum and cerebellum, the rate of biosynthesis of total sulfated GAG was highest shortly after birth (2 days), decreased sharply thereafter, and reached a plateau after 14 days. The biosynthetic activities of chondroitin sulfates and heparan sulfate decreased sharply up to 14 days and retained constant levels afterward. By contrast, the rates of biosynthesis of dermatan sulfate increased up to 14 days. The biodegradation rates of total sulfated GAG as well as of chondroitin sulfates, heparan sulfate, and dermatan sulfate were strongly correlated with the corresponding rates of biosynthesis during the first 2 postnatal weeks. Total and individual sulfated GAG showed high degradation rates resulting in half-life times of a few hours up to 1 1/2 days. Thus sulfated GAG are synthesized in excess and the actual net content seems to be co-regulated to a high degree by lysosomal degradation. In both brain parts, a proportional increase of the sulfated GAG content vs the total GAG content from 40% at birth to 90% at 28 days was observed. Since during development heparan sulfate and dermatan sulfate manifested a relative increase in their daily net synthesis besides a decrease of chondroitin sulfates, a developmental increase of the sulfate groups linked to GAG is evidenced. This molecular differentiation resulting in microenvironmental changes may be of high functional significance.     

Relationship between oxygen uptake rate and time of infection of Sf9 insect cells infected with a recombinant baculovirus

Oxygen uptake rates (OUR) of Sf9 insect cells propagated in a serum-free medium (SF900II, Gibco) and of cells infected with a recombinant AcNPV were investigated before and after infection in a laboratory-scale bioreactor. The volumetric OURs of uninfected and exponentially growing cells were found to be proportional to the cell density. For infected cultures, the specific OUR of cells increased immediately after addition of virus and a maximum of 1.3 times the value of uninfected cells was noted for all the cultures between 8 to 30 hours post infection, which coincides with the period at which most viral replication and the majority of DNA synthesis takes place. It was observed that the rate of rise in the specific OUR decreased as the cell density at the time of infection increased, which meant that the later the infection, the later the maximum sOUR was observed. We therefore suggest that OUR measurement can be used to reflect the efficiency of a batch infection. Carbohydrate and amino acid consumption rates from an infected run were analysed in an effort to identify substrate(s) that may be used at increased rates to fuel the rise in oxygen demand observed early in the infection cycle. No observable rise in the consumption rates of glucose or glutamine, which are the major energy sources for animal cells, were seen after infection but an increase in the consumption rates of some amino acids suggests that infected Sf9 cells may utilise amino acids at an enhanced rate for energy post infection.     

注射光合细菌后罗氏沼虾血细胞组成的变化

以光合细菌作为刺激物,对罗氏沼虾进行肌肉注射,在注射后12、24、36、48、60h依次从罗氏沼虾心脏取血,用改良后的瑞氏染色法制成血涂片,光镜观察罗氏沼虾血细胞组成的变化.结果发现罗氏沼虾透明细胞在循环血细胞中所占地比例由正常状态下的66.62%略微下降至60%左右;36h左右所占比例急剧下降到30%左右;48h左右开始逐步回升;60h恢复至55%;接受刺激后的变化遵循缓慢下降、急剧下降、缓慢回升的过程.     

Disaccharidases in the small intestine of the mouse: normal development and influence of cortisone, actinomycin D, and cycloheximide

