Significant Differences In Control Research Articles

Lipoprotein abnormalities in hyperlipidemic and normolipidemic men on hemodialysis with chronic renal failure.

Lipids, lipoproteins, apolipoproteins (apo) and apo E polymorphism were determined in 101 men with chronic renal failure (CRF) were were on hemodialysis and 101 healthy controls matched for age and sex. Patients with CRF on hemodialysis had significantly higher levels of serum triglycerides, very-low-density lipoprotein (VLDL) cholesterol, intermediate-density lipoproteins (IDL), and lower levels of low- and high-density lipoproteins (LDL and HDL, respectively) than controls. Regarding apolipoproteins, serum apo B concentrations were decreased. Apo C-III concentrations in sera and in VLDL and HDL fractions were significantly increased in 35 hemodialysis patients compared with 32 controls. Seventy-eight of the 101 CRF patients had normal serum cholesterol and triglycerides (less than 5.2 mmol/liter and less than 2.3 mmol/liter, respectively). However, this subgroup also showed a significant increase in VLDL-triglycerides and serum apo E concentration in addition to changes observed in the group as a whole. Apo E polymorphism in our study population did not differ from that reported for other European populations. According to the different apo E phenotypes, lipids and lipoprotein composition showed no significant differences in controls or patients. We conclude that accumulation of triglyceride-rich lipoproteins in patients with CRF on hemodialysis may thus be at least in part related to the enrichment of apo C-III in VLDL and HDL fractions. Lipoprotein profile in hemodialysis patients, including those with normal serum cholesterol and triglyceride levels, is consistent with high cardiovascular risk.

Protein turnover, growth and proliferation in CHO cells. Variation within and between mutant classes for salvage pathway enzymes.

We have examined the clonal variation in rates of amino acid transport, protein synthesis, protein degradation, growth and proliferation for CHO cells with mutations in the purine and pyrimidine salvage pathways. First we compared three clonal cell lines, each with a different mutation, with the heterozygous parental line AT3-2. Overall, the correlation between rates of protein turnover, growth and proliferation was excellent. The slower growth and proliferation of one mutant, AB3 (TK-, APRT-), is explained by a low intrinsic rate of protein synthesis coupled with a smaller response in rates of amino acid transport, protein synthesis and protein degradation to insulin, serum and dexamethasone. Secondly, we compared seven aza-adenine-resistant and 14 thioguanine-resistant mutants of AT3-2 and found significant differences in control and insulin-stimulated rates of protein turnover both within and between mutant populations. A significant difference between the populations was unexpected because each individual cell line was cloned from a spontaneous pre-existing mutation in AT3-2, and each population should have the same average rate. Remarkably, all 24 mutants had lower rates of protein synthesis than AT3-2. We cannot explain the data solely in terms of mutations in the salvage pathways. Rather, we propose that the mutant survivors have randomly down-regulated the intrinsically fixed growth factor-regulated pathways of protein turnover, resulting in a broad spectrum of lower metabolic rates.

Field Evaluation of Benomyl to Control Cylindrocladium Fruit Spot of Custard Apple.

Cylindrocladium leaf and fruit spot caused by Cylindrocladium colhounli is a recently reported disease of custard apple (Annona cherimola x A, squamosa). The fungus defoliates leaves and renders fruit unsaleable. A field spray trial showed that seven fortnightly applications of benomyl at 0.25 g, 0.5 g and 1.0 g a.i./L significantly reduced the incidence of disease compared to unsprayed trees. There were no significant differences in control achieved by different rates of benomyl. The levels of benomyl residue in fruit sprayed with the two higher rates were below 2 ppm, 7 days after the last application. The lower rate (benomyl 0.25 g a.i./L) should be recommended to control disease under orchard conditions.

