Effect of an anti-thyroid drug, 2,8-Dimercapto-6-hydroxy purine on reproduction in male rats

This histomorphological study is designed to evaluate the peripheral action of 2,8-Dimercapto-6-hydroxypurine (an antithyroid drug) on male reproductive system. The drug was administered as i.p. injection for 21 days to investigate its role on morphology of intratesticular cells and plasma testosterone level. Adult male rats (n=12), divided into three groups i.e. control, dimethylsulphoxide (DMSO) and 2,8-Dimercapto-6-hydroxypurine treated groups and treated with saline, DMSO and 2,8-Dimercapto-6-hydroxypurine for 21 consecutive days respectively. Blood samples were collected at day 1, 7, 14 and 21 and analyzed by using EIA systems. All the animals were scarified on 22nd day and testicular tissues were studied by histomorphpological assesment. 2,8-Dimercapto-6-hydroxypurine caused a significant decrease (P<0.0001) in mean testicular cell population, testicular cell diameter and resulted in arrested spermatogenesis. A significant decrease (P<0.0001) was observed in mean Sertoli and Leydig cell population and diameter in treated group. Similarly a significant decrease was observed in plasma testosterone levels at days 1, 7 and 14 (P<0.05) and further decrease by day 21 (P<0.01) of drug treatment. The present study suggests that 2,8-Dimercapto-6-hydroxypurine is a negative modulator of reproductive system as it suppressed the plasma testosterone level and proliferation of different testicular cell types in adult male rats.

2,3-Diaryl-2H-1-benzopyran derivatives interfere with classical and non-classical estrogen receptor signaling pathways, inhibit Akt activation and induce apoptosis in human endometrial cancer cells

OBJECTIVES

The present study was undertaken to explore the mechanism of anti-proliferative action of benzopyran compound D1 (2-[piperidinoethoxyphenyl]-3-phenyl-2H-benzopyran) and its hydroxy-(D2) and methoxy-(D3) derivatives in Ishikawa and human primary endometrial adenocarcinoma cells.

METHODS

Transcriptional activation assays were performed using luciferase reporter system and cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The stage of cell cycle was determined by flow-cytometry and real time analysis of cyclinE1 and cdc2 genes. The apoptotic effects were measured by AnnexinV/PI staining and TUNEL. The expression of PCNA, cyclinD1, pAkt, XIAP, cleaved caspase-9, -3, PARP, Bax and Bcl2 were determined by immunoblotting. The caspase-3 activity and mitochondrial membrane potential were measured by colorimetric assay.

RESULTS

All three compounds inhibited E(2)-induced ERE- and AP-1-mediated transactivation and proliferation in endometrial adenocarcinoma cells dose-dependently. Compound D1 caused the arrest of cells in the G(2) phase while D2 and D3 caused arrest in G(1) phase of the cell cycle. All compounds interfered with Akt activation, decreased XIAP expression leading to an increased cleavage of caspase-9, -3, PARP, increased Bax/Bcl2 ratio and caspase-3 activity.

CONCLUSION

Findings suggest that benzopyran derivatives inhibit cellular proliferation via modulating ER-dependent classical and non-classical signaling mechanisms, interfere with Akt activation and induce apoptosis via intrinsic pathway in endometrial adenocarcinoma cells.

Neutron activation analysis and atomic absorption spectrophotometry for the analysis of fresh, pasteurised and powder milk

This study shows the application of semi-absolute k 0 instrumental neutron activation analysis (k 0-INAA), epithermal neutron activation analysis (ENAA) and atomic absorption spectrophotometry (AAS) for the determination of 21 elements (Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sc Sr, and Zn) in different types of milk samples. The ENAA was required for the determination of iodine, AAS for Cu, Ni and Pb and the rest of the elements were measured by k 0-INAA. Thirteen elements (Br, Ca, Cl, Cs, Cu, Fe, K, Mg, Na, P, Rb, Sr and Zn) were identified in all milk samples. Ni was detected in eleven and Pb in two samples. Concentrations of most of the elements were within the ranges of the world reported data. The data was further explored by principal component analysis to find relationships between samples and elements.

