Thinning Agent Research Articles

Safety Issues of Hysteroscopic Surgery

The term hysteroscopy is used to determine the procedure during which an endoscopic view of the endometrial cavity is achieved with the help of a type of endoscopic device called "the hysteroscope." Hysteroscopy is used to assist the diagnosis for a series of female pathology. Apart from its diagnostic value, hysteroscopy can also be used for operative procedures including ablation and resection. Both diagnostic and operative hysteroscopy have been used for a number of years and various studies have been published to describe their success and complication rates throughout this period. Diagnostic hysteroscopy is relatively safe, whereas complications occur more frequently when operative hysteroscopy is used. These complications include uterine perforation, hemorrhage, fluid overload, gas embolization, and hyponatremia. The rate in the appearance of these complications is dependent on the type of the hysteroscopic procedure, the distending medium, and the experience of the hysteroscopist. To avoid any problems concerning the application of hysteroscopic procedures, it is important to take the necessary precautions both preoperatively and intraoperatively. For example, the preoperative use of thinning agents of the endometrium and the reduction of the operating time, or the avoidance of cutting too deeply into the myometrium, are some of the parameters to be considered when hysteroscopy is in argument.

THINNING ´ELSTAR´ APPLE WITH BENZYLADENINE

‘Elstar’, the main apple cultivar grown in the Netherlands, requires adequate thinning to reach marketable fruit sizes and to achieve regular yields by preventing alternate bearing. At the moment, chemical thinning of ‘Elstar’ is the only economically feasible way of thinning. Thinning by hand is labour intensive and thus too expensive. Furthermore, hand thinning is usually carried out after June-drop, by which time only increases in fruit size are achieved and no reduction in alternate bearing. Up to 2004, carbaryl was the only effective fruit-thinning chemical Dutch growers had at their disposal. However, carbaryl is no longer officially registered for thinning apples. Thus, another agent for thinning ‘Elstar’ and other apple cultivars is urgently needed. This paper reports on two trials made with the thinning agent MaxCel containing 6-benzyladenine (BA) as the active ingredient. Generally, MaxCel applied at 10-12 mm fruit diameter thinned well, yielded bigger fruits and improved return bloom. However, thinning efficacy of MaxCel was negligible for weak growing trees or branches and increased with the vigour of the tree or branch. Adequate thinning and target fruit sizes were obtained with BA-concentrations in between 100 and 300 mg L-1 active ingredient. Results of thinning on pack-out and fruit quality are also presented.

Water spray as a potential thinning agent for date palm flowers (Phoenix dactylifera L.) c.v. ‘Lulu’

Flower or fruit thinning is a critical cultural practice in the date palm production chain that affects fruit development, quality and yield and regulates tree yearly bearing. Development of a save and economic thinning agent for date palm is critically required especially under harsh conditions. During 2004 and 2005 seasons, water spray for 3 min was applied at different times following mechanical pollination on ‘Lulu’ date palm cultivar growing under Al-Ain oasis conditions. The results showed that water spray following pollination generally decreased fruit set percentage to different extent depending of the time of application. In this respect, the most effective treatment was water spray after 4 h following pollination. This treatment significantly decreased fruit set percentage (48%) compared to the control (79%), as the mean of both seasons. However, the other treatments including water spray 1 h before pollination also decreased fruit set percentage but to a lesser extent. Fruit quality characteristics especially fruit and flesh weight, length and diameter were significantly increased by water spray treatments during the 2004 season, in contrast to the 2005 season. Thinning with water significantly decreased both bunch weight and total yield per tree at the Tamr stage especially when applied after 4 h following pollination. To the best of our knowledge, this is a pioneer study investigating the role of water as a potential thinning agent for date palm flowers. The use of water spray as a save and economic thinner needs, however, more research work to justify the time following pollination and duration of application which may vary upon cultivar, method of pollination and district.

