Noura A. Moussa

Low-level laser therapy: a useful technique for enhancing the proliferation of various cultured cells

The aim of this work is to review the available literature on the details of low-level laser therapy (LLLT) use for the enhancement of the proliferation of various cultured cell lines including stem cells. A cell culture is one of the most useful techniques in science, particularly in the production of viral vaccines and hybrid cell lines. However, the growth rate of some of the much-needed mammalian cells is slow. LLLT can enhance the proliferation rate of various cell lines. Literature review from 1923 to 2010. By investigating the outcome of LLLT on cell cultures, many articles report that it produces higher rates of ATP, RNA, and DNA synthesis in stem cells and other cell lines. Thus, LLLT improves the proliferation of the cells without causing any cytotoxic effects. Mainly, helium neon and gallium-aluminum-arsenide (Ga-Al-As) lasers are used for LLLT on cultured cells. The results of LLLT also vary according to the applied energy density and wavelengths to which the target cells are subjected. This review suggests that an energy density value of 0.5 to 4.0 J/cm2 and a visible spectrum ranging from 600 to 700 nm of LLLT are very helpful in enhancing the proliferation rate of various cell lines. With the appropriate use of LLLT, the proliferation rate of cultured cells, including stem cells, can be increased, which would be very useful in tissue engineering and regenerative medicine.

Perceptions, attitudes and practices toward research among senior medical students.

We aimed to explore perceptions, attitudes and practices toward research among medical students. A self-administered questionnaire was distributed among senior medical students at the King Saud University, Riyadh, Saudi Arabia. Hundred and seventy two students participated in the study, with 97 males (65.5%). The majority of the students agreed that research is important in the medical field (97.1%, 167/172). A total of 67.4% (116/172) believed that conducting research should be mandatory for all medical students. During medical school, 55.3% (88/159) participated in research. The obstacles that prevented the students from conducting research included lack of professional supervisors (84.7%, 143/169), lack of training courses (88.8%, 151/170), lack of time (72.3%, 123/172) and lack of funding (54.1%, 92/170). Although the majority of students believe that research is important in the medical field, only around half of the students participated in research during medical school.

The role of vitamin D in melanogenesis with an emphasis on vitiligo.

Vitiligo is a common pigmentary disorder caused by the destruction of functional melanocytes. Vitamin D is an essential hormone synthesized in the skin and is responsible for skin pigmentation. Low levels of vitamin D have been observed in vitiligo patients and in patients with other autoimmune diseases. Therefore, the relationship between vitamin D and vitiligo needs to be investigated more thoroughly. We reviewed the literature to date regarding the role of vitamin D in skin pigmentation. Our review revealed that vitamin D deficiency has been identified in many conditions, including premature and dysmature birth, pigmented skin, obesity, advanced age, and malabsorption. Vitamin D increases melanogenesis and the tyrosinase content of cultured human melanocytes by its antiapoptotic effect. However, a few growth-inhibitory effects on melanocytes were also reported. Vitamin D regulates calcium and bone metabolism, controls cell proliferation and differentiation, and exerts immunoregulatory activities. Vitamin D exerts its effect via a nuclear hormone receptor for vitamin D. The topical application of vitamin D increased the number of L-3,4-dihydroxyphenylalanine-positive melanocytes. The topical application of vitamin D yields significant results when used in combination with phototherapy and ultraviolet exposure to treat vitiligo in humans. Vitamin D decreases the expression of various cytokines that cause vitiligo. In conclusion, application of vitamin D might help in preventing destruction of melanocytes thus causing vitiligo and other autoimmune disorders. The association between low vitamin D levels and the occurrence of vitiligo and other forms of autoimmunity is to be further evaluated.

Is there a real relationship between serum level of homocysteine and vitiligo? A controlled study on 306 subjects.