Tumor promoter 12‐0‐tetradecanoyl‐phorbol‐13‐acetate (TPA) can reduce the Ca‐transporting ability of Ca‐lonophores in T lymphocytes: The involvement of intracellular heavy metal lons

12-0-tetradecanoyl-phorbol-13-acetate (TPA) can significantly reduce the Ca-ionophore-induced rise in the intracellular calcium concentration (Cai) of T lymphocytes measured by quin2 or fura-2 fluorescence. This counteraction of TPA is maximal at a preincubation of 90 min at TPA concentrations higher than 20 nM. 45Ca uptake and efflux measurements directly indicate that TPA does not activate the calcium extrusion systems in thymocytes but impairs the Ca-transporting ability of Ca-ionophores. TPA causes no immobilization of the Ca-ionophores as it is demonstrated by the lack of significant changes in fluorescence and fluorescence polarisation of A23187 during TPA incubation. Similarly the energy transfer between the Tyr, Try groups of membrane proteins and A23187 shows no significant difference in control and TPA treated thymocytes. This indicates that A23187 is not in a membrane protein-bound form after TPA preincubation. The intracellular heavy metal chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) restores the ionophoretic ability of Ca-ionophores in TPA pretreated cells to the control level. Diacyl-glycerols also impair the Ca-transporting ability of Ca-ionophores. TPEN prevents this effect as well. These findings suggest that TPA and diacyl-glycerols may cause an increase in the availability of intracellular heavy metal ions. Our results may reflect a new, physiologically important mechanism of the action of diacyl-glycerols and phorbol esters.

Tubuloglomerular feedback after nephron or ureteral obstruction.

The effects of 1 day of single nephron, unilateral ureteral (UUO), and bilateral ureteral (BUO) obstruction on tubuloglomerular feedback were studied in anesthetized rats. Stop-flow pressure (SFP) was measured as an index of glomerular capillary pressure before, during, and after loop of Henle microperfusion. Tubuloglomerular feedback (delta SFP) showed an increased sensitivity to low loop perfusion rates and an increased maximal response after 1 day of single nephron obstruction or relief of UUO. Tubuloglomerular feedback was not significantly different from normal after release of BUO. Whole kidney glomerular filtration rate (GFR) was about 10% of normal after release of ureteral obstruction, and single nephron glomerular filtration rate (SNGFR) averaged one-third of normal. Paired measurements of SNGFR from proximal and distal tubules revealed no significant differences in control or in BUO kidneys, but a significant proximal-distal SNGFR difference was observed after UUO. The results suggest that tubuloglomerular feedback does not significantly contribute to the low GFR after release of BUO; after release of UUO, approximately one-fourth of the fall in GFR may be due to activation of the feedback mechanism.

ACEPHATE AND AVERMECTINS FOR GERMAN COCKROACH CONTROL1

Acephate (1%), acephate (1%) plus 0.16% zinc ricinoleate (a deodorant) and 0.08% Tryfac 910-K® (a surfactant), and avermectins (0.02 and 0.1%) were applied in kitchens of single-family dwellings infested with Blattella germanica (L.). All gave control at 2, 4, and 8 weeks after initial application. There was no significant difference in control between insecticides or concentrations.

Permeability of intestinal microvessels in chronic arterial hypertension.

We studied changes in intestinal microvascular permeability resulting from chronic arterial hypertension. Normotensive dogs and dogs made chronically hypertensive utilizing the one-kidney, one clip Goldblatt technique were used to obtain values for: arterial pressure, portal pressure, intestinal lymph flow, and the lymph-to-plasma protein concentration ratio (CL/Cp). Values for the normotensive dogs were 111 mm Hg, 7.1 mm Hg, 6.2 ml/hr, and 0.64, respectively, while values for the chronically hypertensive dogs were 165 mm Hg, 7.3 mm Hg, 12.5 ml/hr, and 0.66, respectively. Control lymph flow in the hypertensives was 100% greater than in the normotensives, while there was no significant difference in control CL/Cp between the two groups. When portal venous pressure was acutely increased to 30 mm Hg, lymph flow increased to approximately the same maximum value in both groups. This represents an eightfold increase in normotensive and a fourfold increase in hypertensive lymph flows. The reflection coefficient determined as 1 - (CL/Cp) for total proteins at maximum lymph flow was 0.78 for the normotensives and 0.56 for the hypertensives. An electrophoretic analysis indicated sieving of large molecular weight protein fractions was considerably reduced in the hypertensives when compared to the normotensives. Our results indicate a significant increase in intestinal microvascular permeability to macromolecules resulting from the one-kidney, one clip Goldblatt model of chronic arterial hypertension.