Chemical Blossom Thinining on Prunus in New York

In 2004, we conducted a chemical thinning field study in Appleton, N.Y., on 5-year-old `Rising Star' peach trees on Lovell rootstock. Treatments included soybean oil or petroleum oil applied at 8% about 30 days before budbreak. Ammonium thio-sulfate (ATS) 3.5 gal/acre, ATS 5.0 gal/acre, lime sulfur (1%, 3%) plus Crockers fish oil 2 gal/acre, and Wilthin 6 pt/acre were applied at FB; and the grower standard hand-thinning treatment at 45 DAFB. Trees treated with thinning agents were not given supplemental hand thinning. The high rate of ATS, 5.0 gal/acre and Wilthin 6 pt/acre had the greatest thinning effect and reduced fruit set by 55% and 61%, respectively, compared to the untreated control. The high rate of ATS also increased fruit size 25%, but reduced yield by 45%. Soybean and petroleum oil treatments did not significantly reduce fruit set. Lime sulfur plus fish oil treatments 1% and 3% also did not significantly reduce fruit set. Although a significant reduction in yield was observed in the high rate ATS and Wilthin treatments, a greater proportion of the crop was in the larger size categories. In 2005, treatments included soybean oil 8% plus Latron B 1956 applied 18 days and 25 days before FB, Lime sulfur (2%, 4%) plus Crockers fish oil (2%) applied at FB, Ammonium thio-sulfate (ATS) 3.5%, 5.0%, Wilthin 1.9, 2.8 L (Entek, Inc.), plus Regulaid 473 mL per 935 L/ha applied at FB, Entry 1.5, 3.0%, Tergitol TMN-6 0.75, 1.5%, hand-thin flowers to a crop load of seven fruits per cm2 at FB and hand-thin fruit to 7 fruits per cm2 applied 45 days after FB.

Fish Oil Plus Lime Sulfur Shows Potential as a Sweet Cherry Postbloom Thinning Agent

Received for publication 8 Feb. 2006. Accepted for publication 7 Mar. 2006. We are grateful to David Ophardt for technical assistance, James McFerson, Don Elfving, and Preston Andrews for their critical manuscript reviews, and to the WSU Agricultural Research Center and the Washington Tree Fruit Research Commission for financial support. Author to whom reprint requests should be addressed; e-mail mdwhiting@wsu.edu. Fish Oil Plus Lime Sulfur Shows Potential as a Sweet Cherry Postbloom Thinning Agent Olivia M. Lenahan and Matthew D. Whiting Washington State University, Irrigated Agriculture Research and Extension Center, 24106 North Bunn Road, Prosser, WA 99350

Effects of Lime Sulfur and Fish Oil on Pollen Tube Growth, Leaf Photosynthesis and Fruit Set in Apple

The effect of liquid lime sulfur (LS) and fish oil (FO) application during bloom on leaf photosynthesis (Pn) and pollen tube growth in apple (Malus ×domestica) flowers were investigated in order to determine their mode of action as a bloom thinning agent. LS increased the percentage of flowers with fewer than 10 pollen tubes per flower to more than 64% compared to 5% or less in the control. Pollen tubes were completely absent from 27% to 48% of flowers following LS treatment compared with fewer than 4% of flowers having no pollen tubes on control trees. These data indicate that 30% to 50% of flowers that open on the day of LS application are unlikely to set a fruit due to the complete inhibition of embryo fertilization. Increasing the rate of LS from 0.5% to 4% increased the proportion of flowers with limited pollen tube number in a concentration dependent manner. LS suppressed the rate of light saturated Pn; successive LS sprays during the bloom period had an additive effect on suppression of Pn and fruit set. In one study the reduction in Pn was greatest 12 days after application of LS but Pn recovered by about 19 days after initial treatment. In a second study Pn of primary spur leaves had still not recovered when measured 57 days after the first of three applications. FO had no effect on the number of pollen tubes per flower, but reduced Pn and fruit set by about 10% and 20% respectively. An increase in the proportion of flowers with no pollen tubes, and therefore no embryo development, can account, at least in part, for the thinning response following application of LS to apples during bloom. It is likely that suppression of Pn contributes to the thinning response, although the importance of this mechanism will depend on perturbation of the total carbohydrate supply to developing fruit.