To the Editor: Vitiligo is a skin disease characterized by the development of white macules and patches. The etiology of vitiligo is complex; there appears to be a certain genetic predisposition and a number of potential precipitating causes. Reduced serum levels of folic acid (FA) and vitamin B12 have been found in patients with vitiligo. It has been reported that vitiligo improves after treatment with FA and vitamin B12. 6 Both FA and vitamin B12 are required as cofactors by the enzyme homocysteine methyltransferase for the regeneration of methionine from homocysteine (Hcy) in the activated methyl cycle. Consequently, a nutritional deficiency in either of these two vitamins results in an increase in Hcy and a decrease in methionine levels in the circulation. It was also suggested that Hcy has an inhibitory action on histidase and tyrosinase activity of the skin. Therefore, it is possible that an increase in local Hcy interferes with normal melanogenesis and plays a role in the pathogenesis of vitiligo. Our study included 153 vitiligo patients and 153 ageand sex-matched controls. The duration of vitiligo, activity of the disease, and family history for vitiligo were noted, and the percentage of the area of the vitiligo lesions was measured. The exclusion criteria included intake of FA, vitamin B12, or vitamin B6 or hormonal therapy; pregnancy; cigarette smoking; having diseases known to affect Hcy levels, including genetic disorders of amino acid metabolism; and any comorbid disease. A fasting 3 mL blood sample was drawn and centrifuged at 3,000g after clotting for 10 minutes. Serum Hcy was measured using the Axis Homocysteine Enzyme Immunoassay kit (Axis-Shield Diagnostics Ltd., Dundee, UK). This kit is an enzyme immunoassay for the determination of Hcy in blood. Serum levels of FA and vitamin B12 were assessed by immunoassay using an autoanalyzer (Unicel DxI 800, Access Immunoassay System, Beckman Coulter, Inc., Fullerton, CA). FA levels of , 2.5 ng/mL ( normal range 2.7–17.0 ng/mL), vitamin B12 levels of , 190 pg/mL (normal range 200–800 pg/mL), and Hcy levels of . 20 mmol/L were considered abnormal (normal range 5.7–19.6). The median age of the patients was 28 years (range 22– 34.5 years). Eighty-seven patients were male and 66 were female. The mean duration of vitiligo was 8.5 years (range 4–15 years). The body surface area ranged between 0.1 and 23%. The median serum Hcy level in cases and controls was 12.73 mmol/L and 12.94 mmol/L, respectively (p 5 .94). The median FA level was 10.0 ng/mL in patients and 7.60 ng/mL in controls (p 5 .001). The median vitamin B12 level was 351.6 pg/mL in patients and 356.85 pg/mL in controls (p 5 .76) (Table 1). The median levels of Hcy, FA, and vitamin B12 were not affected by the type of vitiligo and activity (p 5 .08) (Table 2 and Table 3). The results of our study revealed that there was no association between serum levels of Hcy and vitamin B12 and vitiligo (see Table 1). FA was higher in patients than in controls, which is contrary to a previous study. It is unclear whether this may be attributable to genetic or nutritional factors. In a study by Karadag and colleagues, subjects with vitiligo had significantly higher homocysteine levels than controls but lower vitamin B12 and holotranscobalamine levels. A study by Shaker and El-Tahlawi revealed that the mean serum Hcy level was significantly higher in patients with progressive disease. However, the sample size was extremely small (26 patients only), which was not enough to make viable statistical decisions, and no controls were used. Another recent study by Silverberg and Silverberg demonstrated the association between serum Hcy and extent of vitiligo, suggesting Hcy as a new biomarker of vitiligo extent. Another conflicting study by Balci and colleagues on the same issue revealed that there was no relationship between serum Hcy, FA, and vitamin B12 levels and vitiligo. 13 Singh and colleagues reported higher levels of Hcy in male vitiligo patients compared to healthy controls. The Hcy level in vegetarian patients was significantly higher compared to that in nonvegetarian patients. Our results are somewhat different from those of previous studies, which reported no significant differences in FA levels in vitiligo patients compared to healthy controls. This might help resolve the conflict in the DOI 10.2310/7750.2013.13050

Local side effects caused by hair dye use in females: cross-sectional survey.