Status and control in voluntary community health planning groups.

A field study was conducted to examine the relative control of provider and consumer members of HSA Project Review Committee. Three project review committees chosen at random during a single HSA review cycle were observed throughout the decision-making process using Interaction Process Analysis. Results indicated that there were no significant differences in control between the provider and consumer members when considered as subgroups of the review committees. Findings also confirm the critical role of the chairperson in the organization and function of the group. It can be concluded that the occupational prestige of provider or consumer members is not imported into the planning situation to a sufficient degree to allow either the provider or consumer subgroup to dominate the planning process. Innovations in health care planning such as long-term education in health planning, group processes, and related issues should be attempted to enhance the effectiveness of these groups.

Studies on lymphocyte hyporesponsiveness in cirrhosis: The role of increased monocyte suppressor cell activity

We investigated the possibility that monocyte suppressor cells play a role in the peripheral lymphocyte hyporesponsiveness of chronic liver disease by utilizing assays of monocyte-mediated suppressor activity in 46 patients with chronic liver disease and 46 controls. The percent change achieved by the addition of indomethacin to a PHA-induced proliferative response was significantly increased in patients with cirrhosis compared with controls (p < 0.001). The increase was seen in cirrhosis regardless of etiology but was not found in patients with chronic hepatitis without cirrhosis. The effects of indomethacin were abolished by monocyte depletion and were greater in autologous serum than in pooled AB serum (p < 0.02). Monocyte depletion in cirrhotic patients significantly increased the lymphocyte response to PHA (p < 0.005) but made no significant difference in controls. There was a significant correlation between the indomethacin-induced changes and the changes in lymphocyte response to PHA on monocyte depletion (r = 0.6583, p < 0.01). Our initial results led us to study the mode of action of the inhibitory effect of cirrhotic serum on lymphocyte response to PHA. Cirrhotic serum significantly reduced the response of normal lymphocytes compared with control serum (p < 0.02), but the difference was abolished by adding indomethacin and by monocyte depletion. These results suggest that monocyte suppressor cells may play a role in the depressed cellular immunity seen in some patients with cirrhosis. The inhibitory effect of cirrhotic serum appears to be in part monocyte mediated and prostaglandin dependent.

Effects of Wetting Agent, Stage of Growth, and Species on the Selectivity of Diclofop

A 2-yr field study was conducted to determine whether the addition of wetting agents to diclofop {2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid} could enhance its postemergence control of grass weeds without altering its crop tolerance. In each year, 12 species were treated at two stages of growth with at least two concentrations of diclofop. Regardless of the treatment, selectivity was not altered on wheat (Triticum aestivumL.), soybeans [Glycine max(L.) Merr.], cucumber (Cucumis sativusL.), or sorghum [Sorghum bicolor(L.) Moench]. The addition of wetting agent to diclofop was of no value on highly susceptible grass weed species such as barnyardgrass [Echinochloa crus-galli(L.) Beauv.] or on the more resistant species such as large crabgrass [Digitaria sanguinalis(L.) Scop.]. Only on an intermediately susceptible species such as giant foxtail (Setaria faberiHerrm.) could any significant differences in control be attributed to a wetting agent. The stage of growth of the grass weed species at time of treatment and the diclofop concentration were more important than the presence of a nonionic wetting agent.

Advanced squamous cell carcinoma of the oral cavity and oropharynx treated with irradiation and surgery.

