Percentage Depletion Research Articles

Novel fluorinated pyrazolo[1,5-a]pyrimidines: In a way from synthesis and docking studies to biological evaluation

Starting compound 2-cyanomethyl-7-(thiophen-2-yl)-5-trifluoromethylpyrazolo[1,5-a]pyrimidine-3-carbonitrile 3 reacts with aromatic aldehydes, aromatic diazonium salts, o-hydroxybenzaldehyde and isatin, a series of new fluorinated pyrazolo[1,5-a]pyrimidine derivatives were obtained. Additionally, the enamine derivative of compound 3 reacts with each of hydrazine hydrate and guanidine hydrochloride to form fluorinated ployheterocycles. The newly synthesized compounds were characterized by spectral data (IR, 1H NMR, 13C NMR and MS) and elemental analyses. Some selected compounds were tested in vitro for antiviral activity against Coxsackie virus B4(COX-B4), Rift Valley Fever (RVF), Vesicular stomatitis virus (VSV), and Encephalomyocarditis (EMCV) virus. The results of the antiviral evaluation of some new compounds 3, 5c, 5i, 7b, and 15 showed good antiviral activity against the tested viruses, for example compound 5c containing the withdrawing group (Cl) showed 26.6% inhibition against COX-B4, while 5i containing the furan moiety showed decreased activity compared to 5c (21%). Furthermore, compound 15 which is a fused compound showed an inhibitory effect 23%. Also, compounds 3, 5c, 5i, 7b and 15 were evaluated against the HCV-NS3 protease using Sovaldi as a control. The results showed that compound 5c had a good inhibitory effect on hepatitis C virus protease (HCV-NS3), with an IC50 of 7.33 ± 0.51 μg/ml, compared to IC50 of Sovaldi 3.20 ± 1.33 μg/ml. The virucidal activity of 5c was also determined by direct and indirect methods. The direct method showed moderate antiviral activity (0.76 log(10) / ml, corresponding to the percentage depletion of the virus infectivity titer of 13.8%. In contrast, the indirect method showed better antiviral activity, which was dependent on the time of application (1.75 log (10) /ml), which is 31.828%. Molecular Operating Environment software (MOE, 2015.10) was used to dock compounds 3, 5c, 15 compared to Sovaldi as a reference drug with the active site of co-crystallized B-Raf (PDB code: 3II5). The results showed good formation of hydrogen bonds between the functional groups NH, CO, CN, S atom and N atom of the target compounds with His 573, Thr 528, Cys 531, Glu 500, lle 591, Asp 593 and Gly 595 residues in terms of bond length and binding energy compared to Sovaldi. In addition, Absorption Metabolism Distribution Excretion studies (ADME) are used in the drug development process to study various factors that influence drug action and efficacy. Thus ADME was performed for compounds 3, 5c and 15 and showed that compound 3 could be absorbed through the gastrointestinal tract compared to other compounds tested.

Systematic evaluation of species-independent serum pre-fractionation strategies revealed cost-effective methods to reduce proteome complexity

In this study, the efficiency of one commercial (ProteoMiner™ -PM) and five simple and cost-effective laboratory chemicals (Acetone, TCA/acetone, DTT, ACN and DTT-ACN) based serum protein pre-fractionation strategies was compared in pig model by label-free quantitation based mass spectrometric approach to find out the most suitable strategy for reducing the complexity of serum proteome for subsequent proteomic studies. The highest serum protein depletion percentage and highest depletion of albumin, the most abundant serum protein, was observed in DTT-ACN method. The maximum number of serum proteins was identified in ACN followed by DTT-ACN method and importantly, detection of more number of low-abundant proteins (LAPs) could also be achieved by these two methods. Although PM method resulted into lowest dynamic range of protein abundance, quite a less number of proteins were identified by this method. Overall, sequential depletion using DTT-ACN and ACN methods provided advantage of simultaneous detection of more number of proteins along with LAPs with a reasonably high dynamic range of protein abundances over other methods and thus emerged as cheaper and effective alternatives to the commercial methods. Further, these methods are species-independent and hence can be applied in human and in any livestock species to simplify the serum proteome.

