Increase In Relative Percentage Research Articles

PAH-profiles in sediment cores from the Baltic Sea

To document the historical input the PAH-profiles of sediment cores in two different basins of the Baltic Sea, the Gotland Basin (GB) and Arkona Basin (AB), were analysed by means of GC-MS. 35 PAHs were quantified in all samples, and additionally, several marker PAHs, like Cyclopenta[cd]phenanthrene (CCP) for combustion processes and retene for terrigenous input, were quantified in selected samples. The preindustrial sediments (older than 200–250 years) in the GB core illustrate concentrations <100 ng PAH 35 g −1 d.w. Calculated PAH-ratios indicated combustion processes as the main sources for both basins. The Perylene concentrations within the sediment cores decrease with increasing depth, along with an increase in relative percentage, indicating slow diagenetic processes. The preservation and enrichment of the introduced PAHs was more pronounced in the GB core.

Capture ELISA and flow cytometry methods for toxicologic assessment following immunization and cyclophosphamide challenges in beagles

The purpose of this subacute 22-day study was to evaluate methods for canine circulating immunoglobulins (IgM, IgG, and IgE) and select B- and T-lymphocyte populations (CD4-helpers, CD8-suppressors, pan-T and pan-B) for immunotoxicity testing using an organ system (concordance) approach. The challenge substance for immunoglobulin testing was repeated immunization with six-way distemper vaccination (DHLAPP), while the challenge substance for leukocyte subpopulations was treatment with cyclophosphamide. Immunoglobulin measurements were made by capture enzyme-linked immunosorbent assay (ELISA), and leukocyte immunophenotyping by fluorescein isothiocyanate/phycoerythrin conjugation (flow cytometry). A battery of parameters that would be used in a typical regulatory study were taken to aid interpretation of the data generated by these methods. Body weights, food consumption, clinical observations, complete clinical chemistry and urinalysis measurements were taken. Gross pathology and micropathology of sternal bone marrow, spleen, mesenteric and retropharyngeal lymph nodes, thymus, liver and kidney were completed. The ELISA method demonstrated acceptable intra-assay reproducibility for IgM, IgG and IgE, with values in good agreement as reported for radial immunodiffusion. The immunologic challenge demonstrated a biological trend of an increase in IgM that preceded an increase in IgG with no discernible trend in IgE response, and no abnormalities in lymphocyte subpopulations. Principle flow cytometry findings related to cyclophosphamide were that the relative percent of B cells decreased dramatically and progressively after compound administration; being statistically decreased in males on day 22 compared with day −5. The relative percent CD4 and CD8 contribution increased, but the CD4/CD8 ratio remained relatively unchanged as total white blood cells decreased progressively. The increase in relative percent CD4 (males only) was statistically significant according to a two-sample t-test on days 17, 20 and 22 when compared with the pre-treatment day −5. There was a relative percent increase in CD5-panT, but absolute numbers were dramatically decreased. We conclude that an organ system approach to assessment of the immune system which incorporates humoral antibody, enumeration of lymphocyte populations and pathologic evaluation of the lymphoreticular organs assists in the interpretation of an adverse toxicological response. The ELISA method for measurement of Igs detected the expected levels of IgG, IgM and IgE due to repeated vaccinations and to cyclophosphamide treatment. The flow cytometry method was acceptable for measuring select canine lymphocyte populations and detecting the expected decrease in B cells due to cyclophosphamide treatment. Both methods may be added to a testing battery for assessing immunotoxicity in canine regulatory studies.

Effects of selective type I and II adrenal steroid agonists on immune cell distribution.

