SP Treatment Research Articles

Suppression of androstenone in entire male pigs by anabolic preparations

At an age of 19 weeks and an average weight of 80.5 kg, four boars each were implanted i.m. with two doses of either Synovex-H ® (SH; total dose 400 mg testosterone propionate+40 mg oestradiol benzoate) or Synovex Plus ® (SP; total dose 400 mg trenbolone acetate+56 mg oestradiol benzoate), respectively. A third group of four boars served as control. The animals were slaughtered 5 weeks after implantation and the testes weights recorded. Hormone (androgen and oestradiol benzoate) residues in implantation sites were quantified by high-performance liquid chromatography with UV detection, and the boar taint steroid androstenone was determined in fat by enzyme-immunoassay (EIA). Gas chromatography–mass spectrometry analysis additionally confirmed the identity. Plasma testosterone and trenbolone concentrations were measured by EIA. Plasma testosterone and fat androstenone concentrations were reduced to basal levels by the SP treatment. With SH the decrease in fat androstenone concentrations was inconsistent between animals. Androgen and estrogen residues in implantation sites were higher in SH boars than in SP boars (179 mg+19 mg versus 85 mg+15 mg, respectively). Besides the resulting higher resorbed doses, the higher SP efficiency was attributed to greater hypothalamic negative feedback activity of trenbolone compared with testosterone. Including the implantation site, whole batches of processed meat products would be contaminated above the international threshold levels for these hormones in meat.

Persistent ICT malaria P.f/P.v panmalarial and HRP2 antigen reactivity after treatment of Plasmodium falciparum malaria is associated with gametocytemia and results in false-positive diagnoses of Plasmodium vivax in convalescence.

A problem with rapid Plasmodium falciparum-specific antigen histidine-rich protein 2 (HRP2) detection tests for malaria is the persistence of antigen in blood after the disappearance of asexual-stage parasitemia and clinical symptoms, resulting in false-positive (FP) test results following treatment. The ICT P.f/P.v immunochromatographic test detects both HRP2 and a panmalarial antigen (PMA) found in both P. falciparum and Plasmodium vivax. To examine posttreatment antigen persistence with this test and whether persistent sexual-stage forms (gametocytes) are a cause of FP tests after treatment, we compared serial antigen test results with microscopy results from patients symptomatic with P. falciparum malaria in Indonesia for 28 days following treatment with chloroquine (CQ; n = 66), sulfadoxine-pyrimethamine (SP; n = 36), and artesunate plus sulfadoxine-pyrimethamine (ART + SP; n = 15). Persistent FP antigenemia following SP treatment occurred in 29% (HRP2) and 42% (PMA) of the patients on day 7 and in 10% (HRP2) and 23% (PMA) on day 14. The high rates of persistent HRP2 and PMA antigenemia following CQ and SP treatment were strongly associated with the presence of gametocytemia, with the proportion with gametocytes on day 7 posttreatment being significantly greater in those with FP results than in those with true-negative PMA and HRP2 results. Gametocyte frequency on day 14 post-SP treatment was also greater in those with FP PMA results. Following SP treatment, PMA persisted longer than HRP2, giving an FP diagnosis of P. vivax in up to 16% of patients on day 14, with all FP P. vivax diagnoses having gametocytemia. In contrast, PMA was rapidly cleared following ART + SP treatment in association with rapid clearance of gametocytemia. Gametocytes appear to be an important cause of persistent posttreatment panmalarial antigenemia in areas of endemicity and may also contribute in part to persistent HRP2 antigenemia following treatment.

Bromide and Atrazine Leaching in Furrow‐ and Sprinkler‐Irrigated Corn

Irrigation method is an important consideration in the management of nutrients and pesticides. A 2‐yr study was undertaken to evaluate Br− and atrazine [6‐chloro‐N‐ethyl‐N'‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] leaching following uniform spray application in a corn (Zea mays L.) field under three irrigation treatments: (i) furrow irrigation with water placement in every furrow (EF), (ii) furrow irrigation with water placement (at twice the rate) in alternate furrows (AF), and (iii) sprinkler irrigation (SP). The soil, a Fort Collins clay loam (fine‐loamy, mixed, superactive, mesic Aridic Haplustalf), was ridged and furrowed for all irrigation treatments. In both years of the study, Br− movement under all three irrigation treatments was dominated by lateral flow into the ridge and/or dry furrow positions. The deepest Br− leaching was found in the SP treatment, but with irrigation scheduled at 100% of evapotranspiration (ET) in no case in either year did Br− mass below the root zone (1.2 m) exceed 3% of applied mass. Comparing the furrow irrigation treatments, applying water at twice the rate to alternative furrows neither increased nor decreased the plot averaged downward movement of Br− Atrazine movement was largely unaffected by the type and placement of irrigation, though in each treatment the downward leaching of atrazine was much greater than expected, suggesting nonequilibrium conditions and/or movement with a mobile reactive phase. A modified version of the unsaturated flow and transport code CHAIN‐2D, which included two‐dimensional root water and solute uptake with partitioning of the soil water into mobile and immobile regions, accurately simulated the Br− concentration profiles. The model will be useful in evaluating management alternatives for the placement of water and chemicals that minimize losses below the root zone.

