Simultaneous determination of irinotecan (CPT-11) and SN-38 in tissue culture media and cancer cells by high performance liquid chromatography: Application to cellular metabolism and accumulation studies

A simple and sensitive HPLC method was developed to simultaneously determine CPT-11 and its major metabolite SN-38 in culture media and cell lysates. Camptothecin (CPT) was used as internal standard (I.S.). Compounds were eluted with acetonitrile–50 mM disodium hydrogen phosphate buffer containing 10 mM sodium 1-heptane-sulfonate, with the pH adjusted to 3.0 using 85% (w/v) orthophosphoric acid (27/73, v/v) by a Hyperclon ODS (C18) column (200 mm × 4.6 mm i.d.), with detection at excitation and emission wavelengths of 380 and 540 nm, respectively. The average extraction efficiencies were 96.9–108.3% for CPT-11 in culture media and 94.3–107.2% for CPT-11 in cell lysates; and 87.7–106.8% for SN-38 in culture media and 90.1–105.6% for SN-38 in cell lysates. Within- and between-day precision and accuracy varied from 0.1 to 10.3%. The limit of quantitation (precision and accuracy <20%) was 5.0 and 2.0 ng/ml for CPT-11 and 1.0 and 0.5 ng/ml for SN-38 in culture media and cell lysates, respectively. This method was successfully applied to quantitate the cellular accumulation and metabolism of CPT-11 and SN-38 in H4-II-E, a rat hepatoma cell line.

Synthesis and polymerization studies of 3-(+) and (-) -menthyl carboxylate pyrroles

The synthesis of 3-(−)- and 3-(+)-menthyl carboxylate pyrrole was achieved in four high yielding steps, including the triisopropylsilyl (TIPS) protection of the pyrrole nitrogen, bromination of the 3-position, lithium halogen exchange followed by reaction with menthyl chloroformate, and finally de-protection. Chemical polymerization of both the TIPS protected, and non-protected, menthyl carboxylate pyrroles was performed and the resulting polymers exhibited conductivity ranging from 0.6 to 2.3 S/cm. Polymerization of the 3-menthyl-N-TIPS pyrrole on the surface of wool was achieved by using solution and mist polymerization methods.

Significance of histological subtypes of Kikuchi`s disease: comparative immunohistochemical and apoptotic studies

Kikuchi's disease (KD) is a self-limiting lymphadenitis mostly affecting the cervical lymph nodes of young individuals. It has been classified into three histological subtypes and postulated to progress from the proliferative type (PT) to the necrotizing type (NT) and finally resolve into the xanthomatous type (XT). Since KD has been shown to be an apoptotic disease, the apoptotic activity was studied by the TUNEL method on 6, 12, and 6 cases of PT, NT, and XT, respectively, to see if the apoptotic activity could be shown to decrease in the order of the postulated sequence of evoluation. Significant statistical difference among the three subtypes was found (P = 0.050). Further analysis revealed that PT versus NT was significant (P = 0.010), but NT versus XT (P = 0.385) or PT versus XT (P = 0.310) was not. Analysis of three stages of NT was also significant (P = 0.019). Immunohistochemical study showed that abundant CD8+ T cells and cytotoxic protein positive cells were present in PT and NT, but were relatively low in XT. Our results showed progression of PT to NT, but not from NT to XT. Xanthomatous type was not the resolving stage of KD, but seemed to be a distinctive histological variant of KD caused by either different etiology or an unusual host reaction.

Contemporary philosophy and J.L. Shaw

Commemorative volume on Jaysankar Lal Shaw, b. 1939, Indian philosopher.

Fluorescence and conductivity studies on wool

An optimized synthetic method for the production of fluorescent conductive wool using pyrene, rhodamine B and fluorescein is reported. The application of fluorescent conductive polymers to wool was studied using solution and mist polymerization techniques. The effects of incorporating fluorescent dopants into the polymerization solution as well as the encapsulation of fluorescent dyes in a polypyrrole (PPy) micelle were also investigated. It was determined on the basis of both conductivity and fluorescence measurements that the encapsulation of dyes in PPy onto the surface of textiles gave the best results.

Investigations of the I Ching : II. Reliability and validity studies

In six studies on the I Ching - an ancient Chinese system of divination - successful predictions of first- and second-hexagrams (i.e., hexagram hitting) based on pre-selections of corresponding descriptor-pairs have ranged from chance, to significantly above chance. No significant effect below chance has ever been found. Hexagram hitting has been predicted by measures such as paranormal belief, time perspective, and meaningfulness. Storm (2008a) found a near-significant aggregate hexagram hit rate of 27%. Though these results are encouraging, there has been no assessment of the reliability and validity of the main test instrument used in the I Ching studies, the Hexagram Descriptor Form (HDF). To test the validity of the HDF, three control methods were tested against the experimental method. Taking first- and second-hexagram hit rates together, three out of 22 tests on the experimental method (14%) were significant or near-significant. Three significant or near-significant outcomes out of 66 control tests (4.5%) were attributed to chance. Inter-rater reliability was tested using two I Ching experts who judged the 64 descriptor-pairs of the HDF for suitability against their corresponding hexagram readings. The correlation between judges' ratings was not significant (the mean rating ranged between 60% and 82%). Using the pooled data of six studies, the HDF was tested for possible selection and outcome biases. A selection bias was found, but no outcome biases were found. The I Ching and the HDF were considered suitable for parapsychological research.