One hundred and sixteen patients with advanced squamous cell carcinoma of the oral cavity and oropharynx were treated with irradiation and surgery. Failures were correlated with respect to tumor factors and treatment. Associated with failures are: (a) cut-through of disease at the primary site, (b) connective tissue involvement in the neck, (c) insufficient dose or use of a wedge pair, and (d) failure to give elective treatment to the neck. There is no significant difference in control in the pre- vs. the postoperative group. Combined treatment is indicated in those patients with a high risk of failure if treated by either modality alone.

Effect of Molasses as a Spray Additive for Control of the Bollworm and Tobacco Budworm1

Blackstrap molasses was used as an additive with methyl parathion, a mixture of Strobane® (terpene polychorinates (65% chlorine)) and monocrotophos, and a mixture of Strobane, DDT, and methyl parathion in 5 field and laboratory tests against the bollworm, Heliothis zea (Boddie), and the tobacco budworm, H. virescens (F.). Addition of molasses to a toxicant produced a significant difference in control only 1 time in 8 comparisons made in 5 field tests and 1 laboratory test. Seven times out of 8 the differences among treatments were too small to be significant, although numerical differences favored molasses in each case. The 1 test where the molasses treatment was significantly better than the toxicant used alone was in a field test against a heavy infestation. The residual activity of methyl parathion was markedly extended with the addition of molasses in the laboratory test. One gallon of molasses was superior to ½ gallon per acre. The phytotoxicity of methyl parathion was reduced in 1 field test with addition of molasses.

The role of lactic acid in gas secretion in the teleost swimbladder

1. 1. Existing evidence for the mechanism of gas secretion into the swimbladder of fish suggests that lactic acid is produced by the gas gland tissue in the presence of high oxygen pressure and is responsible for the “single concentrating effect” (Kuhn & Kuhn, 1961) which is multiplied by countercurrent blood flow through the rate mirabile to produce the necessary gas pressure. 2. 2. The catabolism of the gas gland tissue of the vermilion rockfish, Sebastodes miniatus, a species whose ecological depth range extends down to 200 m, has been investigated under O 2 pressures up to 51 atm. Lactic acid was produced by the tissue throughout the range of pressures investigated, and no evidence of a Pasteur effect was found. CO 2 production by the tissue was similar and very low under both O 2 and N 2 and suggested that citric acid cycle enzymes and oxidative phosphorylation systems were very weak in this tissue. 3. 3. The maximum glycolytic rates observed were too low to account for pre- and post-rate differences in lactate concentration observed by other workers, and glycogen levels in the gas gland tissue (0·02 mg/mg dry wt.) could produce the observed arteriovenous differences in lactate for only a few minutes. 4. 4. The essential role of lactic acid in gas secretion was supported by injecting oxamic acid, a competitive inhibitor of lactic dehydrogenase, into the swimbladder of deflated fish; statistically significant differences in control and experimental groups in both amounts and relative percentages of gases secreted were observed.

Tests with ixodicides for the control of the tick vectors of Kyasanur Forest Disease.

Ixodicides were evaluated in India in laboratory tests, area treatment tests, and when applied to cattle for the control of the tick vectors, Haemaphysalis spp., of Kyasanur Forest Disease. When adult H. spinigera Neumann, H. turturis Nuttall & Warburton, and H. papuana kinneari Warburton were dipped in 3 ixodicides in the laboratory, there was little difference between sexes in susceptibility to the ixodicides. (Ticks were held for 1 day and those unable to turn over were recorded as dead.) The relative toxicity of the ixodicides was: γ isomer of benzene hexachloride = lindane>carbaryl>malathion. An emulsion of lindane, and a suspension and dust of benzene hexachloride (13% γ isomer) were used at rates of 0.11, 0.28, 0.56, and 1.12 kg of lindane or γ isomer/hectare (0.1, 0.25, 0.5, and 1.0 Ib/acre) to control nymphs of H. spinigera and H. turturis on the forest floor, and plots were flagged for ticks pretreatment and at 1 day and weekly for 6 weeks posttreatment. Analysis of the transformed data (X1 = √X + 0.5) showed that there were no significant differences in control between formulations, but the rate of 1.12 kg/hectare gave significantly more control than the rate of 0.11 kg/hectare. Cattle were sprayed or dusted, and the most effective treatments, 0.5% malathion, 0.25 and 0.5% carbaryl, and 0.01 and 0.03% lindane or γ isomer of benzene hexachloride gave significant control of ♂♂ of H. bispinosa Neumann for 3–7 days and of ♀♀ for –3 days. With most treatments, ticks were first found on the cattle at 1–2 days posttreatment.