Adrenal steroids exert their effects through two distinct adrenal steroid receptor subtypes; the high affinity type I, or mineralocorticoid, receptor and the lower affinity type II, or glucocorticoid, receptor. Adrenal steroids have well known effects on immune cell distribution, and although both type I and II receptors are expressed in immune cells and tissues, few data exist on the relative effects mediated through these two receptor subtypes. Accordingly, we administered selective type I and II adrenal steroid receptor agonists to young adult male Sprague-Dawley rats for 7 days and then measured immune cell distribution in the peripheral blood and spleen. Results were compared with those of similar studies using the naturally occurring glucocorticoid of the rat, corticosterone, which binds both type I and II receptors. The majority of the well characterized effects of adrenal steroids on peripheral blood immune cells (increased neutrophils and decreased lymphocytes and monocytes) were reproduced by the type II receptor agonist, RU28362. RU28362 decreased the numbers of all lymphocyte subsets [T-cells, B-cells, and natural killer (NK) cells] to very low absolute levels. The largest relative decrease (i.e. in percentage) was seen in B-cells, whereas NK cells exhibited the least relative decrease and actually showed a 2-fold increase in relative percentage during RU28362 treatment. Similar to RU28362, the type I receptor agonist, aldosterone, significantly reduced the number of lymphocytes and monocytes. In contrast to RU28362, however, aldosterone significantly decreased the number of neutrophils. Moreover, aldosterone decreased the number of T-helper cells and NK cells, while having no effect on the number of B-cells or T-suppressor/cytotoxic cells. Corticosterone at physiologically relevant concentrations had potent effects on immune cell distribution, which were indistinguishable from those of the type II receptor agonist, RU28362. Taken together, these results indicate that effects of adrenal steroids on immune cell distribution are dependent on the receptor subtype involved as well as the specific cell type targeted. These factors allow for varied and complex effects of adrenal steroids on the immune system under physiological conditions.

Somatotopic mapping of the primary motor cortex in humans: activation studies with cerebral blood flow and positron emission tomography

1. The somatotopic representation of the human primary motor cortex was examined noninvasively with estimates of cerebral blood flow (CBF) obtained with positron emission tomography. Twelve normal subjects performed a motor tracking task with the arm, first finger, tongue, and great toe commensurate with the bolus injection of radioactive H215O. Images of the relative percent increase of blood flow, compared with control studies, demonstrated reproducible foci of CBF increases in the motor cortex in every subject. Each motor task could be localized to a predictable site on a coronal section containing the precentral gyrus. 2. In reproducibility experiments of repeated measures, it was determined that two foci of activation in the primary motor cortex could be discriminated with a 95% confidence if they were separated by 5.4 mm. 3. In five subjects with matched magnetic resonance imaging studies, the sites of activation were variable with respect to surface anatomy and could be found at the depth of sulci or the surface of gyri. The findings were similar to previously reported electrophysiological studies using direct cortical stimulation. 4. The method may be applied to the in vivo functional mapping of the primary motor cortex in patients with cerebral disorders.

Explanatory style and cell-mediated immunity in elderly men and women.

Correlated pessimistic explanatory style--the belief that negative events are caused by internal, stable, and global factors--with lowered immunocompetence in a sample of 26 older adults. Two measures of cell-mediated immunity--T-helper cell/T-suppressor cell ratio and T-lymphocyte response to mitogen challenge--were lower in individuals with a pessimistic style, controlling for the influence of current health, depression, medication, recent weight change, sleep, and alcohol use. A relative increase in the percentage of T-suppressor cells seemed to underlie this immunosuppression. Although the mechanism by which explanatory style might influence immune function remains unknown, we speculate that a pessimistic style might be an important psychological risk factor--at least among older people--in the early course of certain immune-mediated diseases.

Advantages of total lipid hydrogenation prior to lipid class determination on chromarods-SIII.

The changes in detector responses of lipid classes for standards and natural lipid samples after hydrogenation were investigated with the TLC/FID Iatroscan system using Chromarods-SIII (Newman-Howells Associates, Ltd., Midwales, U.K.). Samples included lipids of human plasma and erythrocytes, egg lipids, a fish oil concentrate and triacylglycerols of sea scallop, as well as standards (mono-, di- and triacylglycerols, phosphatidylcholines, phosphatidylethanolamines, lysophosphatidylcholines, free fatty acid, and sterol). The duration of hydrogenation was increased from 45 min to 90 min for some samples to bring hydrogenation to completion. Since the detector response of a lipid class is known to depend on its relative position on the Chromarod, different solvent systems which would vary the migration rate were investigated. The increases in response after hydrogenation, given as relative percent increase (RI), were significant for all compounds examined (p<0.05), and ranged from 7 to 45%. Among the triacylglycerols, the fish oil and the sea scallop triacylglycerols with wide ranges of fatty acid composition had the highest RI while the other lipid classes did not differ from each other. Differences in the solvent systems did not affect the RI except for fish oil triacylglycerols. The precision of peak area measurements was usually better after hydrogenation. The combination of greater sample stability, greater response, improved resolution, and simpler choice of standards make hydrogenation a significant advance in TLC/FID quantification.