The development of maltase, sucrase, and lactase activity has been examined in the small intestine of the mouse. After increasing during 2 days before birth, maltase remains unchanged for 14 days, after which activity surges up throughout the intestine. Sucrase is absent during the first 14 days, but then rises in a pattern similar to, but distinct from, that for maltase. Both enzymes rise faster in the proximal third of the intestine than in the terminal third. Lactase, which is high in the infant intestine, falls after 12 days in the proximal segment, but only after 16 days in the more posterior segments.Cortisone administered at 8 days causes a rise of maltase activity that continues for at least 72 hours. At 4 days the same treatment causes an increase that ceases after 48 hours. Sucrase activity is elicited by cortisone at 8 days but not at 4 days. Between 10 and 13 days both actinomycin D and cycloheximide evoke significant increases of both maltase and sucrase activity in all regions of the intestine. When administered in concert with cortisone, actinomycin D inhibits, but does not prevent, the stimulatory influence of the hormone on sucrase; with maltase activity, significant inhibition occurs only in the middle third of the intestine. Cycloheximide does not interfere with the effects of cortisone. No additive effects between hormone and antibiotics were obtained.These results are discussed in relation to results of similar studies on intestinal alkaline phosphatase and leucylnaphthylamidase.     

The comparative effects of feeding ammonium carbonate, ammonium sulfate, and ammonium chloride on urinary calcium excretion in the rat

When either sulfate or chloride is added to the diet, the resulting acid load causes a rise in urinary calcium excretion. There is, however, the possibility that sulfate, which has been shown to complex renal tubular calcium, will further decrease renal calcium reabsorption and thus produce a greater calciuria than chloride. Because addition of a fixed cation (e.g., sodium) to the diet may also stimulate calciuresis, experiments were conducted using metabolizable ammonium to minimize cation effects. Ammonium salts of sulfate, chloride, and carbonate (control) were added to the diets of male rats at 0.3 mequiv./g weight of diet. Twenty-four hour excretion rates of calcium, sulfate, chloride, and net acid were measured at various intervals up to 1 month. As expected, the chloride and sulfate diets were both associated with significantly elevated urine calcium and net acid excretion as compared with controls. However, those fed sulfate exhibited significantly less calcium and acid excretion and absorbed a smaller proportion of the anion load than those given chloride. In a second experiment, the amounts of supplemental sulfate and chloride were adjusted so that total absorptions were similar. At 2 weeks, both calcium and acid excretions in the fixed anion groups were no longer significantly different. Thus, in chronic feeding trials, there appears to be no measurable difference in the calciuretic properties of sulfate and chloride anions.     

Effect of colchicine and demecolcine on the serum ceruloplasmin level in rats.

Six hours after the administration of demecolcine (0.3 mg/100 g b.w.), a decrease in the ceruloplasmin level was recorded in rat serum. The time course of the decrease in the rat serum ceruloplasmin concentration after the same dose of colchicine was then studied. After two to three hours, the serum ceruloplasmin concentration fell significantly in both male and female rats. Eight hours after the administration of colchicine, the serum ceruloplasmin level began to rise again in female rats, but not in male rats. Mortality among females was lower than among males.     

Changes in the levels of major sulfur metabolites and free amino acids in pea cotyledons recovering from sulfur deficiency

Changes in levels of sulfur metabolites and free amino acids were followed in cotyledons of sulfur-deficient, developing pea seeds (Pisum sativum L.) for 24 hours after resupply of sulfate, during which time the legumin mRNA levels returned almost to normal. Two recovery situations were studied: cultured seeds, with sulfate added to the medium, and seeds attached to the intact plant, with sulfate added to the roots. In both situations the levels of cysteine, glutathione, and methionine rose rapidly, glutathione exhibiting an initial lag. In attached but not cultured seeds methionine markedly overshot the level normally found in sulfur-sufficient seeds. In the cultured seed S-adenosylmethionine (AdoMet), but not S-methylmethionine, showed a sustained rise; in the attached seed the changes were slight. The composition of the free amino acid pool did not change substantially in either recovery situation. In the cultured seed the large rise in AdoMet level occurred equally in nonrecovering seeds. It was accompanied by 6-fold and 10-fold increases in γ-aminobutyrate and alanine, respectively. These effects are attributed to wounding resulting from excision of the seed. ³⁵S-labeling experiments showed that there was no significant accumulation of label in unidentified sulfur-containing amino compounds in either recovery situation. It was concluded from these results and those of other workers that, at the present level of knowledge, the most probable candidate for a `signal' compound, eliciting recovery of legumin mRNA level in response to sulfur-feeding, is cysteine.     