The effect of formulation and method of applying dieldrin on the control of clover root weevil (Amnemus spp.) and on residue levels on pastures

Methods of application of different formulations of dieldrin were examined for the control of clover root weevil (Amnemus spp.) and for residue levels on pasture foliage. Two experiments were conducted : the first in which the effectiveness against clover root weevil of surface and sub-surface application of dieldrin granules and the surface application of dieldrin emulsion, was compared ; the second in which the residues of dieldrin on pasture foliage were determined at intervals of one, two, and four weeks after the surface and sub-surface application of dieldrin granules and the surface application of dieldrin dust and emulsion. Granular diazinon was screened as a possible alternative to dieldrin in the first experiment. Clover root weevil control was obtained with dieldrin, regardless of the formulation and method of application, with no significant difference in control between treatments. Diazinon granules were ineffective. The initial residues of dieldrin were highest with the surface application of emulsion, dust, and granules in that order and lowest with sub-surface granule application. Two weeks after the application of surface and sub-surface granules and four weeks after the application of dust and emulsion, residues fell below the level detectable by the method used.

The Treadle Sprayer and the Cable-Type Back Rubber for Control of Biting Flies on Cattle in Pennsylvania1

The effectiveness of various insecticide-repellent formulations applied by means of self-treating devices for the control of the horn fly, Siphona irritans (L.), and the stable fly, Stomoxys calcitrans (L.), on Cattle under Pennsylvania conditions was tested during 1955 and 1956. A spray containing 50% butoxy polypropylene glycol and 5% methoxychlor in methylated naphthalenes was tested during 1955 with a treadle sprayer and a cable-type back rubber. With the treadle sprayer, an average of 90.0% control of the horn fly and 34.7% control of the stable fly resulted when one round-trip application was made daily. Because of the excitement and nervousness caused among the animals, approximately one-third of the animals going through the sprayer received only partial treatment or none at all. The back rubber installed in a small pasture with a few trees accomplished almost perfect control of the horn fly, but less satisfactory control of the stable fly. A significant decrease in effectiveness was noted when the back rubber was located in a pasture with numerous dead trunks and branches, but no decrease was observed in wooded pastures devoid of dead trunks and branches. Studies of the residual effect showed that control of the horn fly throughout a post-treatment period of 25 days varied from 52.5 to 99.7%. The residual effect against the stable fly lasted for only 15 days, control varying from 33.0 to 54.4%. In 1956, units of the portable model of the rubbing device, treated with four insecticide-repellent formulations including butoxy polypropylene glycol, methoxychlor, Lethane 384 and synergized pyrethrins, were installed indoors in a basement barn, and in three pastures of different sizes and with different numbers of trees, but relatively free of dead trunks or stumps. All formulations provided effective and consistent control of the horn fly. No significant difference in control was found among the four formulations tested under the different conditions. It was noted that 5% methoxychlor in diesel oil provided excellent control of the horn fly and that the addition of butoxy polypropylene glycol did not significantly enhance the effectiveness of methoxychlor. None of the four formulations tested provided satisfactory control of the stable fly and there was considerable variation in the effectiveness of each formulation. None of the materials tested on the back rubber had any apparent adverse effects on the animals used in the experiments.