CD3, CD4, CD8, CD19 and CD16/CD56 positive cells in tuberculosis infection and disease: Peculiar features in children.

Pathogenesis of mycobacterial infection has been extensively studied determining the fundamental role of host immunocompetence in disease progression. Cellular adaptive immunity, in particular CD4+ cells, has shown to be crucial in the host defence. A role of cytotoxic lymphocytes and humoral immunity has also been established. However, few studies have been performed in low endemic countries on immunological correlates of tuberculosis in paediatric patients. The present study aims to fill this gap analysing the distribution and the absolute values of the main lymphocyte subpopulations (CD3+, CD4+, CD8+, CD19+ and CD16+/CD56+) in the different stages of tubercular infection in human immunodeficiency virus–negative children living in low tubercular endemic countries. Results obtained in children with latent tuberculosis, active tuberculosis and healthy controls were compared. Moreover, quantitative analysis of interferon-γ levels of mitogen-induced response was carried out within the different study groups. The aim of this analysis was to enforce the comprehension of immune modifications subsequent to Mycobacterium tuberculosis infection. The major finding of our study was CD3+ and CD4+ absolute and percentage depletion in children with active tuberculosis versus healthy controls. Moreover, severe forms of active tuberculosis showed a marked reduction in the CD4+ percentage in the context of a systemic impairment which affects globally the absolute count of all peripheral lymphocyte subsets tested. A relative increase of natural killer cells was proved in infected patients, whereas no differences in B cells among the study groups were detected. Mitogen-induced interferon-γ levels were significantly higher in children with latent tuberculosis when compared to active tuberculosis and healthy controls, demonstrating effective immune activation in those patients able to control the infection.

How the removal of producer subsidies influences oil and gas extraction: A case study in the Gulf of Mexico

Since producer subsides can entail significant economic, fiscal, social and environmental costs, governments have been increasingly interested in removing them. Although many studies have been done on reducing consumer subsidies, subsidies to fossil fuel production are rarely discussed by scholars. This paper seeks to fill this void by developing an economic optimization model for oil and gas extraction to analyze the effects of producer subsidy removal. We forecast field-specific costs for exploration, development and production through constructing functions for the number of wells drilled and producing wells, production and economic limits. Various scenarios of phasing out producer subsidies in U.S. federal and state regulation on optimal production using field data from the Gulf of Mexico are simulated, including removing royalty relief, amortization of geological and geophysical costs, and percentage depletion. The results show that removal of producer subsidies reduces the optimal production rate and investors' net present value and increases government revenue, but the total effect is a cost of net social benefits. Changes in both the discount rate and oil price have positive effects on optimal production, but they exert opposite effects on producer benefits. Our research is helpful for policy-makers to regulate an efficient subsidy removal path.

There's No Business Like Oil Business: The Allure of Tax Sheltered Oil Income to Hollywood's Wealthy

Hollywood’s greatest stars did not only produce blockbusters, but were savvy businessmen who also produced oil gushers. These stars invested in oil interests in order to shelter a large part of their income from the rapidly rising income tax rates of the 1930s. The unique tax benefit they used was the percentage oil depletion allowance, part of the Revenue Act of 1926, which allowed an oil company to reduce its taxable income by 27 ½ percent. By the 1950s, many Hollywood individuals and corporations extensively invested in the oil business which made the allowance an important component of their financial portfolios. Meanwhile, rich oilmen were also attracted to Hollywood to capitalize on a big hit, or use the losses on a money losing movie to offset their taxable profits from oil. Thus, in the mid-twentieth century, the American oil industry and Hollywood formed a close, mutually reinforcing relationship, and one that academic historians have largely overlooked. After the 1973 oil shock, the percentage depletion allowance came under threat as it was repealed for major integrated oil companies. To protect the allowance for the non-integrated independent producers, Hollywood found their political patron in the famous Hollywood actor and Republican president, Ronald Reagan. As president, Reagan ardently defended the retention of the allowance during his term in the 1980s. Hollywood’s role in the oil industry developed from being a few casual investors using the oil depletion allowance into a substantial oil industry participant and a major political defender of oil-specific tax provisions.