Biocompatibility of Sweetpotato and Peanut in a Hydroponic System

'Georgia Red' peanut (Arachis hypogaea L.) and TU-82-155 sweetpotato [Ipomoea batatas (L.) Lam] were grown in monocultured or intercropped recirculating hydroponic systems in a greenhouse using the nutrient film technique (NFT). The objective was to determine whether growth and subsequent yield would be affected by intercropping. Treatments were sweetpotato monoculture (SP), peanut monoculture (PN), and sweetpotato and peanut grown in separate NFT channels but sharing a common nutrient solution (SP-PN). Greenhouse conditions ranged from 24 to 33 degrees C, 60% to 90% relative humidity (RH), and photosynthetic photon flux (PPF) of 200 to 1700 micromoles m-2 s-1. Sweetpotato cuttings (15 cm long) and 14-day-old seedlings of peanuts were planted into growth channels (0.15 x 0.15 x 1.2 m). Plants were spaced 25 cm apart within and 25 cm apart between growing channels. A modified half-Hoagland solution with a 1 N: 2.4 K ratio was used. Solution pH was maintained between 5.5 and 6.0 for treatments involving SP and 6.4 and 6.7 for PN. Electrical conductivity (EC) ranged between 1100 and 1200 microS cm-1. The number of storage roots per sweetpotato plant was similar for both SP and SP-PN. Storage root fresh and dry mass were 29% and 36% greater, respectively, for plants in the SP-PN treatment than for plants in the SP treatment. The percent dry mass of the storage roots, dry mass of fibrous and pencil roots, and the length-to-diameter ratio of storage roots were similar for SP and SP-PN sweetpotato plants. Likewise, foliage fresh and dry mass and harvest index were not significantly influenced by treatment. Total dry mass was 37% greater for PN than for SP-PN peanut plants, and pod dry mass was 82% higher. Mature and total seed dry mass and fibrous root dry mass were significantly greater for PN than for SP-PN plants. Harvest index (HI) was similar for both treatments. Root length tended to be lower for seedlings grown in the nutrient solution from the SP-PN treatment.

Effect of spironolactone on lateral mobility of lipids in hepatocyte plasma membranes in the rat

The present study aimed to measure the lateral diffusion coefficient of lipids in hepatocyte plasma membranes ( D l ) by the fluorescence recovery after photobleaching (FRAP) technique using N-4-nitrobenzo-2-oxa-1,3-diasolyl phosphatidylethanolamine (NBD-PE) as a probe after spironolactone (Sp) treatment in rats. D l in male 2-month-old Fischer 344 rats was more than five times faster than the protein lateral diffusion coefficient ( D p) previously determined by the authors. A 4-day pretreatment of rats with a daily dose of 20 mg Sp/100 g body weight significantly increased D l by about 10% ( p<0.01). This finding is in contrast with two previous studies reporting a reduction of the rotational mobility of lipids in hepatocyte plasma membranes after Sp pretreatment, but is in parallel with the changes in D p caused by Sp treatment. We suggest that the lateral mobility of proteins and lipids of hepatocyte plasma membranes as determined by the FRAP technique reflects the membrane functions more realistically than does the rotational mobility of lipids, as determined by the fluorescence anisotropy method.

Effects of water stress cycles on turgor maintenance processes in pear leaves (Pyrus communis).

Effects of water deficits on leaf turgor maintenance processes were analyzed for pear trees (Pyrus communis L. cv. "Barlett") grown in 120-liter containers. Four irrigation treatments were applied: a well-watered control treatment, a spring water stress cycle (Sp), a summer water stress cycle (Su), and a spring plus summer water stress cycle (Sp + Su). For the Sp treatment, water application was progressively reduced from 100 to 20% of the control dose over a period of 27 days in spring. For the Su treatment, water application was progressively reduced over 23 days in summer, from 100 to 20% of the control dose. The Sp + Su treatment comprised both the spring and summer drought stress cycles. Pressure-volume (P-V) curves were constructed and stomatal conductances were determined for pear leaves from each treatment during the spring and summer stress cycles. Leaf water potential (Psi(pi) (0)) and relative water content (R(0)) at the turgor loss point of control leaves tended to decrease from spring to summer. Changes in leaf osmotic water potential at full turgor (Psi(pi) (100)) and in symplast water fraction (R(s)) did not explain the seasonal decrease in Psi(pi) (0). The water stress treatments had no effect on Psi(pi) (100), but R(s) was reduced by the water stress treatments, particularly during the summer stress cycle of the Su and Sp + Su treatments. The decrease in R(s) was correlated with an increase in the slope of the linear region of the P-V curve. Such a coupled adjustment would lead to increased water uptake capacity of water-stressed trees only under non-turgor conditions. Furthermore, pear leaves did not actively accumulate solutes. We conclude, therefore, that changes in leaf tissue water relations as a result of leaf acclimation to water stress are unlikely to facilitate maintenance of fruit productivity under drought.