Post ovulatory changes in the concentration of prostaglandins in rabbit Graafian follicles

In previous studies we have demonstrated that prior to hCG induced ovulation the levels of PGF and PGE in rabbit Graafian follicles increase markedly as ovulation approaches. We have now extended the study to include follicles obtained from animals at ovulation time and up to 48 hours after hCG injection. We have found that PGF reaches a maximum in ovulated follicles at the time of ovulation and then quickly decreases, whereas PGE continues to rise for several hours and then declines. The increase in both prostaglandins is limited to the follicles that actually ovulate. These data further document the proposed role for prostaglandins in the ovulatory process.     

Studies on the Biochemistry and Fine Structure of Silica Shell Formation in Diatoms. Chemical Composition of Navicula pelliculosa during Silicon-Starvation Synchrony

Changes are reported in total cellular organic carbon, nucleic acids, proteins, carbohydrates, lipids and chlorophylls during the course of silicon-starvation synchrony of Navicula pelliculosa. All constituents increased at the same rate, relative to cell number, for 30 hours of exponential growth during which silicon was depleted from the medium. Increase in cell number then stopped, but net synthesis of most components continued for a further 5 to 7 hours before ceasing. Deoxyribonucleic acids and lipids accumulated throughout the 14 hour silicon-starvation period. When silicon was resupplied, lipid synthesis ceased and organic carbon and carbohydrates decreased slightly. Net synthesis remained low during the 4 hour silicon uptake period but was resumed at higher rates as cell number began to rise. In cultures transferred to the dark 1 hour prior to readdition of silicon, total carbon, carbohydrates, and lipids decreased markedly during silicon uptake and cell separation. This was due in part to conversion of protein which maintained the protein level of the dark cells close to that of cells kept in the light. Mechanisms by which silicon starvation and reintroduction of silicon might affect rates of cellular synthesis are discussed.     

The importance of sulfate reduction associated with Ulva lactuca thalli during decomposition: a mesocosm experiment

The decay of the macroalga Ulva lactuca was followed for 54 days in a controlled laboratory experiment. The experiment focused on the activity of sulfate reducers in different compartments (water, thalli and sediment) of the experimental system. In addition to sulfate reduction, the concentrations of sulfide, carbon dioxide, sulfate, carboxylic acids and pH were determined at regular intervals. Interestingly, 90% of the system-integrated sulfate reduction was carried out in the water column by thallus-associated sulfate reducers. The sediment accounted for about 10% of the integrated sulfate reduction activity, while sulfate reduction carried out by free-living sulfate reducers was insignificant and represented less than 1% of total sulfate reduction. Sulfate reduction rates in the water column were below the detection limit at the beginning of the experiment and were detected after 1 week of incubation. Sulfate reduction rates associated with thalli were measurable immediately after the experiment was started and increased very rapidly, reaching extremely high rates after 1 week of incubation. Sediment sulfate reduction rates had increased to twice the initial value by day 30 after which they remained constant. Thallus-associated sulfate reduction rates (SRR) were of the same level in all layers of the algal mat throughout the experiment. Our results indicate that sulfate-reducing bacteria were present on the thalli when the experiment was initiated and that the water column colonization by sulfate-reducing bacteria from the sediment was less important. This would explain the rapid accumulation of hydrogen sulfide in the water column during macroalgal decay events in coastal marine environments.     

Mesentery capillary barrier in rats injected intravascularly with ascitic Zajdela hepatoma. III. Effect of serotonin and histamine on the extravasation of the tumor]

The addition of serotonin or of histamin with tumoral cells of ascitic Zajdela's hepatoma and their injection in aorta induce plain hemodynamic changes and increase the tumoral extravasation. So only cells blocked in thrombi are observed in blood vessels. Therefore, serotonin and histamin do facilitate tumoral cells extravasation, allowing so a better metastatic diffusion in this experimental pattern.     