Pericardial Effects on Diastolic Ventricular Interaction during Development

The effects of the pericardium on myocardial diastolic ventricular interaction during early development were determined in vitro using hearts excised from eight preterm (109 +/- 0.106 SE d gestation; term = 147 d) and eight newborn (2.3 +/- 0.30 SE d postnatal age) lambs. The lamb hearts were excised with the pericardium intact and immersed in a cold cardioplegic solution. Subsequently, very compliant balloon catheters were inserted into the right and left ventricles retrograde through the pulmonary artery and aorta respectively. Before and after the removal of the pericardium, the changes in left ventricular pressure or volume caused by increasing right ventricular pressure or volume were measured. Computerized analysis of the pressure and volume recordings yielded pressure and volume transfer functions that quantified ventricular interaction. The pressure transfer functions (left ventricular pressure/right ventricular pressure) both with and without the pericardium intact were 0.297 +/- 0.010 SE and 0.140 +/- 0.005 SE, respectively, for the preterms and 0.650 +/- 0.033 SE and 0.301 +/- 0.031 SE for the newborns. The volume transfer functions (left ventricular volume/right ventricular volume) with and without the pericardium were 0.320 +/- 0.04 SE and 0.150 +/- 0.024 SE, respectively, for the preterm and 0.514 +/- 0.052 SE and 0.233 +/- 0.027 SE for the newborns. These data demonstrate that 1) the pericardium increases ventricular interaction in both preterm and newborn lambs and 2) the relative percentage increase is similar for both age groups and not age dependent. Furthermore, these findings suggest that the increase in ventricular interaction due to the presence of the pericardium is mediated by the relative compliances of the free walls, septum, and pericardium.

Effect of rate and method of phosphate placement on productivity of durum wheat in mediterranean environments

Cereals grown on calcareous soils in a dry Mediterranean climate have generally responded to P fertilizer. Broadcasting is the common practice used by most farmers. The effects of rate and method of phosphate placement on dry matter production (TDM), grain yield and P uptake by durum wheat (Triticum vulgare L.) were investigated. Factorial experiments with four levels of P (0, 17.5, 35, and 52.5 kg P ha−1) and 2 methods of application (banding by drilling with the seeds, and broadcasting before surface tillage and sowing) were conducted for three consecutive seasons at three experimental sites: Breda (Typic Calciorthid, 281 mm); Tel Hadya (Chromoxeretic Rhodoxeralf, 328 mm) and Jindiress (Palexerollic Chromoxerert, 471 mm). Three levels of P were used in the third season only. Treatments were replicated in three blocks. The average values of NaHCO3-extractable P in the plow layer were 2.8, 3.7 and 2.1 mg P kg−1 at Breda, Tel Hadya, and Jindiress, respectively. Above-ground total dry matter (TDM) was determined at tillering and anthesis. Grain and straw yields were estimated separately at harvest. The P concentration in plant material was determined at both stages. At tillering, TDM and total P uptake (TPU) increased linearly with the rate of P applied. It was found that (i) 17.5 kg P ha−1 banded was as effective in increasing TDM and TPU as 52.5 kg P ha−1 broadcast, and (ii) the average relative percentage increase in TDM at tillering due to P banded as compared to P broadcast was 54%, with significantly less response to banding, by maturity and harvest. The response to P placement was found to be site related. At Breda, banding was found superior to broadcasting in all 3 seasons with a relative increase in grain yields equivalent to 34, 63 and 23% in the 3 successive seasons, when optimum amounts of P were applied. However, in two out of three seasons only banding was found superior to broadcasting at both Tel Hadya and Jindiress. As a result, banding P is recommended for durum wheat grown on the calcareous soils of the Mediterranean regions because it stimulates growth and P uptake early in the season and increases the crop potential for good grain and straw yields especially in dry areas. Given equal rates of P application, banding was found superior to broadcasting in most cases.