64: Abnormal Uterine Bleeding and Quality of Life Measures after Microwave Endometrial Ablation

Study ObjectiveTo assess improvement in abnormal uterine bleeding and quality of life measures after microwave endometrial ablations performed at Duke University.DesignRetrospective analysis of consecutive cases of microwave endometrial ablation.SettingAn academic or tertiary clinic setting.PatientsTwenty-three females who underwent microwave endometrial ablation from November, 2003 through April, 2005. The vast majority of females had been referred to our clinic after failing medical therapies.InterventionMicrowave endometrial ablation in an ambulatory surgical setting.Measurements and Main ResultsData to be presented includes improvement in abnormal uterine bleeding and quality of life measures. Only 1 of 23 (4%) females failed or was unsatisfied with the MEA procedure. Those females who received pre-operative endometrial thinning agents had overall improved outcomes compared to those females who did not. One female with large myomas underwent MEA prior to uterine artery embolization, and at 3 month follow-up had a reduction from 14 days of bleeding to 3 days of bleeding.ConclusionMicrowave endometrial ablation provides an effective alternative to hysterectomy for females that fail medical management. Study ObjectiveTo assess improvement in abnormal uterine bleeding and quality of life measures after microwave endometrial ablations performed at Duke University. To assess improvement in abnormal uterine bleeding and quality of life measures after microwave endometrial ablations performed at Duke University. DesignRetrospective analysis of consecutive cases of microwave endometrial ablation. Retrospective analysis of consecutive cases of microwave endometrial ablation. SettingAn academic or tertiary clinic setting. An academic or tertiary clinic setting. PatientsTwenty-three females who underwent microwave endometrial ablation from November, 2003 through April, 2005. The vast majority of females had been referred to our clinic after failing medical therapies. Twenty-three females who underwent microwave endometrial ablation from November, 2003 through April, 2005. The vast majority of females had been referred to our clinic after failing medical therapies. InterventionMicrowave endometrial ablation in an ambulatory surgical setting. Microwave endometrial ablation in an ambulatory surgical setting. Measurements and Main ResultsData to be presented includes improvement in abnormal uterine bleeding and quality of life measures. Only 1 of 23 (4%) females failed or was unsatisfied with the MEA procedure. Those females who received pre-operative endometrial thinning agents had overall improved outcomes compared to those females who did not. One female with large myomas underwent MEA prior to uterine artery embolization, and at 3 month follow-up had a reduction from 14 days of bleeding to 3 days of bleeding. Data to be presented includes improvement in abnormal uterine bleeding and quality of life measures. Only 1 of 23 (4%) females failed or was unsatisfied with the MEA procedure. Those females who received pre-operative endometrial thinning agents had overall improved outcomes compared to those females who did not. One female with large myomas underwent MEA prior to uterine artery embolization, and at 3 month follow-up had a reduction from 14 days of bleeding to 3 days of bleeding. ConclusionMicrowave endometrial ablation provides an effective alternative to hysterectomy for females that fail medical management. Microwave endometrial ablation provides an effective alternative to hysterectomy for females that fail medical management.

Thinning of ’Golden Delicious’ apples with the combination of ethephon and CPPU

A synthetic cytokinin forchlorfenuron (CPPU) 5 ppm was sprayed at the time of petal fall (PF) on eight years old ’Golden Delicious’/M.9 apple trees with the aim of enlarging the fruit growth. Since CPPU is not recognized as a thinning agent which increases the return bloom, a low dose of ethephon was sprayed on CPPU treated trees to enhance flower bud formation and increase flowering in the next season. Ethephon was applied in successive treatments (alone or in the combination with CPPU) 3 x 30 ppm or 5 x 50 ppm, starting at PF, and continued in week intervals. The single application of CPPU 5 ppm or the combination of ethephon 3 x 30 ppm with CPPU 5 ppm decreased the fruit set and enhanced the fruit growth to reach the commercial demand. The combination spraying of ethephon 5 x 50 ppm + CPPU 2 x 5 ppm resulted in a too strong thinning response while the yield of bigger size fruit was not enhanced. Thealone application of ethephon 3 x 30 ppm had no influence on the fruit thinning or fruit weight while the application ofethephon 5 x 50 ppm reduced the fruit set but, consequently, did not enhance the fruit growth. None of the treatments influenced the return bloom.