We age because we grow

Why do we age? Since ageing is a near-universal feature of complex organisms, a convincing theory must provide a robust evolutionary explanation for its ubiquity. This theory should be compatible with the physiological evidence that ageing is largely due to deterioration, which is, in principle, reversible through repair. Moreover, this theory should also explain why natural selection has favoured organisms that first improve with age (mortality rates decrease) and then deteriorate with age (mortality rates rise). We present a candidate for such a theory of life history, applied initially to a species with determinate growth. The model features both the quantity and the quality of somatic capital, where it is optimal to initially build up quantity, but to allow quality to deteriorate. The main theoretical result of the paper is that a life history where mortality decreases early in life and then increases late in life is evolutionarily optimal. In order to apply the model to humans, in particular, we include a budget constraint to allow intergenerational transfers. The resultant theory then accounts for all our basic demographic characteristics, including menopause with extended survival after reproduction has ceased.     

力竭性游泳对大鼠睾丸金属结合蛋白的诱导及其与睾酮和锌的关系

本研究通过观察大鼠力竭性游泳后睾丸金属结合蛋白（ＴＭＢＰ）、睾酮和锌含量的动态变化,探讨ＴＭＢＰ的被诱导性、诱导特点以及与睾酮合成和锌代谢的关系。结果显示：大鼠力竭性游泳后,ＴＭＢＰ呈一过性升高,峰值在游泳后６ｈ处,达安静时的１６倍;游后１２ｈ已降回原有水平。这表明ＴＭＢＰ可被力竭性游泳所诱导,半减期不到６ｈ。ＴＭＢＰ诱导性的发现对认识ＴＭＢＰ的功能具有重要的意义。大鼠睾丸睾酮在力竭性游泳后即刻急剧下降,以后逐渐恢复。此恢复过程伴有ＴＭＢＰ的升高。考虑睾酮合成中对锌的高度依赖性以及ＴＭＢＰ结合锌的功能,ＴＭＢＰ很可能在睾酮的合成中参与锌的摄取、转运和供给过程。大鼠ＴＭＢＰ在力竭性游泳后６ｈ处于高峰时,血清锌却处在低谷,这说明ＴＭＢＰ很可能从血清中摄取锌离子,参与应激后锌的再分配活动。     

Effects of rat bile infusion on renal function in rats.

The influence of rat bile infusion on renal function in rats and the possible role of bile-induced hemolysis in these effects were examined. The hemolytic action of rat bile and some bile salts were determined in vitro. After the i.v. infusion of rat bile (70 mg freeze-dried powder/2.55 ml) into pentobarbitone-anesthetized rats, the urine, sodium and potassium excretion rates were reduced more than half, which was due to the decrease of glomerular filtration rate and increase of tubular water and sodium reabsorption. A fall in blood pressure, a rise in hematocrit, and hemolysis were also found. Infusion of hemolysed (30 microliters RBC) solution produced by distilled water and then made isotonic caused a short-duration increase in renal excretion and glomerular filtration rate, and the blood pressure was unchanged. Infusion of a rat bile-hemolysed solution after removal of bile acids with cholestyramine increased renal excretions at first with reduction thereafter. Infusion of the rat bile-hemolysed solution treated with barium sulfate produced a renal response very similar to rat bile alone. It is proposed that two factors are involved in the renal response after bile infusion, namely bile acid-induced hemolysis producing diuresis with natriuresis, and bile acid-induced antidiuresis and antinatriuresis, possibly due to a direct renal effect.     

Chromatographic separation of vitamin D3 sulfate and vitamin D3.

This paper describes a simple chromatographic technique on Sephadex LH20 for the separation of vitamin D3 sulfate from free vitamin D3 and its metabolites. This technique has been used in the study of vitamin D3 sulfate metabolism in rats. Seven hours after injection of vitamin D3 sulfate (35S or 35S and 3H) only the peak of vitamin D sulfoconjugate was found in chromatographic elution of serum extracts.     

