Time-resolved fluorescence spectroscopy for the diagnosis of oral lichen planus.

BACKGROUND: Lichen planus (LP) is a T-cell mediated autoimmune disorder of unknown aetiology that affects the skin, nails, oral and genital mucous membranes. Conventionally, oral LP (OLP) is diagnosed through clinical assessment and histopathological confirmation by oral biopsy. AIM: To explore the use of time-resolved fluorescence spectroscopy (TRFS) to detect fluorescence lifetime changes between lesional OLP and perilesional normal mucosa. METHODS: In this pilot study, measurements of lesional and perilesional buccal and mouth floor mucosa were conducted in vivo with a TRFS system. Histopathological findings were consistent with OLP in 8 out of 10 patients biopsied. Two patients with histopathological diagnoses of frictional hyperkeratosis and oral candidiasis, respectively, were excluded from the study. RESULTS: Our preliminary data show that lifetime values in the 360-560 nm spectral range indicate a significant differentiation between normal and diseased tissue. In contrast to the standard oral biopsy procedure, this technique is noninvasive, painless, time-efficient and safe. CONCLUSIONS: Future studies are needed to better elucidate the diagnostic capability of TRFS and to further explore the sources of fluorescence contrast. This pilot study suggests that, based on fluorescence lifetime parameters, TRFS is a very promising technology for the development of a novel OLP diagnostic technique.

Unilateral nevoid telangiectasia syndrome (UNTS) associated with chronic hepatitis C virus and positive immunoreactivity for VEGF.

Unilateral Nevoid Telangectasia Syndrome (UNTS) is characterized by superficial telangiectasias in a unilateral distribution. Vascular endothelial growth factor (VEGF) may play a role in the pathogenesis of UNTS in patients with underlying hepatic disease. We report a case of a patient with UNTS accompanied by chronic hepatitis C virus infection, with a normal serum estrogen profile and strong positive immunohistochemical staining of lesional skin with VEGF.

Prevalence of Chlamydia trachomatis and Mycoplasma genitalium in pregnant women of Sabzevar-Iran.

BACKGROUND: As prenatal screening for sexually transmitted infections and treatment of infected pregnant women is not routinely performed in Iran and prevalence of two sexually transmitted pathogens, Chlamydia trachomatis and Mycoplasma genitalium, in Sabzevar (east of Iran) is unknown, we decided to perform this prospective study. METHODS: One hundred ninety-six urine specimens of pregnant women attending the specialized maternity hospital of the city were collected and tested by duplex PCR. RESULTS: A total of 31 specimens were positive (15.81%) (27 Chlamydia trachomatis isolates, 13.77%; and 2 Mycoplasma genitalium isolates, 1.02%). Co-infection with both species was detected in 2 specimens (1.02%). A significant correlation was found between preterm labor and infection (P-value ≤ 0.05). CONCLUSION: The present study shows high prevalence of Chlamydial infections in comparison with Mycoplasma genitalium in this region. Further studies with larger sample size and more focused on different groups at risk are needed for a movement towards prevention and control of sexually transmitted infections (STIs).

Adrenergic signaling in human oral keratinocytes and wound repair.

Catecholamines are present in saliva, but their influence on oral epithelium is not understood. Because psychological stress increases salivary catecholamines and impairs oral mucosal wound healing, we sought to determine if epithelial adrenergic signaling could link these two findings. We found that cultured human oral keratinocytes (HOK) express the α(2B)- and ß(2)-adrenergic receptors (ARs). Exposure of HOK to either epinephrine or the ß-AR agonist, isoproterenol, reduced migratory speed and decreased in vitro scratch wound healing. Incubation with the ß-AR antagonist timolol reversed the catecholamine-induced effects, indicating that the observed response is mediated by ß-AR. Epinephrine treatment decreased phosphorylation of the mitogen-activated protein kinases (MAPK) ERK1/2 and p38; these decreases were also reversed with timolol. Cultured HOK express enzymes of the epinephrine synthetic pathway, and generate epinephrine. These findings demonstrate that stress-induced elevations of salivary catecholamines signal through MAPK pathways, and result in impaired oral keratinocyte migration required for healing.

Azimuthal instability of the interface in a shear banded flow by direct visual observation.

The stability of the shear banded flow of a Maxwellian fluid is studied from an experimental point of view using rheology and flow visualization with polarized light. We show that the one-layer homogeneous flow cannot sustain shear rates corresponding to the end of the stress plateau. The high shear rate branch is not found and the shear stress oscillates at the end of the plateau. An azimuthal instability appears: the shear induced band becomes unstable and the interface between the two bands undulates in time and space with a period τ, a wavelength λ and a wave vector k parallel to the direction of the tangential velocity.

Clinical, histopathologic, and molecular aspects of cutaneous human papillomavirus infections.

Human papillomaviruses comprise a large family of double stranded DNA viruses that are the etiologic agents of benign warts and anogenital cancers. At least 82 different human papillomavirus types have been identified and many remain yet uncharacterized. The development of new molecular techniques in recent years has led to an increased understanding of human papillomaviruses and their roles in carcinogenesis. Several clinicopathologic entities arising from human papillomavirus infection encountered by the dermatologist are the subject of the article. The epidemiology, molecular biology, clinical presentation, histologic findings, and treatment of each disorder, where applicable, is discussed.

Enhanced fluctuations in small phospholipid bilayer vesicles containing cholesterol.

Ultrasonic and calorimetric studies of small homogeneously-sized DMPC unilamellar vesicles showed two thermal transitions at temperatures Tc1 and Tc2 (Tc2 greater than or equal to Tc1); Tc2 is close to the phase transition temperature, Tc, of large vesicles. The process at Tc2 is not a fusion of vesicles and is interpreted as characterizing an order-disorder transition essentially similar to that of large vesicles. The temperatures Tc1 and Tc2 become increasingly similar as the cholesterol content is increased, while the clusters at Tc2 (congruent to 85 lipid molecules in pure DMPC) increase in size up to approximately 180 lipid molecules at 12 mol% cholesterol. Incorporation of cholesterol thus brings about enhanced fluctuations in this model system of a membrane.