The presence of cellular metabolites in milk

Cellular metabolites are present in goats' milk. The concentrations of UDPgalactose and some nucleotides were higher in milk than in mammary tissue. Other metabolites were present in milk at similar concentrations to those found in the mammary gland. It is proposed that the concentrations of these metabolites in milk reflect their Golgi-vesicular and cytosolic concentrations.     

Level and distribution of progesterone in bovine milk in relation to storage in the mammary gland.

The study investigated the effect of the place of storage of milk in the mammary gland on progesterone concentrations in whole milk, skim milk and milk fat. Skim milk, milk fat and whole milk progesterone concentrations were lower (P < 0.05) in milk fractions obtained from the cisternal part of the mammary gland compared to those in the milk fractions from the alveoli. Mean milk fat concentrations did not mirror the changes in the mean skim milk, milk fat and whole milk progesterone concentrations. After administration of oxytocin, milk fat concentrations rose significantly (P < 0.01). At the same time, skim milk and milk fat progesterone concentrations remained unchanged (P > 0.05), compared to those in the milk fractions of alveolar origin, obtained before oxytocin administration. Skim milk and whole milk progesterone concentrations were higher (P < 0.01) in composite milk and in milk samples collected 1 h after milking, compared to concentrations in the milk samples collected before morning milking and at 3, 5, 7 and 9 h after milking. The results suggest that defatted milk, milk fat and whole milk progesterone concentrations were affected by the place of storage of the milk in the mammary gland, and that this effect is independent of milk fat content. Time of milk sampling, not the milk fat concentration, in relation to time of milking, was a critical factor in determining skim milk, milk fat and whole milk progesterone. The study also revealed that the concentrations of the other milk components, somatic cell count, lactose and protein were affected by the place of storage of milk in the mammary gland.     

Evidence for a major role of inhibin in the feedback control of FSH in the male rat

Adult rats (16-18/group) received a single intratesticular injection of 25, 100 or 400 microliters glycerol solution (7:3 in distilled water, v/v). Half of the rats in each group were given implants of testosterone, a testosterone-filled Silastic capsule (1.5 cm length) to provide serum values of testosterone within the normal range. After 1 week all animals were killed by decapitation. Serum concentrations of gonadotrophins, testosterone and immunoactive inhibin as well as testicular concentrations of testosterone and bioactive inhibin were determined. Testicular histology was studied in Paraplast-embedded tissue stained with PAS and haematoxylin-eosin. Glycerol treatment caused a dose-dependent ablation of spermatogenesis in a distinct area around the site of injection. Serum concentrations of FSH increased proportionally with increasing spermatogenic damage while serum LH and testosterone remained unaltered except with the highest glycerol dose. The rise in serum FSH was significantly correlated with serum (r = -0.70, P less than 0.001) and testicular (r = -0.66, P less than 0.001) concentrations of inhibin. A less pronounced correlation was found between LH and serum inhibin (r = 0.48). No correlation was found between the concentrations of LH and testicular inhibin or between serum concentrations of FSH and serum testosterone in the 25 and 100 microliters groups. Maintenance of low to normal serum testosterone concentrations by means of Silastic implants blocked the elevation of FSH in glycerol-treated animals but failed to affect significantly serum FSH in untreated rats. In all testosterone treated rats testicular inhibin concentrations were markedly reduced in the presence of lowered concentrations (7-14%) of testicular testosterone and unaltered serum FSH concentrations.     

