Intracellular pH sensing using autofluorescence lifetime microscopy

Fluorescence lifetime images of reduced nicotinamide adenine dinucleotide (NADH) that is a key cofactor in cellular metabolism were obtained in a cell at various values of intracellular pH. The average fluorescence lifetime of NADH is found to become shorter monotonically with increasing pH, indicating that pH in a single cell can be determined by fluorescence lifetime imaging of NADH without adding exogenous fluorescent probes. The magnitude of the pH-induced lifetime change is higher in cells than that in buffer solution. The fluorescence lifetime of NADH is not uniform inside a cell; the fluorescence lifetime of nuclear NADH is shorter than that of mitochondrial NADH at each pH, and the magnitude of the pH-induced change is larger in nuclei than in other areas. The local electric field effect on the fluorescence lifetime is discussed since this effect may be one of the strong possibilities for the nonuniformity of the autofluorescence lifetime of NADH in cells.

Effects of heating procedures on deoxynivalenol, nivalenol and zearalenone levels in naturally contaminated barley and wheat

The influence of heating temperature and time on deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEA) contents in naturally co-contaminated barley and wheat was investigated intending to establish the basis for a decontamination model of Fusarium mycotoxins in cereals. The standard toxins and whole barley powder samples were heated in a convection oven at 140, 160, 180, 200, or 220 degrees C, and kernel subsamples (200 g each) were roasted in an experimental rotary gas-fired roaster at 150, 180 or 220 degrees C. All treatments resulted in a time-temperature-dependent decomposition of the toxins; the logarithm of the toxin remaining % presented a linear relationship with heating time. The lines equations were used to estimate the half (H) and decimal (D) decomposition times (time required to destroy 50 or 90% of the toxin, respectively). DON and NIV H and D decomposition times were similar and 50% shorter for heated standards than for whole barley powder. ZEA standard values were considerably longer, while whole barley powder values were comparable with those of DON and NIV. At 220 degrees C, D decomposition times of DON, NIV and ZEA heated standards were 11, 10 and 85 min, respectively, while the values obtained in whole barley powder were the same for the three toxins (25 min). The determination of H and D decomposition values constitutes a basis to understand the heating stability nature of each toxin.

Menopause in Australia and Japan: effects of country of residence on menopausal status and menopausal symptoms

OBJECTIVES

The aim of the study was to explore the effects of country of residence on menopausal status and menopausal symptoms in Australian and Japanese women. The study objectives included exploring the impact of country of residence (Australia and Japan) and menopausal status on menopausal symptoms, and identifying whether country of residence (Australia and Japan) moderates the relationship between menopausal status and menopausal symptoms.

METHODS

Analyses are based on 1743 women aged between 40 and 60 years who participated in the multi-race, multi-site, cross-sectional study of mid-aged women called the Australian and Japanese Midlife Women's Health Study (AJMWHS) in 2001--2002. Study participants completed a mailed questionnaire that contained questions on a variety of health-related topics.

RESULTS

In both cultures there was a similar increase in prevalence of depression (p < 0.001), somatic symptoms (p < 0.001) and vasomotor symptoms (p < 0.001) at perimenopause. Australian women experienced more night sweats than Japanese women but the prevalence of hot flashes was not statistically different. Postmenopausal Japanese women had more somatic, psychological and sexual symptoms. The main effect for menopausal status and the interaction effect of country of residence was significant in the somatic symptoms (p < 0.001), but not in any of the other areas.

CONCLUSIONS

Vasomotor, psychological and somatic symptoms decrease after menopause in Australian women, with only sexual symptoms continuing. In Japanese women, somatic, psychological and sexual symptoms remain high after menopause. It is possible that westernization may be having a significant impact on the aging of women in Japan and it is, therefore important to capture through research just what this impact may be.

Transvaginal mesh (TVM) reconstruction with TVT/TOT sling for vaginal prolapse concurrent with stress urinary incontinence

We evaluated clinical efficacies of transvaginal mesh (TVM) reconstruction alone and those concomitant with a TVT/TOT sling for the treatment of pelvic organ prolapse (POP) and stress urinary incontinence (SUI). Between January 2006 and February 2007, 138 female patients with POP underwent TVM reconstruction. The mean age was 66.6 years (range: 52-84). Fourteen individuals were qualified as grade II in the POP quantification (POP-Q) system, 85 and 39 were grades III and IV, respectively. One hundred and seventeen of 138 (85 %) cases showed SUI. Twenty-one patients without SUI underwent TVM alone, and 117 cases with SUI underwent TVM concomitant with TVT/TOT sling. Mean operation time and intra-operative bleeding was 79 min (range: 25-177) and 74 ml (range: 10-429), respectively. Mean follow-up period is 5.3 months (range: 1-14). The vaginal prolapses were cured (grade 0) in 129 cases (93 %) after the surgery. Total inter-national prostate symptom score (IPSS), its QOL score, International Consultation on Incontinence Questionnaires Short Form (ICIQ-SF) significantly improved (from 12.6 to 3.9; p < 0.0001, from 5.0 to 1.0; p < 0.0001, and from 6.1 to 2.5; p < 0.01, respectively). Six of 21 cases (29%) who underwent TVM alone showed postoperative de-novo SUI. In contrast, 116 cases (99%) who underwent TVM concomitant with TVT/TOT, experienced a cure of SUI. Maximum flow rate did not change postoperatively in the both groups. In conclusion, the short-term efficacies of TVM reconstruction for POP are excellent, and a concomitant TVT/TOT sling prevents postoperative SUI.

