Background: Autoimmune diseases like pemphigus and systemic lupus erythematosus are protective against skin malignancies like basal cell carcinoma and squamous cell carcinoma. Objective: As vitiligo is an autoimmune d...Background: Autoimmune diseases like pemphigus and systemic lupus erythematosus are protective against skin malignancies like basal cell carcinoma and squamous cell carcinoma. Objective: As vitiligo is an autoimmune diseases, the aim of the present work is to record the frequency of all benign and malignant skin tumors among patients with different severity of vitiligo and to be compared with the skin tumors in healthy control. Patients and Methods: This is a case series, descriptive study done in the Department of Dermatology—Baghdad Teaching Hospital, Baghdad, Iraq, during the period from May 2014-May 2015. History was taken from each patient with vitiligo regarding age, gender, duration, personal and family history of vitiligo and other autoimmune diseases such as diabetes mellitus, thyroid dysfunction, and alopecia areata. Patients were assessed for past and present history of photodermatosis and any skin cancers. Healthy control was considered. Results: Three hundred and fifty patients with vitiligo were included in this study: 50 patients with universal vitiligo, 100 patients with generalized vitiligo, and 200 patients with localized vitiligo as well as 500 subjects as a healthy control. The ages of all studied subjects ranged between 31 and 77 years. Twenty four(48%) patients with universal vitiligo were males and 26 (52%) were females;49(49%) patients with generalized vitiligo were males and 51(51%) were females;101(50.5%) patients with localized vitiligo were males and 99(49.5%) were females and 235(47%) of control were males and 265(53%) were females. All skin tumors were seen to be high in healthy subjects and lower or absent in patients with vitiligo. Also patients with mild vitiligo had a higher frequency of skin tumors including benign and malignant than patients with severe vitiligo especially in patients with universal vitiligo. In addition, no photosensitivity or actinic reticuloid was detected in patients with vitiligo. Conclusions: Vitiligo especially generalized and universal type as an autoimmune disease had a protective action against photodamage, photosensitivity and skin tumors whether benign or malignant.展开更多
Photosystem II(PSII),as a multiple-subunit chloroplast membrane-associated pigment-protein complex on the thylakoid membrane,is a primary target of light-induced photodamage.However,the overall molecular details of th...Photosystem II(PSII),as a multiple-subunit chloroplast membrane-associated pigment-protein complex on the thylakoid membrane,is a primary target of light-induced photodamage.However,the overall molecular details of the conformation and composition dynamics of PSII photodamage are still controversial.In this study,we investigated systematically the dynamic conformation,degradation,and oxidation processes of PSII photodamage by integrating chemical cross-linking and top-down proteomics strategies.展开更多
Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complex...Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complexes was investigated using absorption, fluorescence, circular dichroism (CD) spectroscopy and SDS-PAGE. It was found from the optical absorption spectra that the maximal ab-sorbance of PSI complexes decreased and maximal peaks blue-shifted during the illumination, and the forth derivative spectra demonstrated that the absorbance decreasing at red region mainly resulted from the aborbance decreasing of the long wavelength Chla, implying that the long-wavelength Chla was readily to be bleached. The CD signals contributed by LHCI decreased more rapidly than other CD signals con-tributed by Chla and Carotenoid, indicating that the LHCI was more sensitive to light than core complexes. It was observed by SDS-PAGE that some small polypeptides of PSI complexes were damaged earlier than reaction展开更多
Hypocrellin B (HB) is a highly effective photosensitizer. One of its derivatives, 5_brominated_hypocrellin B (5_Br_HB) has better photosensitive characteristics than it. Using Raman spectroscopy, the microcosmic photo...Hypocrellin B (HB) is a highly effective photosensitizer. One of its derivatives, 5_brominated_hypocrellin B (5_Br_HB) has better photosensitive characteristics than it. Using Raman spectroscopy, the microcosmic photodamage to DNA sensitized by HB and 5_Br_HB was studied at molecular level. The results showed that when HB and 5_Br_HB were added to the solution of DNA and irradiated, the characteristic Raman frequencies and intensities of DNA changed to various degrees. The photodamage occurred on the whole DNA molecule, including phosphate backbone,deoxyribose and four bases. Not only the conformation but also the configuration of DNA was photodamaged: breakage of some H_bonds, disappearance of B_form conformation , scission of double or single strand and serious damage of four bases. The damage to A_T pairs was stronger than that to C_G pairs and DNA became polynucleotides finally. The 5_Br_HB_photosensitized damage to DNA was stronger than HB , which suggested the better photosensitive characteristics of 5_Br_HB in bioactive environment. The molecular mechanisms of photodamage to DNA sensitized by 5_Br_HB and HB were also elucidated.展开更多