Growth,water and nutrient status of plants in relation to patterns of variations in concentrations of dry matter and nutrient elements in base-to-top leaves

Summary Patterns of variations in dry matter concentrations in tomato plants reflected production and translocation of dry matter, implying the possibility of controlling and regulating growth and development of plants by use of dry matter concentration as a useful parameter.Dry matter concentrations, analogous to nutrient concentrations, varied depending on growth conditions, and on type, age and position of plant organs.Interpretation of patterns of variations in contents and concentrations of leaf dry matter in plants, grown under widely different conditions, agreed with the source/sink hypothesis.High water applications were associated with high dry matter concentrations in upper leaves of young pot plants with low sink capacity and with low dry matter concentrations in leaves of older, trough-grown plants with high sink capacity.Accumulation of dry matter in upper leaves of plants is suggested to be associated with development of secondary sinks and, accumulation of dry matter in lateral shoots is considered as a possible explanation of apical dominance.Water regime and transpiration influenced distribution of contents of dry and fresh matter and of absorbed nutrient elements. Redistribution was influenced by water regime.The term, distribution is in the following used in connection with not only absolute values (contents) but also relative values (concentrations).     

Differential distribution of leaf chemistry in eucalypt seedlings due to variation in whole-plant nutrient availability

We investigated the effects of whole-plant nutrient-availability on the degree of distribution of some plant primary and secondary (nitrogen, fibre, flavonols, gallotannins and cineole) chemicals across young, mature and old leaves of seedlings of Eucalyptus nitens. Four treatments that ranged from low to high nutrient-application rates resulted in mean whole-plant foliar concentrations of 0.63%, 0.85%, 1.11% and 1.82% nitrogen dry matter (N%DM) for treatments A, B, C and D, respectively. Within-plant distribution (across the leaf age profile of young, mature and old leaves within a eucalypt seedling) of N%DM ranged from zero in treatment A to a wide range of distribution in treatment D (low N%DM concentrations in old leaves to high N%DM concentrations in young leaves). Similarly, the distribution of fibre ranged from zero in treatment A to a wide range of distribution in treatment D, but with high concentrations in old leaves and low concentrations in young leaves. In contrast, flavonols (weakly) and gallotannins had a wide range of distribution in treatment A (low concentrations in old leaves to high concentrations in young leaves) but were little or not distributed in the other treatments. Again in contrast, cineole was strongly distributed between old and young leaves (low concentrations in old leaves to high concentrations in young leaves) across all treatments while concentrations in mature leaves reflected one or other leaf age depending on treatment. Protein precipitable phenols in treatments A, B and C were high in young, and low in old leaves; whereas in treatment D they were low and similar between leaves of different ages.     

Comparison of Concentrations of Selected Metals and Organics in Fish Tissue and Sediment in the Grand River,Ohio, and the Southern Lake Erie Drainage Basin

The purpose of this paper is to develop a database of fish tissue and sediment concentrations of selected chemicals in the southern Lake Erie drainage basin, to compare contaminant concentrations in fish tissue and sediment collected from the Grand River, Ohio, in the vicinity of a former soda ash and chromate plant with that for other waterbodies in the drainage basin, and to evaluate the potential human health risks posed by these chemicals, with special focus on chromium. The results of this study indicate that chemical concentrations in fish tissue and sediment from the Grand River are generally lower than that of other waterbodies in the southern Lake Erie drainage basin. Although arsenic and beryllium concentrations in Grand River sediment are above their respective human health-based concentrations, these concentrations are comparable with local and regional background and are not expected to pose a significant incremental risk to human health. In addition, sediment concentrations do not exceed ecological screening criteria. Although PCB and several pesticides were found to have concentrations in fish tissue from the Grand River in excess of human health based concentrations, these concentrations are among the lowest found in waterbodies in the southern Lake Erie drainage basin.     

Impact of inspired substance concentrations on the results of breath analysis in mechanically ventilated patients.