TESTING POTENTIAL ALTERNATE METHODS OF BLOOM THINNING FOR APPLE IN VITRO

Alternate bloom thinners are needed for apple are needed to replace compounds which can no longer be used or have production system limitations. The effects of 24 chemicals selected as osmotic agents, organic acids, oils, essential oils, or potential metabolic agents and their properties of pH, electrical potential (EP) and water potential were tested in vitro on `Gala' apple pollen germination, tube growth and pistil damage. Solution concentrations of 0%, 0.25%, 0.5%, 1%, 2%, 5%, and 10% were prepared and solution pH, EP, and water potential measured. To test affects on germination, pollen was placed on agar germination media in petri dishes and then treated with 10: l of chemical solution. Percentage pollen germination and tube growth was calculated 4, 12, and 24 h after treatment. Excised pistils from forced flowers were placed on glass filter papers saturated with chemical solution. Pistil damage was visually, subjectively rated for damage indicated by discoloration 24 h after treatment. Effects of solution pH, EP and water potential on pollen germination, tube growth and pistil damage was significant with pH less than ∂4.0 or greater than ∂10.0, EP > 200mv, or water potential less than ∼4.0MPa inhibited pollen germination, growth, and killed pistils. Several chemical had apparent metabolic effects beyond the chemical effects mentioned above. In vitro tests were correlated to in vivo field tests in other studies indicating the use of pollen and pistil in vitro as a useful model for screening potential alternative thinning agents.

EFFECTS OF VARIOUS ACID COMPOUNDS ON CO2 ASSIMILATION, EVAPOTRANSPIRATION, AND STOMATAL CONDUCTANCE OF APPLE

Alternative fruit thinners and pesticides are needed for certified organic fruit growers. A transient reduction in photosynthesis has proven to be an effective technique used for fruit thinning. Conversely, pesticides, which reduce Pn may be detrimental to plant growth. This study was developed to measure plant response to foliar applications of various organic acids as potential horticultural chemicals Treatments were applied to vegetative apple trees under controlled environmental conditions to study photosynthetic effects. CO2 assimilation significantly decreased temporarily 3 days after treatment with citric acid. Decreased trends of evapotranspiration were observed for all treatments 1 day after foliar application; however, not significant. Salicylic acid significantly decreased stomatal conductance 1 and 15 days after treatment. Average leaf area was not significantly affected but oxalic acid increased plant stem growth while acetic acid application reduced growth. This model system for screening new and alternative compounds will be a basis to study agents that may have potential to be used as certified pesticides or fruit thinning agents.

EFFECT OF 6-BA AND NAA AS THINNING AGENTS OF ‘CONFERENCE’ PEAR

EFFECT OF 6-BA AND NAA AS THINNING AGENTS OF ‘CONFERENCE’ PEAR

Effect of blossom stage of ‘Alpine’ nectarine on efficacy of chemical thinning using Armothin

Fruit thinning of peach and nectarine cultivars is essential to maximize profitability and stabilize production and is routinely done by hand thinning of blossoms and early fruit. Chemical thinning of blossoms may reduce the cost of manual labour, but results are inconsistent and commercialization is lacking. Blossom sensitivity to caustic agents may depend on blossom type and degree of pollination and/or fertilization. Armothin®, a registered blossom thinning agent, was evaluated at 1.5% v/v and 3% v/v applied at 11, 17 and 42% full-bloom, to evaluate the effect of blossom type and the fertilization and/or pollination of blossoms, on thinning of ‘Alpine’ nectarine. The earliest application (11% full-bloom) of 3% v/v Armothin® provided optimum thinning and fruit size. Any blossoms showing pink appear to be removed by Armothin®, while open blossoms are removed irrespective of whether they are fertilised and/or pollinated. The removal of early opening blossoms results in the potential loss in early ripening, higher value fruit especially in an early cultivar. Later maturing blossoms remain to develop into later maturing fruit which tend to be smaller. Thus an early application of 3% Armothin®, when less than 50% blossoms show pink, may provide sufficient blossom thinning to expedite later hand thinning, but does not necessarily remove the need for hand thinning.