A Maritime Lawyer, the Percentage Depletion Allowance, and the Joint Committee on Taxation

This year marks the 90th anniversary of both the percentage depletion allowance and the Joint Committee on Taxation. This essay relates the curious tale of Norman Beecher, a New York maritime lawyer with little background in energy, natural resources, or tax, who convinced Congress in 1918 to adopt a tax proposal that helped lead to both of these important features of the tax system eight years later. While Beecher’s idea ended up providing a major tax break for the oil and gas industry, this essay presents evidence that the source of the proposal was Beecher himself, and not the industry, as a result of his misunderstanding of the proposal’s tax effect. Since the conditions especially favorable to enactment of the proposal were very short-lived, this essay offers the intriguing possibility that but for Beecher (or his misunderstanding), the tax system might never have included percentage depletion or, conceivably, the Joint Committee.

A New Approach of Canopy Temperature based Irrigation Scheduling of Wheat in Humid Subtropical Climate of India

The aim of the study is to develop a new canopy temperature based index named plant stress index (PSI) as an irrigation schedule tool and to develop a relationship between soil water depletion and PSI at different threshold values for wheat crop in humid subtropical climate. The experiments were conducted in two growing seasons 2008–2009 and 2009–2010 in Roorkee, India. Irrigations were scheduled as and when PSI reached to 0.25 (T2), 0.5 (T3) and 0.75 (T4). Two treatments, one fully irrigated (T1) and one fully stressed (T5), were maintained to measure the reference minimum and maximum canopy temperatures. Canopy temperatures were measured with infrared radiometers. Soil moisture contents were measured with soil moisture sensors buried at 20 cm interval up to 100 cm. An automatic weather station was installed to measure the net radiation, wind speed, relative humidity and air temperature etc. concurrently at half an hour interval on the study field. To maintain PSI below corresponding threshold values, a total irrigation amount of 280, 252, 224, 214 and 50 mm during season 2008–2009 and 275, 240, 224, 201 and 50 mm during season 2009–2010 were applied in T1, T2, T3, T4 and T5 treatments, respectively. The experimental results gave an exponential relationship between percentage depletion of available soil moisture and threshold values of PSI. The results suggested that PSI may be maintained at 0.5 for getting optimum production of wheat. Corresponding to 0.5 PSI, the percentage depletion of available soil moisture was found to be approximately equal to 32 %.

EFFECT OF PHENTHOATE ON PROTEIN LEVELS OF FRESHWATER FISH LABEO ROHITA (HAMILTON)

The organophosphorus pesticide Phenthoate has been widely used in agriculture for several crops such as paddy, cotton and vegetables to control serious insects and mites in many areas of India. These chemicals cause severe damage to aquatic ecosystem especially to fishes. The main aim and objective of present study is to evaluate the impact on proteins metabolism in fingerlings of Labeo rohita an economically important Indian major carp. The lethal concentration was found to be 2.1mg/l under laboratory condition and 1/10 th of lethal concentration for 96hrs LC50 value is considered as sub lethal concentration. The exposure of fish to sub lethal concentration for 1, 4 and 8 days and investigated significant changes in the vital organs by following standard protocols. The results shows that the percentage of proteins degradation was minimum (7.62%) in gut and maximum percentage (11.76%) in liver for 1day, minimum reduction was (8.04 %) in brain and maximum was (13.64%) in liver for 4 days, minimum percentage depletion (8.36 %) in gill and maximum was (22.46%) in liver for 8 days compared to control. The total protein content levels rapidly induced might be due to the pesticide pollution and inhibition of metabolizing enzymes by toxicity. It is concluded that Phenthoate concentrations (low and high) is very toxic and causes alterations in vital organs of fish L. rohita.