Age-associated alterations in human natural killer cells: 2. Increased frequency of selective NK subsets

We have analyzed the peripheral blood lymphocytes from healthy volunteers (20 to 94 years) for the expression of natural killer (NK) cell surface markers, NK activity, and B-cell proliferative response. An increase (2- to 3.5-fold) in relative percentage and absolute number of lymphocytes expressing Leu-7 (HNK-1) or Leu-11a (CD 16) antigen was found in the elderly group (>80 years) as compared to young adults (<40 years). A two-color immunofluorescence analysis revealed that the age-associated increment was both progressive and selective; the actual increase occurred in Leu-7 +11a + and Leu-7 +11a − populations (subsets with variable and weak NK activity) but not in the Leu-7 −11a + (most active) subset. There is a corresponding decrease in the 7 − 11a − cells. The ratios of 7 +11a ++ 7 −11a + and 7 +11a − 7 −11a + cells doubled with advancing age. Linear regression analysis suggests that the 7 −11a + cells are highly preserved through human senescence and the ratio of 7 +11a − cells to the most stable subset, 7 −11a +, could expand nearly 100-fold from birth to old age. Further analysis of Leu-7 + cells for the coexpression of Leu-11c (an epitope of Leu-11a) confirmed a similar pattern of changes in 7 +11c + and 7 +11c − NK subsets with advancing age. The frequency of Leu-11 + (epitopes 11a + or 11c +), but not of the subsets of 7 + phenotype (7 +11a − or 7 +11c −), correlates well with the NK activity (spontaneous killing of K562 tumor cell line). The 7 +11c + cells may directly or indirectly be responsible for the increase in NK activity observed with a majority of aged donors. The inverse relationship observed between the mitogenic response of lymphocytes to pokeweed mitogen (PWM) and the initial frequency of 7 +11a −, but not other phenotypes, raises a potential functional significance for the expansion of the 7 +11a − (7 +11c −) subset. These age-associated NK phenotypic changes provide a cellular basis for our observations on age-associated increase in NK activity and decrease in mitogenic response to PWM.

Pulmonary effects of acute vanadium pentoxide inhalation in monkeys.

An experimental study was conducted to investigate the hypothesis that changes in pulmonary function induced by vanadium pentoxide (V2O5) inhalation would be accompanied by evidence of pulmonary inflammation. Sixteen adult, male cynomolgus monkeys were acutely exposed by whole-body inhalation of V2O5 dust at aerosol concentrations of 0.5 mg V2O5/m3 and 5.0 mg V2O5/m3, conducted at a 1-wk interval. Comprehensive pulmonary function tests were performed 1 day after each inhalation exposure to detect functional changes in the airways and pulmonary parenchyma. Pulmonary inflammation was assessed by cytologic analysis of respiratory cells recovered from the lower respiratory tract by bronchoalveolar lavage (BAL). Postexposure values for pulmonary function and BAL were compared with the baseline values determined for each monkey prior to V2O5 exposure. Acute V2O5 dust inhalation produced significant air-flow limitation in both central and peripheral airways without producing any detectable changes in parenchymal function. These functional changes were accompanied by a significant increase in the total cell counts recovered from the lungs by BAL. The increase in total cell count occurred through a dramatic increase in absolute number and relative percentage of polymorphonuclear leukocytes (PMN). These findings suggest that pulmonary inflammatory changes involving PMN may play an important role in the occurrence of air-flow limitation after acute inhalation of V2O5 dust.

Comparison of Fluorescence and Photodynamic Activities of Whole Hematoporphyrin Derivative and Its Enriched Active Components&lt;xref ref-type="fn" rid="FN2"&gt;2&lt;/xref&gt;

