Higher hair nicotine level in children compared to mother living with smoking father in Malaysia.

OBJECTIVES: The objectives of this study are to determine parental and children's hair nicotine levels, their relationships as well as to investigate the association of smoking status of the fathers with mothers' and children's hair nicotine. METHODS: A cross-sectional study design was conducted among 124 families who were participants of the Universiti Sains Malaysia Pregnancy Cohort Study. Both parents with their 2 years old children joined this study. A total of 92 hair samples of fathers, 124 hair samples of mothers and 111 hair samples of children were collected and analyzed by gas chromatography-mass spectrometry. RESULTS: Of total, 52.4 % of the fathers reported smoking. None of the mothers were smokers. Hair nicotine levels of fathers were found to be significantly correlated with mothers (r = 0.233, p = 0.026) and children (r = 0.508, p < 0.001). Children living with smoking fathers had significantly higher median hair nicotine level compared to the children of non-smoking fathers (6.08 vs 0.22 ng/mg, p = 0.046). However, this association was not seen in the mothers. Quantile regression showed significant association between fathers' and children's hair nicotine. CONCLUSION: There is a positive relationship between fathers' hair nicotine with mother's and children's hair nicotine. Living with smoking fathers can contribute to higher hair nicotine levels in children but not in mothers.

Gamma irradiation increases the antioxidant properties of Tualang honey stored under different conditions.

This study was conducted to evaluate the effects of evaporation, gamma irradiation and temperature on the total polyphenols, flavonoids and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activities of Tualang honey samples (n = 14) following storage over three, six or twelve months. The mean polyphenol concentrations of the six gamma irradiated honey samples at three, six and twelve months, respectively, were 96.13%, 98.01% and 102.03% higher than the corresponding values of the eight non-gamma irradiated samples. Similarly, the mean values for flavonoids at three, six and twelve months were 111.52%, 114.81% and 110.04% higher, respectively, for the gamma irradiated samples. The mean values for DPPH radical-scavenging activities at three, six and twelve months were also 67.09%, 65.26% and 44.65% higher, respectively, for the gamma irradiated samples. These data indicate that all gamma irradiated honey samples had higher antioxidant potential following gamma irradiation, while evaporation and temperature had minor effects on antioxidant potential.

Chemical composition, antioxidant and cytotoxicity activities of the essential oils of Myristica fragrans and Morinda citrifolia.

BACKGROUND: In this study the chemical composition, antioxidant activities and cytotoxic effect of the essential oils of Myristica fragrans (nutmeg) and Morinda citrifolia (mengkudu) were determined. RESULTS: Thirty-eight compounds in nutmeg oil and six compounds in mengkudu oil were identified by gas chromatography­mass spectrometry. The free radical scavenging activity of nutmeg oil was superior of that mengkudu oil. The MTT assay of nutmeg oil on human colorectal carcinoma (HCT-116) and human breast carcinoma (MCF-7) cell lines showed IC50 values of 78.61 and 66.45 µg mL⁻¹, respectively. The mengkudu oil exhibited IC50 values of 91.46 and 78.15 µg mL⁻¹ for HCT-116 and MCF-7, respectively. CONCLUSION: The results showed that nutmeg oil can be developed as potent anti-cancer and antioxidant drugs.

Identification of thioketone analogues of sildenfil using gas chromatography-mass spectrometry.

Sildenafil analogues have been found adulterated in herbal preparations and food products that claim to have natural aphrodisiacs. In this study, a gas chromatography-mass spectrometry (GC-MS) assay was developed for the screening and identification of thioketone analogues of sildenafil. Thiopyrazolopyrimidine, a precursor or a cleavage product of thioketone analogue, exhibited characteristic fragment ions of m/z 328 and m/z 299 was found to be the best marker to screen the presence of general thioketone analogues. Identification by GC-MS assay was rapid and specific as all the studied thioketones showed characteristic mass fragmentations including their intact molecular ions. The developed GC-MS assay had successfully identified thiosildenafil, thiohomosildenafil and thiodimethylsildenafil in herbal preparation and food products.