Investigation of the sky optical conditions over selected stations in the major vegetation zones of Nigeria

Data-set of monthly global solar irradiance covering periods of at least 20 years over selected stations in Nigeria have been utilised to investigate the sky optical conditions over the five major vegetation zones of the country. The monthly variation of the clearness index for the selected stations has been investigated. Results show that the clearness index has its minimum in August which indicates reduced insolation during the monsoon month of August and maximum around November, December and February which shows high insolation. Statistical analysis of the monthly clearness index which gives the percentage depletion by the sky of the incoming insolation and the subsequent characterisation of the sky conditions based on this were also done. The results show that cloudy sky conditions prevail in the rainforest and mangrove swamp zones (e.g. Lagos, KT=0.40) while clear sky conditions prevail in the Sudan and Sahel vegetation (e.g. Nguru KT=0.66) and Kano (KT=0.65).

Chemical processes in sea-salt chloride depletion observed at a Canadian rural coastal site

Abstract Chloride depletion in sea-salt aerosols was studied using size-segregated inorganic ions data collected at a Canadian rural coastal site during a summer (June 29–July 15, 2002) and a fall campaign (October 25 – November 15, 2002). Three samples collected in the fall campaign had high concentrations of sea-salt and ammoniated sulfate and nitrate aerosols and were used to study the relative importance of different chemical reactions contributing to the depletion. The percentage depletion (Cl−depletion(%)) increased substantially with decreasing particle size (up to 86% for particles in the size range of 1.0–3.1 μm). For particles >6.2 μm, the observed NO3− was responsible for all the depleted Cl−; but less than a quarter of the depletion was explained by the HCl-released reaction between NaCl and HNO3; the rest of the depletion was likely due to the non-HCl-released reactions, e.g., between NaCl and N2O5. For particles in the size range of 3.1–6.2 μm, the NO3− was responsible for nearly 80–90% of all the depleted Cl− via HCl-released and/or non-HCl-released reactions; the remaining depletion was likely due to the reactions releasing Cl2, HOCl, etc. Particles >3.1 μm were mostly neutral acidity while a portion of particles at 1.0–3.1 μm was acidic. SO42− was only responsible for Cl−depletion(%) in acidic particles at 1.0–3.1 μm and the highest Cl−depletion(%) was observed in acidic particles of this size range.

The Performance of by Turns Fermentation- Dryer for Vanilla (Vanilla Planifolia Andrews) Processing

The drying and fermentation are the processing steps which influence the quality of vanilla. Thus, an effort to produce instrument which can dry and ferment vanilla by turns automatically was done. Based on the test result on the instrument, it was known that the heater and heat-exchanger can function excellently. It can be seen from the increase of temperature after passing heater and heat-exchanger; and the decrease of air humidity in the drying chamber. The small differences of air flow speed between racks proved the uniformity of air flow speed in the drying chamber. The time and temperature control system showed temperature stability on drying process (i.e. 60°C) and on fermentation process (i.e. 40°C); moreover, temperature response reached 60°C and did not exceed the setting time (maximum 30 minutes). The water percentage depletion from 88% to 55% is relatively slow (in 5 days fermentation-drying process). The depletion is appropriate with the recommendation for fermentation-drying vanilla processing.