The in vivo biologic activities of the hematoporphyrin derivative (Photofrin) and the enriched, so-called "active fraction" (Photofrin II) were determined by measuring the necrosis produced in implanted tumors in DBA/2Ha mice exposed to various total doses of light (20-100 J/cm2) after ip administration of 10 mg/kg standard doses of either Photofrin or Photofrin II. Total relative percentage increase in fluorescence in tumor tissue, as compared to fluorescence in control tissue, also was measured for both Photofrin and Photofrin II. In response to total light doses (630 nm) of 40-100 J/cm2, mice that received Photofrin had comparable amounts of tumor necrosis to those mice that received Photofrin II. At doses of 40-60 J/cm2, 80% tumor destruction resulted, and at 80-100 J/cm2, tumor destruction was 100%. However, at a total light dose of 20 J/cm2, the tumors that received Photofrin II exhibited 60-80% tumor necrosis, whereas those animals that received Photofrin had only small areas of patchy necrosis associated with signs of vascular thrombosis and hemorrhage into the surrounding perivascular stroma. A 25.2% total increase in maximal tissue fluorescence over that in controls was observed for animals that received Photofrin II, as compared to 13.9% for those animals that received Photofrin. It is concluded that the greater demonstrable efficacy of treatment with Photofrin II, as compared to treatment with Photofrin, is due to enrichment of those nonpolar hydrophobic components of the hematoporphyrin derivative mixture that are thought to be primarily responsible for the in vivo biologic activities.

Effects of oxprenolol on the intra-arterial blood pressure response to dynamic exercise in hypertensive men.

The intra-arterial blood pressure of 20 male patients with essential hypertension was continuously recorded during dynamic exercise. Graded exercise testing on a bicycle ergometer and a stair-climbing test were performed prior to and during treatment with oxprenolol. Acute oxprenolol therapy was associated with a reduction in heart rate but little reduction in blood pressure. Chronic treatment for 14.3 weeks with oxprenolol (mean daily dose, 344 mg) was associated with a substantial reduction of blood pressure at rest and at each level of bicycle exercise. A similar antihypertensive effect was demonstrated during stair climbing. The normal blood pressure response to exercise as assessed by the relative (percentage) increase in pressure above the pre-exercise level and the rate of increase in blood pressure (per unit of work), as well as exercise tolerance, were unchanged by chronic beta-blockade with oxprenolol.

Studies of human lymphocytes in the newborn and the aged

Proportions and absolute numbers of T and B lymphocytes were determined among 30 newborn infants and a group of 77 elderly patients 60 to 95 years of age. Total lymphocytes in the cord blood of the newborn showed a distinct elevation in total numbers of T and B lymphocytes (p < 0.005) as compared to that in blood from normal adult controls, reflecting the relative lymphocytosis of infancy. Proportions of cord blood T lymphocytes as reflected by the sheep cell rosette technic were considerably lower than those in lymphocytes from normal adult controls, however, proportions of cord blood T lymphocytes as determined by indirect immunofluorescence were not significantly different from those in controls. Old people showed a significant reduction in total numbers of lymphocytes (p < 0.005) when compared with those in normal adult controls 18 to 51 years of age. Moreover, there was a significant increase in the relative proportions of peripheral blood B lymphocytes in the elderly although the absolute numbers of B cells did not differ from those in younger controls. A significant decrease in total numbers of T cells as measured both by sheep cell rosettes and indirect immunofluorescence was recorded among older patients (p < 0.001). In addition, there was a broad increment in the incidence of various autoantibodies (antinuclear, anti-IgG, antismooth muscle, antimitochondrial and antiparietal cell) among the old people studied. No direct correlation could be determined between relative B-cell percentage increase or T-cell decrease and the presence of various autoantibodies in individual patients. Diminution in total lymphocyte counts as well as absolute numbers of T cells in the elderly may provide the cellular basis for an increased susceptibility to neoplasia and infection.

Effect of aqueous solutions of cuprammonium complexes on the machinability of brass