6-Benzyl-sulfanyl-9H-purine

The phenyl ring of the title compound, C₁₂H₁₀N₄S, a purine derivative, is oriented at a dihedral angle of 76.65 (6)° with respect to the purine ring system. An inter­molecular N—H⋯N hydrogen bonds stabilizes the crystal structure.

Determination of natural radioactivity in building materials used in the Karachi area by γ-ray spectrometry and INAA

Samples of sand, stone and manufactured building materials collected from Karachi area have been analyzed for the primordial natural radionuclides 238U, 232Th and 40K using γ-ray spectrometry. The uranium and thorium contents have also been determined by instrumental neutron activation analysis (INAA). The specific activities in these materials, having a radium equivalent activity less than 370 Bq kg–1, when evaluated for radiological effects show that all materials meet the external γ-ray dose limitation of 1.5 mSv y–1. The γ-ray spectrometric and INAA techniques complemented each other well in this study.

Fission spectrum averaged cross section measurements of some neutron threshold reactions of relevance to medical radionuclide production

A resume is given of radiochemical measurements of nuclear reaction cross sections relevant to the production of some medically important radionuclides carried out at PINSTECH during the last decade. Systematic studies on fission neutron spectrum averaged cross sections of several threshold reactions, like (n, 2n), (n, p) and (n, α), on titanium, ruthenium, europium and dysprosium for the production of 45Ti, 96Tc, 153Sm and 153Gd are described.

Trace elements evaluation of some medicinal herbs by instrumental neutron activation analysis

Instrumental neutron activation analysis has been used for the analysis of seven varieties of medicinal herbs generally used by the people of South Asian region. Twenty-one trace elements (essential, toxic and non-essential) were determined. This data should not only be helpful in establishing the base-line values in these medicinal herbs but also in correlating their role as therapeutic agents. A comparison of our data with literature values shows variation in trace element contents of same species of different origin which can be attributed to ecological and geographical variations to some extent; however an exact interpretation demands further extensive investigations.

Measurement of fission neutron spectrum averaged cross sections of some threshold reactions on europium: small scale production of no-carrier-added153Sm in a nuclear reactor

Employing the activation technique in combination with radiochemical separations and high-resolution γ-ray spectroscopy fission neutron spectrum averaged cross sections were measured for several (n, 2n), (n, p) and (n, α) reactions on isotopes of europium. Our measurements constitute the first systematic studies. Of special interest was the investigation of153Eu(n, p)153Sm reaction for the production of no-carrier-added153Sm in a nuclear reactor. Using 100% enriched153Eu target, 97.21 MBq153Sm per batch can be produced which is, however, not sufficient for medical application.

Radiochemical neutron activation analysis of trace impurities in high purity titanium and tungsten

Rapid radiochemical neutron activation analysis (RNAA) procedures were developed and employed to the determination of 36 trace impurities in high purity titanium and tungsten. Anion–exchange column chromatography procedures were developed for the sequential group chemical separation of various elements, which helped in reducing the spectral interferences and improving the sensitivity of the method. The procedure is simple and requires a very short time to separate the elements in three groups for radiometric assay. To determine very low contents of uranium and thorium, 239Np and 233Pa as activation products were separated using anion–exchange and coprecipitation methods. The impurity contents were found to be low; therefore, their deleterious effects would be negligible.

Quantitative analysis of ancient Chinese ceramic using k 0-instrumental neutron activation analysis

IAEA-CU-2006-06 (ancient Chinese ceramic) has been analyzed by k 0-INAA and the results for 31 elements are reported. Measurement on Si was done via the (n,p) reaction. The results of 23 elements are within ±10% of the target values and for 2 elements data are reported as information values. The results produce lower relative deviation if compared with the mean reported concentration values submitted by the laboratories participating in the proficiency test. The analysis involves full peak efficiency calibration of the HPGe detector for all counting geometries and characterization of neutron flux at the irradiation channel by determining thermal to epithermal flux ratio and epithermal flux shape factor using Au and Zr flux monitors. The u-score is less than 1 for majority of the elements.