Antioxidant activity of lees cell surface during sparkling wine sur lie aging

Given the importance of the interactions between wine and lees cell surface during sparkling wine aging, and in view of recent results proving the antioxidant potential of yeast cell wall biomolecules, the antioxidant capacity of lees cell surface was investigated to establish its possible role in the antioxidative effect of lees. The surface antioxidant activity of lees from wines with different aging periods was determined on the whole cell by two widely used methods (DPPH and FRAP assays), obtaining maximum values of 24.5 μmol Trolox/g cells (fresh weight) by the DPPH assay, and 21.3 μmol Trolox/g cells (fresh weight) by the FRAP assay. Lees surface antioxidant activity was influenced by base wine characteristics and inversely related to sur lie aging period. Conversely, the percentage depletion of lees surface antioxidant activity during aging was mainly determined by the length of aging, regardless of wine characteristics. To examine the influence of cell wall thiol groups and adsorbed polyphenols on lees' protective effect, their presence on cell surfaces was assessed. They accounted for 25 ± 11% and 54 ± 7% of the antioxidant activity measured by DPPH, respectively, and 0.3 ± 0.1% and 39 ± 8% measured by FRAP, respectively. Only a part of the remnant antioxidant activity of lees surface measured by FRAP could be theoretically explained by the presence of cell wall mannans.

America’s Hidden Power Bill: Examining Federal Energy Tax Expenditures

Tax expenditures — government spending programs that deliver subsidies through the tax code via special tax credits, deductions, exclusions, exemptions, and preferential rates — are the dominant type of federal support for the U.S. energy industry. Altogether, these spending programs amount to 60 percent of the government’s total support to the industry. These tax expenditures are functionally equivalent to direct spending, but they are often subject to less scrutiny. Viewing tax expenditures through the same lens as other government expenditures provides a clearer image of both how they support public policy and use public resources. This paper adopts that lens and looks at two energy-related tax expenditures: the percentage depletion allowance in the oil industry and the production tax credit, or PTC, in the wind industry. We also consider a program in which a tax expenditure was temporarily converted into direct spending: the cash grant in lieu of the investment tax credit, or ITC, for wind generation. Through this analysis, we find these tax expenditures lack accountability, transparency, and measurability, yet there is some indication that the wind-related expenditures are effective. We find little justification for the percentage-depletion allowance, but we do find that when tax expenditures are redesigned and offered as direct spending — as with the cash grant in lieu of the ITC — the program can be more effectively monitored and managed.

Development of crop water stress index of wheat crop for scheduling irrigation using infrared thermometry

This study was conducted to develop the relationship between canopy–air temperature difference and vapour pressure deficit for no stress condition of wheat crop (baseline equations), which was used to quantify crop water stress index (CWSI) to schedule irrigation in winter wheat crop ( Triticum aestivum L.). The randomized block design (RBD) was used to design the experimental layout with five levels of irrigation treatments based on the percentage depletion of available soil water (ASW) in the root zone. The maximum allowable depletion (MAD) of the available soil water (ASW) of 10, 40 and 60 per cent, fully wetted (no stress) and no irrigation (fully stressed) were maintained in the crop experiments. The lower (non-stressed) and upper (fully stressed) baselines were determined empirically from the canopy and ambient air temperature data obtained using infrared thermometry and vapour pressure deficit (VPD) under fully watered and maximum water stress crop, respectively. The canopy–air temperature difference and VPD resulted linear relationships and the slope ( m) and intercept ( c) for lower baseline of pre-heading and post-heading stages of wheat crop were found m = −1.7466, c = −1.2646 and m = −1.1141, c = −2.0827, respectively. The CWSI was determined by using the developed empirical equations for three irrigation schedules of different MAD of ASW. The established CWSI values can be used for monitoring plant water status and planning irrigation scheduling for wheat crop.

Effects of cycle strategy and fibre composition on muscle glycogen depletion pattern and subsequent running economy

PurposeIn this study, the effects of variable and constant-intensity cycling on muscle glycogen depletion patterns and subsequent running economy was examined. 60 minutes of cycling at a constant power (CON)...