Background: Despite its association with a number of side effects, hair dye use is common worldwide. Objective: To explore the local side effects of hair dye use and to relate these effects to features of hair dyeing. Methods: A questionnaire about hair dye use was distributed to a random sample of 650 female patients at various outpatient clinics in 2008. Results: A total of 567 females returned the questionnaire (87.2% response rate). Of these respondents, 82.6% (464 of 562) had used hair dye products in the past. The mean age at first use was 22.23 ± 7.05 years, and the median time between two consecutive dyes was 6 months. Of these respondents, 76.8% (354 of 461) used permanent dyes. Participants reported that they suffered skin redness caused by hair dyes (15.1%, 65 of 431), had scaling (14.4%, 60 of 417), or had itchiness (31.3%, 134 of 428). In addition, 74% (262 of 354) of the participants reported that they had issues with the texture or condition of hair following hair dye use; 77.7% (314 of 404) reported split ends, whereas 69.6% (273 of 392) reported hair dryness, 69.4% (256 of 369) lusterless hair, 77.2% (308 of 399) excessive hair loss, and 53.6% (210 of 392) excessive hair graying. Furthermore, 55.1% (196 of 356) of the participants reported a slowing of hair growth. The total number of hair dyeing events was associated with increased hair loss (p = .04) and excessive graying (p < .001) after controlling for all relevant variables. Conclusion: Hair dye is associated with local side effects to the skin and hair. Increased public awareness of these risks could help inform consumer choices and reduce excessive use.

Eyebrow bleaching among females: a cross-sectional study

Background  Eyebrow bleaching is a common practice among women with dark hair that allows for alterations in the eyebrows’ shape without the use of hair removal. A literature search on this topic failed to reveal any extant studies.

Misconceptions about laser treatment among dermatology patients

Background  The use of lasers is very common in dermatology; however, many patients fear it and have various misconceptions about it. A literature search failed to show any studies on this topic.

Mercury levels in vitiligo patients.

To the Editor: Vitiligo is a skin disease characterized by the development of white macules and patches. Although the etiology is not completely known, the major hypothesis is thought to be an autoimmune one. Recent studies have linked elevated levels of mercury with autoimmune diseases such as lupus. An increase in serum mercury has an effect on macrophages, polymorphonuclear leukocytes, and T lymphocytes, which causes autoimmunity and consequently might be playing a role in the pathogenesis of vitiligo. However, mercury levels have not been previously investigated in vitiligo patients, to the best of our knowledge. Our study included 60 vitiligo patients. The duration of vitiligo and family history for vitiligo were noted, and the percentage of the area of the vitiligo lesions was measured. Vitiligo was divided into three groups as active, stable, or regressive according to the progress of the lesions in the last month. The exclusion criteria included having segmental vitiligo, kidney disease, any other autoimmune diseases, and pregnancy or lactation. A fasting 3 mL blood sample was drawn and centrifuged at 3,000g after clotting for 10 minutes. Serum samples were lysed for analysis of heavy metals by adding 10 mL of nitric acid to 1 mL of serum and heated for 3 to 4 hours, and then 1 mL of perchloric acid was added to the sample. The digestion process was continued until the solution was clear. The atomic absorption spectrophotometry–hydride vapor generator method was used to determine serum mercury by using an AA-6650F atomic absorption spectrophotometer (Shimadzu, Kyoto, Japan). Normal values were # 2.0 mg/L for men and women. The mean age of the vitiligo patients was 28.5 6 11.5 years (range 14–68 years). Thirty-six were male and 24 were female. Thirty-two patients (53.3%) had a family history of vitiligo. The mean duration of vitiligo was 9.9 6 8.4 years (range 0.7–36 years). The mean body surface area was 5.8 6 4.9%. The clinical data of the participants are shown in Table 1. All patients had normal mercury levels. The mean serum level of mercury was 2.0 6 0.3 mg/L. Recent studies illustrate the possibility that exposure to heavy metals, such as mercury, can induce an alteration of the cells of the immune system. Exposure to mercury vapors can result in elevated IgE levels and increased T-lymphocyte numbers in humans. The production of mercury-induced autoantibodies depends on T-cell help. Several rodent models exist for mercury-induced autoimmunity. In susceptible rats, subtoxic doses of mercuric chloride induce autoimmunity. This disorder is characterized by production of antibodies, an increase in serum immunoglobulins, polyclonal activation of B and T lymphocytes, and renal immune complex deposition resulting in glomerulonephritis. The autoantibodies produced are of various specificities, including anti–double-stranded deoxyribonucleic acid (DNA), antiphospholipid, and antiglomerular basement membrane. Metal-induced autoimmunity in mice shares