Pharmacokinetics of Fluorinated 2-nitroimidazole Hypoxic Cell Radiosensitizers in Murine Peripheral Nervous Tissue

We have previously reported that KU-2285, a 2-nitroimidazole with a fluorinated N1-substituent (-CH2-CF2CONH(CH2)nOH, n = 2), was a promising hypoxic cell radiosensitizer. In this study the pharmacokinetics of KU-2285 and its related compounds (n = 3 and n = 4) were compared with those of etanidazole (a 2-nitroimidazole with an N1-substituent of -CH2CONH(CH2)nOH, n = 2) and its related compounds (n = 3 and n = 4) to assess the effects of incorporation of a CF2 group. The lipophilicity of the fluorinated compounds was higher than that of etanidazole, as measured by the octanol/water partition coefficient. As the number of CH2 groups increased, the lipophilicity of the compounds in both the KU-2285 and etanidazole series increased. The brain tissue levels of the fluorinated compounds were as low as those of the etanidazole derivatives, while the biological half-lives of the fluorinated compounds in peripheral nervous tissues were shorter than those of related non-fluorinated compounds.

A novel macrocyclic spermine alkaloid from Incarvillea sinensis

A novel macrocyclic spermine alkaloid incasine C' (1), along with a known compound incasine C (2), were isolated from the whole plants of Incarvillea sinensis, and their structures were elucidated on the basis of chemical and spectroscopic evidence.

External Electric Field Effects on Fluorescence of Pyrene Butyric Acid in a Polymer Film: Concentration Dependence and Temperature Dependence

Fluorescence spectra and electrofluorescence spectra (plots of the electric field-induced change in fluorescence intensity as a function of wavelength) have been measured at different temperatures for pyrene butyric acid (PBA) in a PMMA film at different concentrations. At a low concentration of 0.5 mol % where fluorescence emitted from the locally excited state of PBA (LE fluorescence) is dominant, LE fluorescence spectra show only the Stark shift in the presence of an electric field (F), which results from the difference in molecular polarizability between the ground and emitting states. At a high concentration of 10 mol % where the so-called sandwich-type excimer fluorescence (EX(1)) is dominant, both EX(1) and LE fluorescence are quenched by F. Another fluorescence assigned to a partially overlapped excimer (EX(2)) also exists at room temperature, and this emission is enhanced by F. As the temperature decreases, three fluorescence emissions whose electric field effects are different from each other become clear besides EX(1) and LE fluorescence, indicating that at least five fluorescence components exist at high concentrations at low temperatures. At a medium concentration of 5 mol % where EX(1) is comparable in intensity to the LE fluorescence, the intensity of EX(1) is not affected by F at any temperature, but LE fluorescence and EX(2) are markedly influenced by F at room temperature, and four fluorescence emissions are confirmed at low temperatures.

Electroabsorption Spectroscopy of 6-Hydroxyquinoline Doped in Polymer Films: Stark Shifts and Orientational Effects

Stark absorption spectroscopy was applied to 6-hydroxyquinoline (6-HQ) doped in polymer films of poly(methyl methacrylate) (PMMA) and poly(vinyl alcohol) (PVA) at temperatures of 50-300 K. The electroabsorption (E-A) spectrum of 6-HQ markedly depends on temperature in a PMMA film. The polarization dependence as well as the temperature dependence of the E-A spectra reveals that 6-HQ is oriented along the direction of the applied electric field at room temperature in a PMMA film. As the temperature becomes lower, the field-induced orientation of 6-HQ is restricted, and only the Stark shift induced by a change in electric dipole moment and in molecular polarizability is observed. On the other hand, E-A spectra of 6-HQ doped in a PVA film are essentially independent of temperature, suggesting that 6-HQ is not oriented along the electric field even at room temperature in PVA. These results show that the molecular motion of 6-HQ in a polymer film is very sensitive to the microenvironment of the surrounding matrix.