Seasonal dynamics in the concentrations of macronutrients and organic constituents in green and senesced leaves of three agroforestry species in southern Ethiopia

Foliar inputs from indigenous agroforestry trees and shrubs could provide sufficient nutrients and organic matter to sustain crop growth. However, concentrations of foliar nutrients and organic constituents show considerable seasonal, inter- and/or intra-species variations. To determine this variability, green and senesced leaves were sampled during dry and wet seasons from Cordia africana, Albizia gummifera and Milletia ferruginea trees at Wondo Genet, southern Ethiopia. Cordia is a deciduous, non-leguminous tree, while Albizia and Milletia are semi-deciduous and leguminous trees. Leaves were analyzed for concentrations of ash, N, P, K, cellulose, lignin, soluble polyphenols, and condensed tannins. Results from statistical analyses showed significant seasonal variations (P < 0.001) in concentrations of all leaf constituents, except for P and cellulose. Foliar concentrations of ash, N, soluble polyphenols, and condensed tannins were higher during the wet season while those of K and lignin were higher during the dry season. Green leaves had significantly higher (p < 0.001) N and P concentrations than senesced leaves, while senesced leaves had higher concentrations of K, cellulose, soluble polyphenols, and condensed tannins. The ‘ Relative Percentage Changes’ in concentration of N and P in senesced leaves, i.e., their enrichment or depletion with such nutrients relative to those in green leaves, were significantly higher (P < 0.001) for Cordia than Albizia and Milletia. On the other hand, there was no consistent pattern in the enrichment or depletion of senesced leaves with organic constituents, but these leaves were in most cases more enriched with organic constituents than green leaves. Over all, the percentage depletion or enrichment ranged from about 8% to 38% for N; 24% to 63% for P; −141% to 48% for K; −44% to 15% for cellulose; −44% to 51% for lignin; −203% to −61% for soluble polyphenols; and −290% to 11% for condensed tannins. It was concluded that variations in species and life-form (legume versus non-legume), season, and developmental stage of leaves could affect the quality of organic material from agroforestry species, which has important implications for management of organic residues in tropical agricultural systems.

Analysis of sky conditions using solar radiation data over a tropical station

Radiation data in Nigeria are very sparse because radiation is not routinely measured. The data used for this work are from the physics Department of Obafemi Awolowo University, lle-lfe which is one of the few stations that collect radiation data in Nigeria. The daily, global and diffuse radiation measurements have been used to characterize the atmosphere of lle-lfe (70 14` N, 40 35` E) during January to December 1994. The clearness index ky (=H/H0) which gives the percentage depletion by the sky of the incoming global radiation and the relative sunshine (s/s0) gives the measure of cloud in the atmosphere has been adopted for use in this study. Also investigated are the diffuse radiation Kdiff (=Hdiff/H) and the diffuse coefficient Kcoef (= Hdiff/H0) that mirror the effectiveness of the sky in the scattering of the incoming radiation. Results show an average Kt value of 0.57 for year 1994 with maximum clearness index occurring in June (Kt= 0.68) and minimum in Dec (Kt =0.42). This present study also shows that the relative sunshine s/s0 has its minimum in August which indicates reduced hours of sunshine and solar insolation during the monsoon month of August in the tropical Nigeria station. Keywords: Daily, global and diffuse radiation, clearness index, diffuse coefficient, relative sunshine [Global Jnl Pure & Appl. Sci. Vol.9(3) 2003: 387-392]

Analysis of sky condition using solar radiation data at Kwangju and Seoul, South Korea and Ile-Ife, Nigeria

¶Daily global and diffuse radiation measurements have been used to characterize the atmosphere optical conditions at Kwangju (Lat.35.13N, Long.126.53E) and Seoul (Lat.37.57N, Long.126.98E) in South Korea and Ile-Ife (Lat.7.14N, Long.4.56E) in Nigeria. The clearness index, (CI) which gives the percentage depletion by the sky of the incoming global radiation and the diffuse ratio, (DR) which represents the effectiveness of the sky in scattering incoming radiation have been analyzed in this study. Results show an average clearness index value of 0.57 for the year 1999 with maximum values occurring during the wet seasons at Ile-Ife. The average clearness indexes for Kwangju and Seoul from 1998–2000 was 0.48 and 0.34, respectively, with both stations having maximum clearness indexes in the winter seasons. The diffuse ratio was higher at Kwangju and Seoul than at Ile-Ife due to heavy dust pollution from the Gobi desert in the Korea peninsula in spring, and high biomass burning at Kwangju in the fall.