A well-defined relationship has to exist between substance concentrations in blood and in breath if blood-borne volatile organic compounds (VOCs) are to be used as breath markers of disease or health. In this study, the impact of inspired substances on this relationship was investigated systematically. VOCs were determined in inspired and expired air and in arterial and mixed venous blood of 46 mechanically ventilated patients by means of SPME, GC/MS. Mean inspired concentrations were 25% of expired concentrations for pentane, 7.5% for acetone, 0.7% for isoprene and 0.4% for isoflurane. Only if inspired concentrations were <5% did substance disappearance rates from blood and exhalation rates correlate well. Exhaled substance concentrations depended on venous and inspired concentrations. Patients with sepsis had higher n-pentane and lower acetone concentrations in mixed venous blood than patients without sepsis (2.27 (0.37-8.70) versus 0.65 (0.33-1.48) nmol L-1 and 69 (22-99) versus 18 (6.7-56) micromol L-1). n-Pentane and acetone concentrations in breath showed no differences between the patient groups, regardless whether or not expired concentrations were corrected for inspired concentrations. In mechanically ventilated patients, concentration profiles of volatile substances in breath may considerably deviate from profiles in blood depending on the relative amount of inspired concentrations. A simple correction for inspired substance concentrations was not possible. Hence, substances having inspired concentrations>5% of expired concentrations should not be used as breath markers in these patients without knowledge of concentrations in blood and breath.     

Sugar Accumulation in Barley and Rice Grown in Solutions with low Concentrations of Oxygen

Barley and rice, at the early tillering stage, were grown inaerated nutrient solutions (> 7 mg O₂ l^–1) and transferredto solutions of low O₂ concentrations (< 0.5 mg l ^–1). For barley, low O₂ concentrations during the first 5 days severelyinhibited growth of seminal roots had less effect on nodal roots,and did not reduce shoot growth. Longer exposure to low O₂ concentrationsreduced shoot as well as root growth. Sugar concentrations inroots and shoots increased within 7 h after transfer of plantsto low O₂ concentrations. After 5 days at low O₂ concentrationssugar concentrations were very high in fast growing nodal rootsand in shoots, as well as in the slower growing seminal roots. In rice, low O₂ concentrations increased sugar levels of rootsduring summer, but not during winter. In summer, the highersugar levels at low O₂ concentrations persisted throughout adiurnal cycle. In root apices, sugar concentrations were increasedby low O₂ concentrations, even though the experiment was donein winter and the bulk of the root system showed no differencein sugar levels. The data indicate that sugar accumulation, at low O₂ concentrations,is caused by reduced growth and also that even apices of rootsgrown at low O₂ concentrations have sufficient substrates forrespiration. Hordeum vulgare L, barley, Oryza sativa L, rice, sugar accumulation, oxygen concentration     

Distribution of cadmium and lead in a stream ecosystem

Cadmium and lead were detected in all components of the stream that were examined. Cadmium was present in similar concentrations in both fishes and sediments. Aquatic insects, however, exhibited higher concentrations of cadmium than did sediments. Lead concentrations in sediments and aquatic insects were similar, but higher than concentrations in fishes. Snails contained the highest level of lead and had noticeably greater amounts of the metal than did aquatic insects. In general, concentrations of both metals increased successively from water to fish to sediments to aquatic invertebrates.     

Expression of endogenous proteins in maize hybrids in a multi-location field trial in India

Genetically modified (GM) crops undergo large scale multi-location field trials to characterize agronomics, composition, and the concentration of newly expressed protein(s) [herein referred to as transgenic protein(s)]. The concentration of transgenic proteins in different plant tissues and across the developmental stages of the plant is considered in the safety assessment of GM crops. Reference or housekeeping proteins are expected to maintain a relatively stable expression pattern in healthy plants given their role in cellular functions. Understanding the effects of genotype, growth stage and location on the concentration of endogenous housekeeping proteins may provide insight into the contribution these factors could have on transgenic protein concentrations in GM crops. The concentrations of three endogenous proteins (actin, elongation factor 1-alpha, and glyceraldehyde 3-phosphate dehydrogenase) were measured in several different maize hybrids grown across multiple field locations over 2 years. Leaf samples were collected from healthy plants at three developmental stages across the growing seasons, and protein concentrations were quantified by indirect enzyme-linked immunosorbent assay (ELISA) for each protein. In general, the concentrations of these three endogenous proteins were relatively consistent across hybrid backgrounds, when compared within one growth stage and location (2–26%CV), whereas the concentrations of proteins in the same hybrid and growth stage across different locations were more variable (12–64%CV). In general, the protein concentrations in 2013 and 2014 show similar trends in variability. Some degree of variability in protein concentrations should be expected for both transgenic and endogenous plant-expressed proteins. In the case of GM crops, the potential variation in protein concentrations due to location effects is captured in the current model of multi-location field testing.     