Insulin-like growth factor-1 in Syrian hamsters: interactions of photoperiod, gonadal steroids, pinealectomy, and continuous melatonin treatment.

Four experiments in Syrian hamsters examined the role and possible interaction of photoperiod, gonadal steroids, and the pineal on circulating levels of insulin-like growth factor-1 (IGF-1). In the first experiment, female hamsters were exposed to long photoperiod (LP; 14:10 LD) or short photoperiod (SP; 8:16 LD); an additional group of SP-exposed females was pinealectomized (PX). SP induced a significant depression in IGF-1 concentrations which PX partially prevented. In Experiment 2, two groups (control and castrate [CX]) of adult male hamsters were kept in LP, and three groups (intact, CX, and CX+PX) of hamsters were kept in SP for five weeks. The four groups of animals that were CX and/or maintained in SP had approximately the same mean level of IGF-1, and all four groups were significantly (P < 0.001) higher than the LP-control hamsters. In Experiment 3, four groups (intact controls, CX, CX+melatonin pellet [MEL PEL], and MEL PEL only) were kept in LP. Melatonin pellets (1 mg melatonin/24 mg beeswax/every two weeks) were implanted sc twice during the experiment. Castration induced a rise (P < 0.001) in IGF-1 levels, and this was not prevented by MEL PEL. In Experiment 4, testosterone and dihydrotestosterone pellets implanted in LP-exposed CX males prevented the CX-induced rise in IGF-1; testosterone implants also reduced IGF-1 levels in CX males treated with progesterone. In conclusion, SP treatment depresses IGF-1 in female hamsters and raises it in males. These results substantiate previous studies in other models of gonadal steroid deficient animals. They lend further credence to the hypothesis that there is a sexual dimorphism in circulating IGF-1 concentrations in the Syrian hamster that may be at least partially related to the presence of gonadal steroids.

Substance P effects on intraspecific aggressive behaviour of isolated male mice

Adult male mice of the Swiss CD1 strain were used to evaluate the effects on isolation-induced aggressive behaviour of a single intravenous administration of substance P (SP; 0.25, 1.0 or 2.5mg/kg dose). All mice were injected 15min before testing (10min videotaped dyadic encounters with an isolated male untreated opponent). Control mice were injected with vehicle. All animals were tested again 24h later in a drug-free state. SP treatment produced a decrease in offensive scores (Attacks and Rattling behaviour), a longer latency to the first Attack episode, and enhanced defensive displays. These effects were reversed 24h later. In no case did SP treatment affect locomotor activity levels or freezing behaviour. A role of SP in the regulation of murine aggressive response is strongly suggested through a direct action of the drug on the central nervous system and specifically on the hypothalamus.

Evaluation of Ac-303630 for Control of Citrus Thrips on Lemons, 1991

Abstract Three rates of AC-303630 and a top of label rate Carzol SP treatment for comparison to the current grower standard were applied to 5 ft tall trees at Sunset Nursery located near Yuma, AZ, on 10 Jul. Plots were 20 ft long and 5.5 ft wide and consisted of a single row of trees spaced 1.5 ft apart. Treatments were made with a C02 powered backpack sprayer calibrated to deliver 27.9 gal/acre at 40 psi with 4 boom mounted T-Jet 8001 nozzles. Ruffer PS was added at 0.25% and 2.0% Penetrator (both Helena Co.) was added to all treatments which were replicated 3 times in a randomized complete block design. Plots were sampled 3, 7, 14, 21, and 28 DAT. Ten terminals per plot were sampled during the morning hours. Sampling consisted of beating a tender terminal over a wire grid mesh screened, internally colored silver can approximately 8 inches deep that contained a white organdy cloth to assist in differentiating and counting nymphs and adult thrips.

Effects of Fansidar on chloroquine-resistant Plasmodium falciparum in Pakistan.