Screening of tetrodotoxin in puffers using gas chromatography-mass spectrometry.

Tetrodotoxin (TTX), a toxic compound found in some puffers can cause death to humans through consumption. We have developed a simplified method for the screening of TTX in puffers using GC-MS. A puffer tissue of 0.5g was treated with 5mL of 0.1% acetic acid, followed by alkaline hydrolysis, LLE or liquid-liquid extraction and N-methyl-N-TMS-trifluoroacetamide derivatization. The developed method used only a small sample and solvent, simplified LLE and derivatization procedures and short chromatographic analysis (8.2min). All of these contribute to cost-saving, enhanced sample throughput and high sensitivity of the screening assay. The developed method was validated and proved to be within the acceptable range.

Identification of sildenafil, tadalafil and vardenafil by gas chromatography-mass spectrometry on short capillary column.

Sildenafil and its analogues (tadalafil and vardenafil) are phosphodiesterase type 5 inhibitors used in the treatment of male erectile dysfunction. Some dietary supplements, herbal preparations and food products which claim to enhance male sexual function have been found to be adulterated with these drugs. In this study, a gas chromatograph-mass spectrometer (GC-MS) assay was developed for identification of the drugs. In addition to good and short chromatographic separation that can be achieved within 6 min by using a short 10 m capillary column, no prior sample clean-up before GC-MS analysis was required, thus making this assay a cost saving and rapid method. Furthermore, the assay is specific as the identification of sildenafil, tadalafil and vardenafil were done by detection of molecular ions; m/z 474, 389 and 488, [corrected] respectively, and several other characteristic ions resulted from the mass fragmentation of individual molecules. Using our currently developed assay, sildenafil and its analogues were successfully identified in food and herbal matrices.

Determination of hair nicotine by gas chromatography-mass spectrometry.

Hair nicotine is a known biomarker for monitoring long-term environmental tobacco smoke (ETS) exposure and smoking status. In general, hair nicotine assay involves alkaline digestion, extraction and instrumental analysis. The gas chromatography-mass spectrometry (GC-MS) assay currently developed has shown to be of high throughput with average approximately 100 hair samples being extracted and analyzed per day. This was achieved through simplified extraction procedure and shortened GC analysis time. The extraction was improved by using small volume (0.4 mL) of organic solvent that does not require further evaporation and salting steps prior to GC-MS analysis. Furthermore, the amount of hair utilized in the extraction was very little (5 mg) while the sensitivity and selectivity of the assay is equal, if not better than other established methods. The linearity of the assay (r(2)>0.995), limit of quantitation (0.04 ng/mg hair), within- and between-assays accuracies and precisions (<11.4%) and mean recovery (92.6%) were within the acceptable range.

Correlation between urinary nicotine, cotinine and self-reported smoking status among educated young adults.

The objective of this study was to correlate, differentiate and validate the self-reported smoking status of educated young adults with urinary biomarkers (i.e. nicotine and cotinine). Freshmen students were recruited on voluntary basis. They filled-up self-administered questionnaire and their urine samples were collected for analysis. The urinary nicotine (UN) and cotinine (UC) were measured by gas chromatograph-mass spectrometry. Smokers, non-smokers and ex-smokers were found to be both significantly correlated and different in their UN and UC levels. UC level of 25ng/ml was the optimal cut-off to differentiate smokers from non-smokers. Using this cut-off value, the prevalence of smoking among the students was found to be higher (15.4%) than the self-reported data (14.3%). UC is useful in validating individual recent smoking history and the cut-off could serve as a marker for assessing the clinical impact of smoking and environmental tobacco smoke (ETS) exposure on human health.

Isolation, identification and quantification of differentially expressed proteins from cancerous and normal breast tissues.

