Sameh K. Attia

Expression of p53 in normal sun-exposed and protected skin (type IV-V) in different decades of age.

The checkpoint protein p53, which is activated by DNA damage, is involved in the decision whether the cells should stop replication and proceed to repair their DNA or die by apoptosis. We evaluate the expression of p53 and the number of apoptotic cells in normal sun-exposed (face) and protected (abdomen) skin in Egyptians between 6 and 77 years of age. The degree of p53 expression in facial skin significantly increases from a score of 1.5 +/- 1.5 (mean +/- SEM) in the 1st decade to 4.8 +/- 0.3 in the 8th decade (p = 0.02), while no significant changes are detected in the protected skin (p = 0.1). Overall, the level of expression is significantly higher in sun-exposed facial skin than in abdominal skin (p = 0.007). However, p53 expression versus age is significantly higher in the facial skin of older age groups in both males (p = 0.003) and females (p = 0.02). The pattern of staining was found to be dispersed (wild-type) in the majority (97.3%) of biopsies from sun-exposed skin and in all biopsies from non-exposed skin. The expression of wild-type p53 in type IV-V skin therefore correlates with both site and age of the individual. In contrast, the number of apoptotic cells significantly decreases with advancing age in sun-exposed skin (p = 0.005). Increased age-associated expression of p53 in sun-exposed skin, but not in protected areas of skin, is found to reflect an accumulation of the wild-type protein, as judged by the staining pattern. The decrease in apoptotic cells with age may suggest the accumulation of senescent cells in the skin and their relative resistance to apoptosis. Such alteration in the proliferation/apoptosis balance could play a role in tumorigenesis.

Effect of topical tretinoin on photoaged facial skin: a histometric, immunohistochemical and ultrastructural study

Background  Topical tretinoin is a recognized treatment for photoageing.

Androgenetic alopecia in males: a histopathological and ultrastructural study

BACKGROUND Androgenetic alopecia is a common cosmetic hair disorder, resulting from interplay of genetic, endocrine, and aging factors leading to a patterned follicular miniaturization. Microinflammation seems to be a potential active player in this process. AIMS To study the histopathological and ultrastructural changes occurring in male androgenetic alopecia (AGA). Patients/methods Fifty-five subjects were included in this study (40 with AGA and 15 as normal age-matched controls). Skin biopsies from frontal bald area and occipital hairy area were subjected to histopathological examination, immunohistochemical staining for collagen I and ultrastructural study. RESULTS The frontal bald area of patients showed highly significant increase in telogen hairs and decrease in anagen/telogen ratio and terminal/vellus hair ratio (P < 0.001). Perifollicular inflammation was almost a constant feature in early cases and showed a significant inverse correlation with perifollicular fibrosis (P = 0.048), which was more marked with thickening of the follicular sheath in advanced cases. CONCLUSION Follicular microinflammation plays an integral role in the pathogenesis of AGA in early cases. Over time, thickening of perifollicular sheath takes place due to increased deposition of collagen, resulting in marked perifollicular fibrosis, and sometimes ends by complete destruction of the affected follicles in advanced cases.

Effect of PUVA therapy on melanocytes and keratinocytes in non‐segmental vitiligo: histopathological, immuno‐histochemical and ultrastructural study

Psoralen ultraviolet A (PUVA) is an important modality in treating vitiligo. Its effect on melanocytes and keratinocytes is not sufficiently studied. In this work, we investigated 30 cases of non‐segmental vitiligo regarding the changes of melanocytes and keratinocytes in both vitiliginous and nearby areas before and after PUVA therapy.

The use of Botulinum toxin-A injection for facial wrinkles: a histological and immunohistochemical evaluation

Botulinum toxin (BTX)‐A has been used for years in the reduction of facial wrinkles; however, histological and immunohistochemical changes after its use were not previously investigated. To evaluate histological and immunohistochemical changes after BTX‐A injection for facial wrinkles, sixteen volunteers, with wrinkles on the upper third of the face, were subjected to single injection of BTX‐A. Skin biopsy specimens were obtained from peri‐orbital wrinkle site (crows feet area) before and after 3 months of BTX‐A injection. Using histological and immunohistochemical evaluation coupled with computerized morphometric analysis, measurement of epidermal thickness, wrinkle depth and width as well as quantitative evaluation of collagen types I and III and elastin was performed for skin biopsies. After BTX‐A injections, there were significant increase in wrinkle width and granular layer thickness (P < 0.001), while the other histometrical measures as well as the immunohistochemical expression of collagen types I and III and elastin showed no significant difference (P > 0.05). However, collagen fibers showed better organization and orientation after BTX‐A injection. The histological changes observed after BTX‐A injection for facial wrinkles may help in better understanding of its mechanism of action.

Evaluation of apoptosis regulatory markers in androgenetic alopecia

BACKGROUND Androgenetic alopecia (AGA) is a common androgen-induced progressive disorder; the pathways of which are regulated by local genetic codes and hormonal control. Meanwhile, it is unclear whether an altered proliferation or increased apoptosis could contribute to its pathogenesis. AIMS To evaluate the role of some apoptosis regulatory markers and follicular proliferation in the pathogenesis of AGA. PATIENTS/METHODS Thirty biopsies were taken from the frontal (bald) area and occipital (hair-bearing) area of 15 male patients with AGA, as well as five specimens from the frontal area of five age-matched controls. The biopsies were stained with apoptosis regulatory markers (Bcl-2, p53, Bax & Fas) and PCNA (proliferating cell nuclear antigen), as well as TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling) staining for the detection of DNA fragmentation in apoptotic cells. RESULTS Bcl-2 expression was localized to epidermal basal layer and follicular dermal papilla with highly significant correlation with PCNA expression (P < 0.001). Perifollicular lymphocytic infiltrate of the bald area showed significant expression of Bcl-2. However, pro-apoptotic Bax and Fas were expressed in the epidermis and not in the hair follicles which does not show any apoptotic keratinocytes by TUNEL staining. CONCLUSION The low proliferation rate in the bald area of patients, together with persistent perifollicular inflammatory infiltrate as evidenced by the anti-apoptotic Bcl-2 expression in dermal lymphocytes, would result in follicular miniaturization and fibrosis.

Expression of IFN-γ, IL-4, and IL-17 in cutaneous schistosomal granuloma

Cutaneous schistosomal granuloma (CSG) is a rare dermatological disease, the clinical and histopathological features of which are well defined. Although a panoramic picture of its immunopathogenesis in humans is not yet available, it is believed to be induced by T helper 1 (Th1), Th2, or Th17 cytokines in animals. This study evaluated the expression of different types of Th cytokines, including Th1 cytokine interferon‐γ (IFN‐γ), Th2 cytokine interleukin‐4 (IL‐4), and Th17 cytokine IL‐17, in human CSG.