In addition, there is no clear hypothesis or rationale for a sex-based subgroup analysis in the Introduction or Methods LDE225 section. The Methods and Results sections were searched for information regarding a statistical test for interaction between sex and the SVR, but no mention was found. In contrast, the authors properly placed equal emphasis on sex-based subgroup

results as they did with the overall trial results. Given the frequency with which subgroup analyses by sex are now being performed, it is paramount that investigators should caution the scientific community in their interpretation. Discussion of the sex-specific effects of metformin in chronic HCV infection should be considered proper only when sex-specific analysis are viewed as hypothesis-generating,

and further research to confirm these observations is recommended. Diego Geroldi*, Enzo Emanuele†, * Department of NVP-BKM120 mw Internal Medicine and Medical Therapeutics, University of Pavia, Pavia, Italy, † Department of Health Sciences, University of Pavia, Pavia, Italy. “
“We read with interest the article titled “Copper-Metallothionein Autofluorescence” by Quaglia et al.1 The authors mentioned: (1) fluorescence microscopy is based on the interactions between light wavelengths, molecules, and filters/dichromatic mirrors, which may unmask specific combinations for the identification of particular structures; (2) autofluorescence-based

techniques have been used for the assessment of fibrosis, cell metabolism, and differentiation; discrimination diglyceride between neoplastic and non-neoplastic tissue; and studies of microorganisms and drug interaction. We agree with the authors’ descriptions concerning fluorescence microscopic techniques. However, we should usually recognize that these factors are restrictive and exceptional. Here, we would like to demonstrate that there was another possibility in their observations. Their fluorescence microscopy systems were as follows: dichromatic mirror reflecting at 415 nm wavelength, excitation filter at 420 ± 30 nm wavelength, and suppression filter at 465 ± 20 nm wavelength. The unstained 6-μm-thick sections were excited at the regions between 390 nm and 415 nm. These regions did not match for autofluorescence from copper-metallothioneins (minutely cuprous [Cu(I) or Cu+] metallothioneins [MTs]), because a maximum peak of excitation wavelength for Cu(I)-MTs is around 300 nm.2 Therefore, it can be imagined that the emission from Cu(I)-MTs was very weak. Mysteriously, the red-orange autofluorescence, which originated from Cu(I)-MTs at around 600 nm,2 was observed when illuminated with the excitation filter, although the suppression filter at 465 ± 20 nm shades the light of wavelength more than 485 nm.