BACKGROUND: Infiltrating ductal carcinoma (IDCA) is the most common type of breast cancer accounting for 85% of all invasive breast cancers. METHODS: Forty tissue specimens comprising 20 pairs of normal and cancerous tissues were analysed. The tissues were homogenized and proteins were extracted using phosphate buffer. The protein extracts from each pair of cancerous and normal tissue were separated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis in the same gel. The protein profiles of both the tissues were compared, and the differentially expressed proteins that were detected at >70% in one or both of the tissue types were selected for protein identification analysis. Target proteins were excised and digested in situ with trypsin prior to liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. A protein that was present in both tissue types was further quantified using extracted ions chromatogram. RESULTS: The proteins were grouped as down-regulated, up-regulated and unique proteins. Twenty-two proteins were identified and eight of the proteins were found unique to cancer. These proteins belong to various molecular classes, i.e. structural protein, hypothetical protein, cytoskeletal protein, enzyme, calcium binding protein and extracellular matrix protein. One extracellular matrix protein, namely collagen alpha-1(I) chain precursor was found unique to cancer. By virtue of its location on the cell surface and its function in cancer growth, this protein may be a biomarker candidate for breast cancer. CONCLUSIONS: The proteins identified in this study were present in at least 70% of the tissues tested; therefore they should have significant roles in the development of IDCA.

Simple, rapid and sensitive assay method for simultaneous quantification of urinary nicotine and cotinine using gas chromatography-mass spectrometry.

Nicotine is a major addictive compound in cigarette. Its smoke is rapidly and extensively metabolized to several metabolites in human. Cotinine as a major metabolite of nicotine is commonly used as a biomarker to determine active and passive smokers. Cotinine has a longer half-life ( approximately 20 h) compared to nicotine ( approximately 2h). A simple, sensitive, rapid and high throughput GC-MS method was developed for simultaneous quantification of urinary nicotine and cotinine in passive and active smokers. In the sample preparation method, the analytes and internal standard were first basified and followed by liquid-liquid extraction. Upon completion, anhydrous sodium sulphate was added to the solvent mixture to trap moistures. The clear extract obtained was directly injected into GC-MS, operating under selective ion monitoring (SIM) mode. Calibration curves in the range of 0.5-5000 ng/mL of the analytes in urine matrix were established with linear correlation coefficients (r(2)) greater than 0.997. The limit of detection for both nicotine and cotinine were 0.20 ng/mL. The mean recoveries for nicotine and cotinine were 93.0 and 100.4%, respectively. The within- and between-assay accuracies were between 2.1 and 7.9% for nicotine and between 0.7 and 11.1% for cotinine. Within- and between-assay precisions of 3.3-9.5% for nicotine and 3.4-9.8% for cotinine were also achieved. The method can be used in routine assessment and monitoring of active smoking and exposure to environmental tobacco smoke. The applicability of the assay was demonstrated in a small-scale comparison study between smokers and non-smokers.

Analysis of differentially expressed proteins in cancerous and normal colonic tissues.

AIM: To identify and analyze the differentially expressed proteins in normal and cancerous tissues of four patients suffering from colon cancer. METHODS: Colon tissues (normal and cancerous) were homogenized and the proteins were extracted using three protein extraction buffers. The extraction buffers were used in an orderly sequence of increasing extraction strength for proteins with hydrophobic properties. The protein extracts were separated using the SDS-PAGE method and the images were captured and analyzed using Quantity One software. The target protein bands were subjected to in-gel digestion with trypsin and finally analyzed using an ESI-ion trap mass spectrometer. RESULTS: A total of 50 differentially expressed proteins in colonic cancerous and normal tissues were identified. CONCLUSION: Many of the identified proteins have been reported to be involved in the progression of similar or other types of cancers. However, some of the identified proteins have not been reported before. In addition, a number of hypothetical proteins were also identified.