Evaluation of a method to determine the natural occurrence of aflatoxins in commercial traditional herbal medicines from Malaysia and Indonesia

Traditional herbal medicines, popularly known as 'jamu' and 'makjun' in Malaysia and Indonesia, are consumed regularly to promote health. In consideration of their frequent and prolonged consumption, the natural occurrence of aflatoxins (AF) in these products was determined using immunoaffinity column clean-up and high-performance liquid chromatography with pre-column derivatization. The evaluated method, which entails dilution of sample extracts with Tween 20-phosphate buffered saline (1:9, v/v) and a chromatographic system using isocratic mobile phase composed of water-methanol-acetonitrile (70:20:10, v/v/v), was effective in separating AFB1, AFG1 and AFG2 from interference at their retention times. Results were confirmed using post-column derivatization with photochemical reactor. For 23 commercial samples analyzed, mean levels (incidence) of AFB(1), AFB(2) and AFG1 in positive samples were 0.26 (70%), 0.07 (61%) and 0.10 (30%) microg/kg, respectively; one sample was positive for AFG2 at a level of 0.03 (4%) microg/kg. In contrast to the high levels of AF in crude herbal drugs and medicinal plants reported previously by other researchers, the low contamination levels reported in this study may be attributed to the higher selectivity to AF of the method applied. Based on the AFB1 levels and the daily consumption of positive samples, a mean probable daily intake of 0.022 ng/kg body weight was calculated.

Spectroscopic and Excited-State Properties of Tri-9-anthrylborane II: Electroabsorption and Electrofluorescence Spectra

Electroabsorption and electrofluorescence spectroscopies were conducted for tri-9-anthrylborane (TAB) doped in poly(methyl methacrylate) films (1.0 mol %) to reveal the spectroscopic and excited-state properties of the compound. TAB showed three distinct absorption bands: bands I [(19 - 25) x 10(3) cm(-1)], II [(25-31) x 10(3) cm(-1)], and III (>31 x 10(3) cm(-1)). The electroabsorption spectrum demonstrated that the electronic transitions in bands I and III accompanied electric dipole moment changes (Deltamu), while the change in the molecular polarizability contributed mainly to electroabsorption band II. Because of the similarities of the electroabsorption spectrum of band II with that of anthracene itself, band II was assigned to the electronic transition to the locally excited (LE) state of the anthryl group. On the other hand, bands I and III were best described by the electronic transitions to the excited charge-transfer (CT) states. The study demonstrated furthermore that the Deltamu value of TAB accompanied by the lowest-energy electronic transition was as large as 7.8 D, which agreed very well with that determined by the solvent dependences of the absorption and fluorescence maximum energies of TAB (approximately 8.0 D, ref 1): Deltamu = 7.8-8.0 D. The results proved explicitly that the excited state of TAB was localized primarily on the p orbital of the boron atom. Despite the dipole moment change (Deltamu = 7.8-8.0 D) for the lowest-energy electronic transition (band I), the electrofluorescence of TAB accompanied the change in the molecular polarizability. The spectroscopic and excited-state properties of TAB including the curious behavior of the electrofluorescence spectrum as mentioned above were discussed on the basis of theoretical considerations.

Microbiological and physicochemical factors affecting Aspergillus section Flavi incidence in Cavendish banana (Musa cavendishii) chips production in Southern Philippines

Microbiological and physicochemical factors affecting the incidence of Aspergillus section Flavi in dried Cavendish banana (Musa cavendishii) chips production in Southern Philippines were examined. The average counts of Aspergillus section Flavi (AFC) in fresh and dried Cavendish bananas from 10 production batches of the Philippine Agro-Industrial Development Cooperative in Davao del Norte, Southern Philippines were 1.2 x 10(2) and 1.6 x 10(2) cfu/g, respectively. Isolates from both samples were identified to be Aspergillus flavus based on spore type and conidial structure of isolates. An increasing trend in the AFC of Cavendish bananas was observed during dried banana chips processing. Variability in the AFC between production batches was attributed to differences in aerobic and fungal populations and physicochemical characteristics of the fruits, peel damage of the raw materials, concentration of AFC in the air and food-contact surfaces of the production area, and temperature and relative humidity (RH) conditions of the environment during production and storage. Physicochemical characteristics of Cavendish bananas from the receipt of raw materials up to the first day of drying were within the reported range of values allowing growth and toxin production by aflatoxigenic fungi. Air-borne AFC varied depending on the section of the production area examined. The close proximity of the waste disposal area from the production operation to the preparation, drying and storage areas suggests that cross-contamination, probably air-borne or insect-borne was a likely occurrence. The hands of workers were also identified as AFC sources. Results of this study highlight the need for the development of strategies to control aflatoxigenic fungi and aflatoxin contamination in Philippine dried Cavendish bananas.