Fansidar (SP), a combination of sulfadoxine and pyrimethamine, was evaluated for its usefulness as a curative agent for treating individual malaria patients and for reducing the community reservoir of Plasmodium falciparum in 4 villages near Lahore, Pakistan, where resistance of 4-aminoquinolines has recently been reported. Following the end of the major malaria transmission season, we carried out a month-long mass treatment campaign during which SP was given to all available villagers who had parasitemias detected during a concurrent house-to-house malaria blood film survey. Of the 82 falciparum patients followed for 14 days after SP treatment, 80 (97.5%) had parasites sensitive to the investigated drug. Parasitemia clearance time after SP was remarkedly short (1.25 +/- 0.53 days; mean +/- SD). However, we were unable to reduce the parasite reservoir of P. falciparum and P. vivax in these villages, probably because we treated only 337, about one-third, of the parasitemic patients. We conclude that SP is an effective drug for treating individual malaria patients from areas in Pakistan where 4-aminoquinoline-resistant parasites are present, but that more research is needed for assessing its usefulness in reducing community reservoirs of malaria.

Reduced Response of Plasma Aldosterone to Acute ACTH Stimulation during Long-Term Treatment with Spironolactone in Essential Hypertension

The response of plasma aldosterone (PA) to ACTH administration (250 micrograms alpha 1-24 ACTH i.m.) before and during treatment with spironolactone (Sp, 75--100 mg/day) for at least 8 months was studied in 11 patients with essential hypertension. These responses were compared with those before and during prolonged treatment with hydrochlorothiazide (Th, 50--75 mg/day), with or without potassium supplement, in 14 hypertensives. PA and plasma cortisol (PC) were determined by radioimmunoassay in which Sp showed minimal cross-reactivity. Both Sp and Th treatments caused similar increases in plasma renin activity accompanied by nearly identical decreases in blood pressure and body weight. PA was also increased by both treatments, but to a significantly greater extent in the Sp-treated group. Serum potassium concentration was increased only by Sp treatment. The response of PA, but not of PC, to acute ACTH stimulation was blunted in the Sp-treated group. That is, the maximal increment of PA above the baseline level was significantly lower during Sp treatment than either before Sp treatment of during Th treatment. These results demonstrate that long-term treatment with Sp can inhibit aldosterone production by acute ACTH stimulation in patients with essential hypertension.

Effect of spironolactone on the distribution of mercury

The distribution and biliary excretion of 203HgCl 2 (0.3 mg Hg/kg) iv was measured in rats treated with spironolactone (SP, 75 mg/kg, ip) for various time intervals. SP had its greatest effect when administered as a single dose 15 min before HgCl 2. SP decreased the concentration of 203Hg in the plasma from 1.5 to 0.05 μg/ml, while it increased the blood concentration from 1.5 to 5 μg/ml. This treatment increased the content of Hg in the lung 12, heart 6, spleen 3, brain 3, muscle 2, stomach 1.7, and liver 1.5 times control, had no effect on the concentration of 203Hg in the intestine, bone, and testes, and markedly decreased the amount in the kidney to 10% of controls. Biliary excretion of Hg was not increased. When SP was administered 90 min or 3 hr before administration of the 203HgCl 2, qualitatively similar but less dramatic effects on the distribution of Hg were obtained. SP administered 15 min after HgCl 2 administration had a similar effect on the distribution of Hg as when administered 30 min before HgCl 2, with the exception that the concentration of Hg in the kidney was not decreased. The two major metabolic products of SP, canrenone and thioacetic acid, were also given to determine their effect on Hg distribution. Canrenone had no effect while thioacetic acid produced an effect similar to that produced by SP. It appears that the alteration in the distribution of Hg after SP treatment is due to the sulfur portion of the molecule. It seems likely that the sulfur moiety complexes the Hg; this complex distributes in the body similar to organic mercurial compounds, which in comparison to inorganic mercurials, reach a lower concentration in the plasma and kidney and a higher concentration in the blood and other tissues. The decrease in the concentration of Hg in the kidney produced by SP is probably responsible for the decreased toxicity of Hg after SP treatment.

Dehulling and Seed Germination in Vernonia Anthelmintica (L.) Willd.1

Fresh seed of four Vernonia anthelmintica (L.) Willd. selections were (1) untreated (N), (2) water soaked overnight (S), (3) soaked overnight followed by removal of pericarp (SP), or (4) soaked overnight followed by removal of pericarp and seedcoat (SPS). The SP treatment increased germination, but many abnormal seedlings resulted, probably due to seedcoat damage during dehulling. A considerable increase in germination followed the SPS treatment. Average shoot length of resulting seedlings approached that of the few normal seedlings after N and S treatments. The factor(s) inhibitory to the germination of fresh vernonia seed is associated with the seedcoat.