Tergitol TMN-6 for Thinning Peach Blossoms

This study was conducted to determine efficacy of Tergitol TMN-6 in thinning peach blossoms. A pretest was conducted and demonstrated no difference between TMN-6 and TMN-10 in efficacy when applied at full bloom or petal fall and at rates of 20 and 40 mL·L-1. In the main test, Tergitol TMN-6 was sprayed once at 10, 20, or 30 mL·L-1 at full bloom or petal fall and compared to an unsprayed control for 3 years. Tergitol caused widespread necrosis of flower parts including sepals, petals, pistils, stamens and peduncles. There was a difference among chemical treatments with more fruit removed at higher concentrations, although the amount of fruit removed was similar for the 20 and 30 mL·L-1 rates. There was no difference in thinning response at full bloom or petal fall, indicating a wide window of efficacy. There was also a difference among years, which was apparently not related to temperature or relative humidity during time of application. Tergitol caused some leaf yellowing and tip burn especially at the higher rates when leaves were present, but the trees did not appear to be seriously affected. Fruit weight was either not affected or larger in some years from treatment. Unlike higher concentrations, tergitol at 10 mL·L-1 did not negatively impact fruit number per tree at harvest. At harvest, fruit weight, skin blush, firmness, and soluble solids at harvest were not affected by treatment. Tergitol TMN-6 proved to be an effective thinning agent and when applied from full bloom to petal fall at 10 mL·L-1 it did not adversely affect the tree or fruit.

PHOTOSYNTHETIC INHIBITION OF 'SEYVAL BLANC' GRAPEVINES WITH TERBACIL

PHOTOSYNTHETIC INHIBITION OF 'SEYVAL BLANC' GRAPEVINES WITH TERBACIL

Thinning and Plasticization of HCBS (Highly Concentrated Ceramic Binding Suspension) Based on High-Alumina Chamotte

HCBS (highly concentrated ceramic binding suspensions) based on a high-alumina chamotte (75.5% Al2O3) with a volume concentration CV = 0.73 is prepared by the wet grinding technique. The effect of a complex organomineral thinner on the rheological properties of HCBS (with and without refractory clay added) has been studied. Adding a 0.02% thinning agent composed of 75% sodium tripolyphosphate and 25% SB-5-grade superplasticizer results in a substantial decrease in viscosity of the systems studied.

Dispersing (Deflocculating) Aluminas

The rheological properties of aqueous suspensions of a reactive alumina and high-alumina cements have been studied, and a method for evaluating the thinning effect due to agents used to deflocculate ceramic casting systems has been developed; a classification of thinning agents is proposed. Alumina dispersants make it possible to decrease the moisture content of Al2O3 suspensions by 50 – 60 rel.% and increase their volume concentration from 0.50 to 0.65. The characteristics of dispersing aluminas used for the thinning (deflocculation) of new refractory castables containing Al2O3 (76 – 96%) and organic deflocculants are given. Suspensions based on four types of dispersants (with a moisture content of 19 – 25%) exhibiting a thixotropic flow behavior are considered.

Effect of Thinning Agents on Properties of High-Alumina Ceramic Castables

The effect of thinning agents on molding mixtures for the production of high-alumina ceramic castables composed of bauxite HCBS (highly concentrated ceramic binding suspensions) and a refractory filler based on fused corundum and SiC is studied. The thinners used were sodium tripolyphosphate (STPP), SB-5-grade organic plasticizer, mixtures thereof, and liquid glass. The maximum thinning effect is observed for complex organomineral additives (10 – 33% SB-5 + 67 – 90% STPP). The optimum thinner concentration is 0.08 – 0.1 wt.%. The use of thinners makes it possible to reduce significantly the water demand of concrete mixes and leads to a decrease in porosity and an increase in strength of ceramic castables. The composition and concentration of alkali-containing thinners produce little (if any) effect on the deformation behavior of ceramic castables at high temperatures.

Flow Properties of Majolica Slip with a Thinning Additive Based on Sodium Polyacrylate

The effect of a new thinning agent, namely 40% sodium polyacrylate (SPA), on flow properties of majolica slip and the effect of hardness of water on changes in suspension moisture are considered. The use of 40% SPA makes it possible to reduce its content in slip by nearly half, compared to sodium silicate solution, to improve the slip flow properties, and to insignificantly decrease its moisture. An optimum content of 40% SPA in thinning a polymineral clay slip from the Gzhel'skoe deposit and a majolica mixture is determined.