Thermodynamic analysis of the conditions under which the environment has a physicochemical effect on the mechanical properties of solids (the Rebinder effect) gives grounds for the view that fracture in solids may be facilitated by irreversible chemical reactions taking place on their surfaces [1, 2] as well as by the action of related (similar in molecular nature) liquid media. This permits examination from a common viewpoint of an extensive series of processes in which the environment affects the mechanical properties of solids: from purely physical adsorption to purely chemical reaction, for example, during the stresscorrosion cracking of metals and alloys. It is an essential condition for these processes that the energy of the solid-environmen t reaction should be commensurate with the surface energy [3], similar to the situation occurring when a solid is in contact with a related environment [4]. The purpose of our work was the experimental study of the effect of a chemically active environment on the mechanical properties of a solid material under conditions as favorable as possible for fracture to be facilitated as a result of surface reactions. Forced localized fracture (scratching with a diamond point) makes it possible to compare the results obtained with the facilitation of metal machining in the presence of metallic fusions previously studied in [5], a classic example of a reduction in strength resulting from a crop in surface energy; the system studied (brass solutions of ammonia and its derivatives) provides an opportunity for comparing the facilitation of fracture discovered with the patterns of stress corrosion. The investigation was carried out with a specially designed pendulum-type scratch sclerometer. The linear dimensions of the scratch (its width for the most part) were recorded at a constant level of dissipated energy (identical initial amplitude of pendulum swing), as was the speed of pendulum oscillation damping, which is proportional to the coefficient of friction (the linear reduction in amplitude with time characteristic of dry friction was established by preliminary experiments). The relative percentage increase in scratch width was taken as the measure of the effect of the environment on strength. During the experiments, the concentration of ammonia and of bivalent copper in the solution was varied over a wide range. The test agent was prepared by mixing solutions of ammonia and of copper salt of identical percentage concentrations in specified proportions. The liquid obtained was applied by pipette to the carefully polished surface of a brass plate on which a diamond cutting tool connected to the pendulum had made a scratch in about 100 consecutive passes; the cutting tool was pressed against the plate by a constant force. The test results showed that solutions of cuprammonium complexes in specified concentrations could greatly facilitate the fracture of alpha brass (Fig. 1). In these circumstances an increase in the coefficient of friction can be detected in this concentration region. Pure ammonia does not facilitate fracture; what is more, at high ammonia concentrations there is a considerable drop in friction and a reduction in the depth of the scratch as a result of tool slippage. It was necessary to study the connection between the data obtained by us and the composition of the solutions used in the experiments, because contradictory opinions are expressed in the literature on stress corrosion of alpha brass in cupramm0nium solutions as to precisely which ammonia complex is responsible for the fracture.

STUDIES OF INCORPORATION OF RADIOACTIVITY INTO LIPIDS BY HUMAN BLOOD. II. PATTERN OF INCORPORATION OF RADIOACTIVITY INTO FATTY ACIDS BY PLATELETS FROM NORMAL SUBJECTS AND PATIENTS IN DIABETIC ACIDOSIS.

Platelets from diabetics in acidosis incorporate significantly less C-14 into fatty acids than do platelets from control subjects. This decrease in incorporation of C-14 into fatty acids is not uniform. Incorporation of C-14 into myristic and palmitic acids, fatty acids presumably made by de novo synthesis, is suppressed to a much greater extent than is incorporation into other fatty acids. Since some of these abnormalities of incorporation of C-14 by platelets from comatose diabetics could represent isotope dilution effects, we have been particularly interested in the analysis of these data in terms of percentage of total fatty acid C-14 incorporated into the various groups of fatty acids. Platelets from diabetics in acidosis have a pattern of incorporation of C-14 into platelet fatty acids which is much different from that of normal platelets. There is a great decrease in percentage of C-14 in myristic and palmitic acid with a relative increase in percentage of C-14 in fatty acids with retention time corresponding to arachidic acid (20:0) or greater. A significant increase in relative percentage of C-14 in fatty acids containing ten carbons or less is also seen. These findings presumably mean that the cytoplasmic or malonyl CoA pathway, which is involved primarily in synthesis of palmitic and myristic acids, is suppressed greatly in diabetic acidosis, while the mitochondrial or chainlengthening pathway is suppressed to a much smaller degree, or is actually stimulated. It is, therefore, important to consider qualitative as well as quantitative alterations in fatty acid synthesis in diabetes.

The effect of corticotrophin and cortisone on uterine glycogen in the rabbit.

ABSTRACT Cortisone (but not corticotrophin) increases the glycogen content of the rabbit uterus. The relative percentage increase in glycogen is twice as large in oestradiol-treated as in untreated spayed rabbits, suggesting a preferential enhancement by cortisone of the glycogenopoietic action of oestradiol on the uterus. Increased glycogen deposition is noted wherever glycogen is normally present in controls receiving no cortisone, i. e., in the myometrium of spayed rabbits and in the endometrium and myometrium of spayed rabbits receiving oestradiol.