Effect of dextran-coated charcoal on radioimmunoassays of unconjugated estriol in serum

Lipid interference in the radioimmunoassay of steroids can cause an apparent variation in post-prandial serum concentrations of unconjugated estriol. The effects of increased concentrations of dextran-coated charcoal (15--60 g/l) in the radioimmunoassay of estriol standards with and without triglycerides were studied. All concentrations of dextran-coated charcoal used in this study eliminated the previously observed effects of estriol-lipid partitioning. When we used similar concentrations of dextran-coated charcoal, we found that serum cortisol levels in pregnant women declined significantly during the day (P less than 0.001), but no significant variation in estriol concentrations was observed. These results indicate that the previously reported diurnal variation in serum unconjugated estriol concentrations attributed to steroid-lipid partitioning can be eliminated by increasing the concentration of dextran-coated charcoal in assays using this method of separation.     

Thorough investigation of epileptic behavioral characterization of caffeine in adult zebrafishes in correlation with drug brain concentration

Our present research aimed to perform a detailed behavioral characterization of caffeine-induced seizure activity in zebrafish. Epileptic activity was observed by immersing individuals in different concentrations of caffeine solution at 250, 350, and 500 mg/l, respectively. Higher concentrations of caffeine rapidly induced intense behavioral activity resembling tonic seizures. Lower concentrations resulted in behavior that was less intense but sustained for longer periods. Significant attenuation of seizure severity was observed in zebrafish pretreated with the barbiturate phenobarbitone. Finally, brain caffeine levels were measured using HPLC-UV methodology in fish immersed in different concentrations of caffeine. Brain caffeine levels increased with higher concentrations of caffeine treatment; however, they were not significantly altered by pretreatment with phenobarbitone.     

Effects of GTP on cyclic AMP concentrations in intact Ehrlich ascites tumor cells.

Experiments were conducted to test the hypothesis that intracellular concentrations of guanosine triphosphate (GTP) regulate the activity and hormonal sensitivity of adenylate cyclase in intact cells. By appropriate treatments, the GTP concentrations of Ehrlich ascites tumor cells could be varied between 28% and 680% of control values. Cyclic AMP concentrations were measured before and after addition of epinephrine in cells containing this range of GTP concentratins. Basal cyclic AMP concentrations were unaffected by changes in GTP concentrations. In cells containing lowered concentrations of GTP, the cyclic AMP concentration following addition of epinephrine was half that in control cells. Elevation of GTP concentrations above normal and had no effect on cyclic AMP concentrations following epinephrine treatment.     

Phytotoxic effects of (+/-)-catechin in vitro, in soil, and in the field

Background

Exploring the residence time of allelochemicals released by plants into different soils, episodic exposure of plants to allelochemicals, and the effects of allelochemicals in the field has the potential to improve our understanding of interactions among plants.

Methodology/Principal Findings

We conducted experiments in India and the USA to understand the dynamics of soil concentrations and phytotoxicity of (±)-catechin, an allelopathic compound exuded from the roots of Centaurea maculosa, to other plants in vitro and in soil. Experiments with single and pulsed applications into soil were conducted in the field. Experimental application of (±)-catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations. Pulses replenished (±)-catechin levels in soils, but consistently at concentrations much lower than were applied, and even pulsed concentrations declined rapidly. Different natural soils varied substantially in the retention of (±)-catechin after application but consistent rapid decreases in concentrations over time suggested that applied experimental concentrations may overestimate concentrations necessary for phytotoxicity by over an order of magnitude. (±)-Catechin was not phytotoxic to Bambusa arundinacea in natural Indian soil in a single pulse, but soil concentrations at the time of planting seeds were either undetectable or very low. However, a single dose of (±)-catechin suppressed the growth of bamboo in sand, in soil mixed with organic matter, and Koeleria macrantha in soils from Montana and Romania, and in field applications at 40 µg l⁻¹. Multiple pulses of (±)-catechin were inhibitory at very low concentrations in Indian soil.