Effect of additives on mass transfer in turbine aeration

Mass transfer coefficients and interfacial areas were determined for the aeration of aqueous solutions in a turbine agitated vessel. The mass transfer coefficients measured for water without additive and for sodium chloride solutions matched very well to measurements in the literature for air bubbles of the same diameter in free rise. Thus the only effect of agitation was to determine the bubble size which then in turn set the coefficient. Two surface active agents were studied: sodium dodecyl sulfate and Dow Corning Antifoam C. The rate of mass transfer increased with the former additive but decreased with the latter; however, the mass transfer coefficient was the exact same function of bubble diameter in both cases and the different rates are attributed to the quite different effects on interfacial area.     

Development of Embryo and Fruit in Ipomoea batatas Lam

This paper deals with the development of the embryo and the formation of the fruit for lpomoea batatas Lam. based on the observation of its flower bud differentiation, megasporogenesis and the development of the female gametophyte, microsporogenesis and the development of the male gametophyte. The pollen grain germinated on the stigma about 10–30 min. after pollination. The pollen tube penetrated the transmitting tissue in the middle of the style between 30–60 min. after pollination. After 2 hours the tip of the pollen tube reached the micropyle. Double fertilization completed after 5 or 12 hours then the zygote and the endosperm nucleus formed. The first mitotic division of the endosperm nucleus takes place about 12 hours after pollination, earlier about 3 hours than the first division of the zygote, the latter gives rise to a terminal cell and a basal cell by a transverse division. The second division is transverse in the terminal cell, forming two cells. The basal cell divides longitudinally into two adjoining cells. The terminal cell becomes the proembryo with four cells, and at the same time, the basal cell becomes the suspensor with four cells after 41–52 hours. The proembryo gradually becomes globular, cordate and torpedo-shaped, respectively about 96–120, 144–156, 168-192 hours after pollination. The cotyledons of the embryo gradually prolongate 10 days after pollination. The embryo almost completes its development within 21–30 days after pollination. he fruit is a capsule. The ovary gradually swells 3–4 days after pollination, then forms fruit, which ripens about 21–30 days after pollination, 2R.=4–8 mm. A fruit contains 1–4 seeds. 7,000 fruits were analysed in 1983, the results are as follows: 64.6% of then with only one seed in a capsule, 31.8% two seeds, 5.48% three seeds and 0.1% four seeds. The seeds are small, 2R. from 3.84 mm to 2.84 mm. The shape and the weight of the seeds are different from each other because of difference in number of seeds within a capsule.     

Effect of maternal deprivation on polyamine metabolism in preweanling rat brain and heart

Ornithine Decarboxylase (ODC) the first and probably rate-limiting step in polyamine biosynthesis, is usually elevated in tissues with high rates of growth or protein synthesis and in preweanling rat brain is altered by hormones thought to play a role in stress such as thyroxine and cortisol. Maternal deprivation stress was examined for its effect on preweanling rat brain ODC activity. Ten day old rat pups were removed from the maternal cage, then alternately returned to the mother or placed in a warm environment after the method of Hall. Pups taken from the mother for as little as 1 hour show a significant decline in their whole brian ODC activity. The effect peaked at 2–4 hours of deprivation, at which time the brain ODC activity was 60% below that of the equally handled littermate controls. Two hours of deprivation produced a similar effect throughout preweanling development. The effect occurred in all brain regions and also in heart. Return to mother reversed rapidly the deprivation-induced ODC decline, with ODC activity overshooting to 300% of control 2 hours after return, then declining to baseline by 4 hours. Putrescine, the immediate product of the ODC reaction, declined 15% one hour after deprivation, and 50% in brain and heart after 15 hours. These data demonstrate that maternal deprivation alters polyamine metabolism in preweanling rat brain and heart.