The S-thiolation of hepatocellular protein thiols during diquat metabolism

The effects of diquat metabolism on the protein thiol (PrSH) status of ifbis-chloronitrosourea-pretreated hepatocytes bave been studied. Using a conventional, dithionitrobenzene-based assay for free PrSH in trichloroacetic acid-precipitated protein, control levels of PrSHs (83 ± 6 nmol/ mg protein) were unaltered during the initial 60 min of incubation of the cells with 1 mM diquat. However, using a radiochemical method for the determination of glutathionylation of PrSH [Grimm et al., Biochim Biophys Acta 844: 50–54, 1985], in which the hepatocytes were prepared from diethylmaleate-pretreated animals and reloaded with reduced glutathione (GSH) in the presence of [ 35S]methionine and cyclo-heximide, oxidation of hepatocellular PrSH by stimulated S-thiolation with GSH could be demonstrated. the S-glutathionylation of the protein was maximal after 30 min of treatment of the cells and preceded the onset of membrane leakage. However, the quantity of GSH mixed disulfide formed was limited to a maximum of if 1.4 ± 0.4 nmol GSH/mg protein, indicating the oxidation of oniy 2% of the total hepatocellular PrSH by S-thiolation. This percentage depletion is below the working variability of the colourimetric PrSH assay utilized and indicates strongly the use of the S-thiolation assay in the study of the possible effects of other redox-cycling cytotoxins on cellular PrSH status, as these may not be evident with conventional spectrophotometric techniques. the analysis of the cellular protein from diquat-treated cells by SDS-PAGE and autoradiography indicated the S-glutathionylation of a variety of cellular proteins, including species with molecular masses 17, 24, 26, 30, 40, 43 and 46 kDa. Although the identities of these species are uncertain (the 30-kDa protein may be equivalent to carbonic anhydrase as reported by Rokutan et al., Biochemistry 179: 233–239, 1989), it may be that oxidative modification of these proteins by stimulated S-glutathionylation may be an important early event in the mechanism of the hepatotoxicity of diquat.

Purification of functional lactotrophs and somatotrophs from female rats using fluorescence-activated cell sorting

As the secretory granules of anterior pituitary cells fuse with the cell surface, there would appear to be sufficient hormone present on the cell surface to be labelled by polyclonal hormone antibodies and thus analysed by flow cytometry. We have therefore applied fluorescence-activated cell sorting to these labelled pituitary cells. Percentage purity and depletion of other cell types was assessed by immunocytochemistry and the reverse haemolytic plaque assay (RHPA). Results demonstrate that fluorescence-activated cell sorting allows almost complete purification of functional lactotrophs and somatotrophs to 96.7 +/- 1.7 (S.E.M.)% and 98 +/- 1.0% respectively by immunocytochemistry, and to 95.8 +/- 1.1% and 97 +/- 0.8% respectively by RHPA. Depletion of other anterior pituitary cell types to less than 2% was demonstrated by both immunocytochemistry and RHPA. Fluorescence-activated cell sorting to this degree of purity was routinely possible with cell yields of 91 +/- 3.4%. To obtain such purity/depletion, it was necessary to use specific antisera of high titre, at concentrations which ensured maximal cell-surface labelling associated with maximal stimulation of hormonal secretion by the appropriate hypothalamic stimulatory factor. Separating cells on the basis of the intensity of prolactin cell-surface labelling demonstrated a low level of binding of the prolactin antibody to gonadotrophs (but not of sufficient fluorescence intensity to be sorted into the prolactin enriched population), raising the possibility of prolactin receptors on gonadotrophs. We were unable to demonstrate the presence of mammosomatotrophs in the normal female rat, since purified lactotrophs did not contain or secrete GH nor did purified somatotrophs contain or secrete prolactin.