Conclusions/Significance

Our results demonstrate that (±)-catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied at low concentrations in the field. However, there is substantial conditionality in the effects of the allelochemical.     

Changes in Pool Sizes of Free Amino Acids and Amides in Leaves and Plastids of Zea mays during Leaf Development

The concentrations of free amino acids and amides within isolated maize (Zea mays L.) plastids were determined and compared with concentrations in the leaf tissue. The concentrations were different for each individual amino acid and varied between 1 and 10 millimolar. At five different developmental stages concentrations in the plastids were greater than those in the intact leaf tissue. During development, from the proplastid stage to the mature chloroplast, the amount of each amino acid per plastid remained relatively constant, but there were decreases in concentrations of plastid amino acids resulting from the developmental increase in plastid volume. In proplastids, the free amino acids were present in greater concentrations than those previously found to inhibit partially amino acid-synthesizing enzymes located in chloroplasts. In the chloroplasts, the molarities of the free amino acids were within the range known to inhibit amino acid-synthesizing enzymes.     

不同生境下骆驼刺与花花柴生态化学计量学特征的比较

以塔克拉玛干沙漠南缘典型荒漠豆科植物骆驼刺(Alhagi sparsifolia)和菊科植物花花柴(Karelinia caspia)为对象,研究单一骆驼刺种群(LTC)、单一花花柴种群(HHC)及骆驼刺-花花柴群落(GSQL)中植物及土壤中碳(C)、氮(N)、磷(P)、钾(K)等养分的生态化学计量学特征。结果表明:骆驼刺-花花柴群落中土壤有效N(AN)、有效K(AK)含量及N∶P、N∶K显著高于单一花花柴种群;骆驼刺-花花柴群落中花花柴叶片的全N含量显著高于单一花花柴种群,骆驼刺-花花柴群落中骆驼刺叶片的全P含量显著高于单一骆驼刺种群。相关性分析显示:不同生境土壤的AK含量与N∶P及AN含量呈显著正相关,而与SOC呈负相关;不同生境下叶片中的全K含量与SOC、全N、全P含量呈显著正相关,叶片中的全N含量与SOC、全P亦呈显著正相关,而N∶P与SOC、全P含量呈显著负相关;土壤中SOC含量与叶片中全P、全K含量呈正相关,而与N∶K呈负相关;土壤有效N含量与叶片N∶K呈正相关,而与叶片4种元素含量均呈显著负相关;土壤有效K含量与叶片中4种元素含量均呈显著负相关,而与叶片N∶K呈正相关;土壤N∶P、N∶K则分别与叶中全C、全P、全K呈显著负相关。综合分析认为:相较于单一种群,骆驼刺与花花柴的群落能够在一定程度上提高土壤养分,改善植物的营养状况,显示出豆科植物骆驼刺在群落演替中重要作用。     

Presence of acute phase changes in zinc, iron, and copper metabolism in turkey embryos

Acute phase changes in trace mineral metabolism were examined in turkey embryos. An endotoxin injection resulted in increased concentrations of serum copper and liver zinc and decreased concentrations of serum zinc in embryos incubated either in ovo or ex ovo. Changes in zinc and copper metabolism occurred when endotoxin either was injected intramuscularly, into the amnionic fluid, or administered onto the chorioallantoic membrane. Unlike poults, embryos did not respond to an inflammatory challenge with decreased serum iron concentrations. Acute phase changes in embryo serum zinc and copper as well as liver zinc concentrations were similar to those in poults. Increased liver zinc concentrations were associated with increased zinc in metallothionein (MT). An injection of a crude interleukin 1 preparation into embryos resulted in similar increases in hepatic zinc and MT concentrations as an endotoxin injection, suggesting a role for this cytokine in mediating the acute phase changes in embryonic zinc metabolism.     