The Effect of Thinning Agents on Rheological and Technological Properties of the Bauxite HCBS System

The thinning effect (deflocculation) in wet-ground highly concentrated composite suspensions (90% bauxite + 10% quartz glass) is studied. The thinning agents used are sodium tripolyphosphate, SB-5 organic plasticizer, and mixtures thereof. Maximum thinning effect is attained with a composite organic mineral additive (20 – 35% SB-5 + 65 – 80% sodium tripolyphosphate). Optimum concentration of the additive is found to be 0.08 – 0.1%, or 0.4 – 0.5 mg/m2 solid-phase surface. At optimum composition and additive concentration, the thixotropic dilatant flow regime of HCBS changes to a dilatant flow regime with a sharp decrease in viscosity and an increase in density of cast preforms. A mechanism for the thinning effect due to additives is considered.

Pre-operative endometrial thinning agents before hysteroscopic surgery for heavy menstrual bleeding.

Menorrhagia is one of the most common reasons for pre-menopausal women to be referred to a gynaecologist. Although medical therapy is generally the first approach, many will eventually require or request a hysterectomy. Hysterectomy is associated with a significant in-patient hospital stay and a period of convalescence that makes it an unattractive and unnecessarily invasive option for many women. Hysteroscopic endometrial ablation or resection offers a day-case surgical alternative to hysterectomy for these women. It is also a cheaper procedure than hysterectomy. Complete endometrial removal or destruction is one of the most important determinants of treatment success. Therefore surgery will be most effective if undertaken when endometrial thickness is less than 4mm, in the immediate post-menstrual phase, however there are often difficulties in reliably arranging surgery for this time. The other option is the use of hormonal agents which induce endometrial thinning or atrophy prior to surgery. The most commonly evaluated agents have been goserelin (a GnRH analogue) and danazol. Progestogens and other GnRH analogues have also been studied although less data are available. It has been suggested that the use of these agents, particularly GnRH analogues, will reduce operating time, improve the intra-uterine operating environment, and reduce distension medium absorption (this is the fluid used to distend the uterine cavity during surgery). To investigate the effectiveness of gonadotrophin-releasing hormone (GnRH) analogues, danazol, and progestogens, when used for endometrial thinning prior to hysteroscopic surgery for menorrhagia, in improving the intra-uterine operating environment and treatment outcome after surgery. The Menstrual Disorders and Subfertility Group search strategy (see Review Group details) was used to identify randomised trials that had compared the use of these drugs with either each other, or placebo, or no pre-operative treatment. Trials were included if they compared the effects of these agents with each other, or with placebo or no treatment on relevant intra-operative and post-operative treatment outcomes. Only randomised studies were included in this review. Eight studies met the inclusion criteria for this review. Four studies compared goserelin (a GnRH analogue) with no treatment or placebo. Three studies compared goserelin with danazol. One study compared progestogens, danazol and triptorelin (a GnRH analogue) with no treatment. Data was extracted independently by two reviewers. A third reviewer checked data extraction for accuracy and wrote to authors where relevant data was missing or unclear. Intra-operative parameters included endometrial thickness, duration of surgery, ease of surgery, distension medium absorption and complication rate. Post-operative outcomes compared were the proportion of women with amenorrhoea, post-operative menstrual loss and dysmenorrhoea, and the need for further surgery. Data on side-effects were also recorded. When compared with no treatment GnRH analogues are associated with a shorter duration of surgery, greater ease of surgery and a higher rate of post-operative amenorrhoea. Post-operative dysmenorrhoea also appears to be reduced. The use of GnRH analogues has no effect on intra-operative complication rates and patient satisfaction with this surgery is high irrespective of the use of any pre-operative endometrial thinning agent. GnRH analogues produce more consistent endometrial atrophy than danazol. For other intra-operative and post-operative outcomes any differences are minimal. Both GnRH analogues and danazol produce side-effects in a significant proportion of women, though few studies have reported these in detail. Little randomised data is available to assess the effectiveness of progestogens as endometrial thinning agents and the effect of any thinning agent