Fission neutron spectrum averaged cross sections of some threshold reactions on titanium: production feasibility of 45Ti in a nuclear reactor

Systematic studies on fission neutron spectrum averaged cross sections of some threshold reactions like (n, 2n), (n, p) and (n, α) on titanium were carried out using the activation technique in combination with radiochemical separations and high-resolution γ-ray spectroscopy. Special attention was paid to the formation 45Ti via the 46Ti(n, 2n)45Ti reaction since 45Ti labeled compounds are potentially important radiopharmaceuticals. At a fast flux neutron density of 7.5 × 1013 cm−2 s−1 and using 100% enriched 46Ti target, 8.58 MBq saturation activity of 45Ti per batch can be produced. Due to rather low activity and low specific activity the procedure is not feasible from medical application point of view.

Measurement of natural radioactivity and dose rate assessment of terrestrial gamma radiation in the soil of southern Punjab, Pakistan

Activity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs in soil samples collected from the most populous area of southern Punjab of Pakistan have been measured by gamma-ray spectrometry. The measured activity concentrations for these radionuclides are compared with the reported data from different other countries and it is found that measured activity concentrations are comparable with the worldwide measured average values reported by the UNSCEAR. Subsequently assessed radiological effects show that the mean radium equivalent activity (Ra(eq)) is 96.7 +/- 15.2 Bq kg(-1) and air absorbed dose rate (D) is 46.1 +/- 7.3 nGy h(-1). The values of internal and external radiation hazard indices are found to be less than unity. The annual effective radiation dose is calculated to be 0.28 +/- 0.05 mSv, which is well below the limit of 1.0 mSv y(-1) recommended by the International Commission on Radiological Protection, for the general public.

Measurement of natural radioactivity in bottled drinking water in Pakistan and consequent dose estimates

Natural radioactivity was determined in 11 different brands of commonly sold bottled drinking water in the federal capital Islamabad and Rawalpindi city of Pakistan using gamma spectrometry technique. Mean concentrations of 226Ra, 232Th and (40)K were found to be 11.3 +/- 2.3, 5.2 +/- 0.4 and 140.9 +/- 30.6 mBq l(-1), respectively. The annual cumulative effective doses due to all three natural radionuclides for different age groups of 1-5 y, 5-10 y, 10-15 y and adults (>or=18 y) were estimated to be 4.0, 3.4, 3.1 and 4.1 microSv y(-1), respectively. Among the three natural radionuclides, annual effective doses for all age groups from 226Ra were significant. Children in the age group of 1-5 y appeared to be at risk with respect to the annual effective doses from 226Ra as compared to the other age groups. Results obtained in this study are compared with the reported values from other countries of the world and it was observed that measured activity concentrations of three natural radionuclides in the bottled drinking water were lower than these values. Annual estimated effective doses for all four age groups from the intake of natural radionuclides in bottled drinking water were also found below the World Health Organisation (WHO) recommended limit of 0.1 mSv y(-1) as well as the average radiation dose of 0.29 mSv y(-1) received per head worldwide due to ingestion of natural radionuclides assessed by UNSCEAR (2000).

Determination of natural radioactivity in building materials used in the Rawalpindi/Islamabad area by gamma-ray spectrometry and instrumental neutron activation analysis

Samples of sand and manufactured building materials collected from the Rawalpindi/Islamabad area have been analyzed for the primordial natural radionuclides 238U, 232Th and 40K using gamma-ray spectrometry. The uranium and thorium contents have also been determined by instrumental neutron activation analysis (INAA). The specific activities of these radionuclides in the samples are compared with those of the world averages for soil. The comparison shows that, of the nine samples analyzed, only the three brick samples have higher activities than the world averages for soil. The specific activities in these materials, having a radium equivalent activity of less than 370 Bq kg-1, when evaluated for radiological effects show that all materials meet the external gamma-ray dose limitation of 1.5 mSv y-1. The gamma-spectrometric and INAA techniques complemented each other well in this study.

A spirostanol glycoside from Cestrum nocturnum

A new steroidal saponin named nocturnoside A has been isolated from the methanolic extract of the fresh leaves of Cestrum nocturnum and has been characterized by 13C NMR spectroscopy to be 3-O-[beta-D-glucopyranosyl(1----3)-beta-D-glucopyranosyl(1----2)-beta-D- glucopyranosyl((3----1)-beta-D-xylopyranosyl)(1----4)-beta-D- galactopyranosyl) (25R)-spirost-5-ene-2 alpha,3 beta-diol.