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Biomedical subjects

Allan B MacLean

Publications and source records attributed to Allan B MacLean.

5 recordsLinked to original sources

Acetowhite epithelium.

OBJECTIVE: The study was undertaken to provide further understanding of the phenomenon of "acetowhite epithelium". METHODS: Solutions of acetic and similar acids were applied to the atypical transformation zone to demonstrate (or not) acetowhite epithelium. RESULTS: Acetowhite epithelium is not unique to acetic acid, but can be mimicked by other water soluble carboxylic acids. CONCLUSIONS: Acetowhite epithelium is probably due to the reflection of light from the superficial layers of epithelium when they become opaque following the rapid penetration of these non-coagulant fixatives and their effect on nucleoprotein.

Acetic Acid↗

The role of angiogenesis in vulvar cancer, vulvar intraepithelial neoplasia, and vulvar lichen sclerosus as determined by microvessel density analysis.

OBJECTIVES: We compared microvessel density (MVD) in normal, benign, preneoplastic, and neoplastic (squamous cell carcinoma (SCC)) vulvar disease to ascertain if this parameter could identify cases with lichen sclerosus (LS) and high-grade vulvar intraepithelial neoplasia (VIN3) at risk of developing malignancy. METHODS: Microvessels were immunohistochemically stained in paraffin wax-embedded vulvar tissue sections with anti-von Willebrand factor (vWF) antibody using the streptavidin-biotin-horseradish peroxidase complex technique. Three "hot spots" with the greatest MVD were identified within 200 microm of the subepithelial dermis under low magnification (x 40 and x 100). The highest (HVD) and average (AVD) MVDs were quantified for each sample under high magnification (x 200) using an image analysis system. RESULTS: HVD and AVD showed similar significant differences. SCC had significantly the highest MVD followed by VIN3, normal vulva, and LS. LS had significantly the lowest MVD, even lower than that of normal vulva. Two cases of VIN3 had much higher HVD (9.16 and 9.61) and AVD (6.89 and 7.71) compared with the main cluster of cases. CONCLUSION: In vulvar LS, MVD, as assessed by HVD/AVD, is not a useful parameter in determining potential malignant progression, while in VIN3 this parameter could be valuable in identifying cases at greatest risk of progression to invasive disease.

Adult↗

Estrogen receptor expression in vulvar vestibulitis syndrome.

OBJECTIVE: A pilot study was performed to investigate the relationship between vulvar vestibulitis syndrome and estrogen receptor expression. STUDY DESIGN: Women with a diagnosis of vulvar vestibulitis syndrome had tissue samples taken for vulvar estrogen receptor-alpha expression and this was compared with a control group. RESULTS: The study group showed a significant decrease in estrogen receptor expression, and 50% of the samples did not exhibit any receptor expression. CONCLUSION: There appears to be a subgroup of women with vulvar vestibulitis syndrome who exhibit abnormal estrogen receptor-alpha expression. This may be helpful in explaining why some women are resistant to medical treatment and may allow treatment to be prescribed more effectively.

Adult↗

Vulvodynia.

PURPOSE OF REVIEW: An increasing number of patients present with symptoms of vulvar pain, soreness, burning or irritation, which become chronic. Clinicians are often uncertain of the diagnosis. Terminology and an understanding of aetiology and therapy are evolving. RECENT FINDINGS: Previous descriptions of vulvodynia have grouped patients according to whether pain is provoked by coitus (vulvar vestibulitis syndrome) or generalized and neuropathic pain (dysesthetic vulvodynia). Recent terminology debates have questioned whether 'vulvodynia' should be replaced by 'dysesthesia' and the term 'vestibulitis' avoided. Definitions of pain provocation, quality, duration, and distribution vary. Prevalence studies suggest one in six women may experience vulvodynia, although such a figure reflects clinic, patient or author reporting bias. Symptoms are as likely to be found in non-white as in white women. Although infection is often blamed, evidence for its role or that of inflammation is minimal. Immunohistochemistry has shown altered density of nerve endings and oestrogen receptors. There may be overlap with other pain syndromes. Several reviews have examined the many therapies available. Pharmacological alteration of nerve conduction (tricyclic antidepressants, gabapentin, local anaesthetics), biofeedback and sometimes surgery are helpful, but not always. Counselling and an understanding between patient and clinician/therapist are important for long-term results. SUMMARY: Gynaecologists should be aware that they will encounter patients with vulvodynia who will need assessment and management. There are increasing numbers of clinics or clinicians with expertise to whom these patients can be referred.

Female↗

The role of vascular endothelial growth factor-A (VEGF-A) and platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) in Paget's disease of the vulva and breast.

BACKGROUND: Paget's disease of the vulva and the breast are uncommon conditions. The pathogenesis underlying these diseases is still unclear. Vascular endothelial growth factor-A (VEGF-A), a potent angiogenic factor, has been demonstrated in a variety of tumour cell types and is thought to be involved in tumour expansion. Platelet-derived endothelial cell growth factor/thymidine phosphorylase (PD-ECGF/TP) has also been shown to stimulate angiogenesis. MATERIALS AND METHODS: Fifty-four cases of Paget's disease of the vulva, including 10 with an associated invasive adenocarcinoma, and 38 cases of Paget's disease of the breast, including 26 with available associated ductal carcinoma in situ (DCIS) and/or invasive carcinoma of the breast, were evaluated immunohistochemically for the expression of VEGF-A and PD-ECGF/TP. RESULTS: VEGF-A was not expressed in Paget's disease of the vulva or breast. PD-ECGF/TP was expressed in 22 out of 54 (41%) cases of Paget's disease of the vulva. Four of the cases associated with invasive disease (40%) expressed PD-ECGF/TP. Twenty-one out of 38 (55%) cases of Paget's disease of the breast were positive for PD-ECGF/TP. CONCLUSION: Our data suggest that PD-ECGF/TP may have a role to play in the pathogenesis of Paget's disease of the vulva and the breast. The role of VEGF-A in Paget's disease of the vulva and the breast remains to be fully elucidated.

Breast Neoplasms↗