Impact of inspired substance concentrations on the results of breath analysis in mechanically ventilated patients

Abstract

A well-defined relationship has to exist between substance concentrations in blood and in breath if blood-borne volatile organic compounds (VOCs) are to be used as breath markers of disease or health. In this study, the impact of inspired substances on this relationship was investigated systematically. VOCs were determined in inspired and expired air and in arterial and mixed venous blood of 46 mechanically ventilated patients by means of SPME, GC/MS. Mean inspired concentrations were 25% of expired concentrations for pentane, 7.5% for acetone, 0.7% for isoprene and 0.4% for isoflurane. Only if inspired concentrations were <5% did substance disappearance rates from blood and exhalation rates correlate well. Exhaled substance concentrations depended on venous and inspired concentrations. Patients with sepsis had higher n-pentane and lower acetone concentrations in mixed venous blood than patients without sepsis (2.27 (0.37–8.70) versus 0.65 (0.33–1.48) nmol L^?1 and 69 (22–99) versus 18 (6.7–56) µmol L^?1). n-Pentane and acetone concentrations in breath showed no differences between the patient groups, regardless whether or not expired concentrations were corrected for inspired concentrations. In mechanically ventilated patients, concentration profiles of volatile substances in breath may considerably deviate from profiles in blood depending on the relative amount of inspired concentrations. A simple correction for inspired substance concentrations was not possible. Hence, substances having inspired concentrations >5% of expired concentrations should not be used as breath markers in these patients without knowledge of concentrations in blood and breath.     

Characterization of maize lines differing in leaf abscisic Acid content in the field. 1 abscisic Acid physiology

The inbred maize lines Poljl7 and F-2 have previously been shown to differ by up to three-fold in leaf abscisic acid (ABA) concentration in the field. Lines from the cross Poljl7 × F-2 differing in leaf ABA concentrations, and the parents, were studied in the field to characterize the differences amongst the lines in ABA concentrations during the season, during the day and in different parts of the plants. The water status of the plants was measured and leaves were heat girdled to get information on possible causes for the genetic variation amongst the lines in ABA concentration. Leaf ABA concentrations of the high-AB A lines increased markedly and consistently from flowering time onwards, whereas leaf ABA concentrations of the low-ABA lines gradually fell after flowering. Leaf water potentials of high-ABA and low-ABA lines were similar during this time. Leaf ABA concentrations varied little during the day, and heat girdling caused a rise in ABA concentrations, which was similar in both high-ABA and low-ABA lines, only after girdling for at least 4 h. ABA concentrations were highest in the leaves and it was only in the leaves and developing kernels that substantial differences in ABA concentrations were found between the high-ABA and low-ABA classes. Although aerial brace roots also had high ABA concentrations, other roots and stem internodes had ABA concentrations which were consistently low and the same for both ABA classes. Differences between the ABA classes were unlikely to be due to differences in leaf water status or in ABA export from the leaves. Other possible explanations for the genotypic differences in leaf ABA concentrations are discussed.     

Changes in serum FSH concentrations in the pig during development

Serum FSH concentrations were measured in fetal and prepubertal pigs between 40 days postcoitum and 25 weeks after birth. In addition, serum FSH was estimated in prepubertal, unilaterally cryptorchid, freemartin and castrated pigs. The average serum FSH concentrations in male and female fetuses was low (less than 2 ng/ml) until 80 days p.c. During the remaining fetal period, concentrations in females were elevated (7.9 +/- 0.4 ng/ml) and remained fairly constant after birth (16.3 +/- 0.8 ng/ml). In the male, serum FSH concentrations gradually rose to 22.5 +/- 5.5 ng/ml during the first 3 weeks after birth and declined thereafter. The changes in FSH concentrations in male pigs are reflected in gonadal-development. In contrast, in fetal and prepubertal females, ovarian development seems not to be influenced by changes in serum FSH concentrations. Unilateral cryptorchidism did not affect serum FSH concentrations. After castration, however, concentrations rose significantly. In freemartin pigs concentrations were similar to those in female pigs.