文摘Background: Autoimmune diseases like pemphigus and systemic lupus erythematosus are protective against skin malignancies like basal cell carcinoma and squamous cell carcinoma. Objective: As vitiligo is an autoimmune diseases, the aim of the present work is to record the frequency of all benign and malignant skin tumors among patients with different severity of vitiligo and to be compared with the skin tumors in healthy control. Patients and Methods: This is a case series, descriptive study done in the Department of Dermatology—Baghdad Teaching Hospital, Baghdad, Iraq, during the period from May 2014-May 2015. History was taken from each patient with vitiligo regarding age, gender, duration, personal and family history of vitiligo and other autoimmune diseases such as diabetes mellitus, thyroid dysfunction, and alopecia areata. Patients were assessed for past and present history of photodermatosis and any skin cancers. Healthy control was considered. Results: Three hundred and fifty patients with vitiligo were included in this study: 50 patients with universal vitiligo, 100 patients with generalized vitiligo, and 200 patients with localized vitiligo as well as 500 subjects as a healthy control. The ages of all studied subjects ranged between 31 and 77 years. Twenty four(48%) patients with universal vitiligo were males and 26 (52%) were females;49(49%) patients with generalized vitiligo were males and 51(51%) were females;101(50.5%) patients with localized vitiligo were males and 99(49.5%) were females and 235(47%) of control were males and 265(53%) were females. All skin tumors were seen to be high in healthy subjects and lower or absent in patients with vitiligo. Also patients with mild vitiligo had a higher frequency of skin tumors including benign and malignant than patients with severe vitiligo especially in patients with universal vitiligo. In addition, no photosensitivity or actinic reticuloid was detected in patients with vitiligo. Conclusions: Vitiligo especially generalized and universal type as an autoimmune disease had a protective action against photodamage, photosensitivity and skin tumors whether benign or malignant.
基金The authors gratefully acknowledged the financial supports from the National Key R&D Program of China(nos.2016YFF0200504,2017YFA0503700,and 2018YFA0900702)the National Natural Science Foundation of China(nos.91853101 and 31470339)+3 种基金grants from the Chinese Academy of Sciences(nos.ZDBS-LYSLH032 and XDB17000000)the Liaoning Province(no.2019-YQ-07)the Dalian Institute of Chemical Physics(DICPno.DICP I202007).
文摘Photosystem II(PSII),as a multiple-subunit chloroplast membrane-associated pigment-protein complex on the thylakoid membrane,is a primary target of light-induced photodamage.However,the overall molecular details of the conformation and composition dynamics of PSII photodamage are still controversial.In this study,we investigated systematically the dynamic conformation,degradation,and oxidation processes of PSII photodamage by integrating chemical cross-linking and top-down proteomics strategies.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39890390) the State Key Basic Research and Development Program (Grant No. G1998010100) and the Innovative Foundation of Laboratory of Photosynthesis Basic Research
文摘Purified PSI complexes from Spinacia Oleracea L. were exposed to the strong light (PFD=2300μmol m-2s-1) for various period. Along with the illumination the photo-damage process of pigments and proteins of PSI complexes was investigated using absorption, fluorescence, circular dichroism (CD) spectroscopy and SDS-PAGE. It was found from the optical absorption spectra that the maximal ab-sorbance of PSI complexes decreased and maximal peaks blue-shifted during the illumination, and the forth derivative spectra demonstrated that the absorbance decreasing at red region mainly resulted from the aborbance decreasing of the long wavelength Chla, implying that the long-wavelength Chla was readily to be bleached. The CD signals contributed by LHCI decreased more rapidly than other CD signals con-tributed by Chla and Carotenoid, indicating that the LHCI was more sensitive to light than core complexes. It was observed by SDS-PAGE that some small polypeptides of PSI complexes were damaged earlier than reaction
文摘Hypocrellin B (HB) is a highly effective photosensitizer. One of its derivatives, 5_brominated_hypocrellin B (5_Br_HB) has better photosensitive characteristics than it. Using Raman spectroscopy, the microcosmic photodamage to DNA sensitized by HB and 5_Br_HB was studied at molecular level. The results showed that when HB and 5_Br_HB were added to the solution of DNA and irradiated, the characteristic Raman frequencies and intensities of DNA changed to various degrees. The photodamage occurred on the whole DNA molecule, including phosphate backbone,deoxyribose and four bases. Not only the conformation but also the configuration of DNA was photodamaged: breakage of some H_bonds, disappearance of B_form conformation , scission of double or single strand and serious damage of four bases. The damage to A_T pairs was stronger than that to C_G pairs and DNA became polynucleotides finally. The 5_Br_HB_photosensitized damage to DNA was stronger than HB , which suggested the better photosensitive characteristics of 5_Br_HB in bioactive environment. The molecular mechanisms of photodamage to DNA sensitized by 5_Br_HB and HB were also elucidated.
