Thickness of the cervical epithelium of autopsied patients with acquired immunodeficiency syndrome

Polarization-sensitive optical coherence tomography with a conical beam scan for the investigation of birefringence and collagen alignment in the human cervix

By measuring the phase retardance of a cervical extracellular matrix, our in-house polarization-sensitive optical coherence tomography (PS-OCT) was shown to be capable of (1) mapping the distribution of collagen fibers in the non-gravid cervix, (2) accurately determining birefringence, and (3) measuring the distinctive depolarization of the cervical tissue. A conical beam scan strategy was also employed to explore the 3D orientation of the collagen fibers in the cervix by interrogating the samples with an incident light at 45° and successive azimuthal rotations of 0-360°. Our results confirmed previous observations by X-ray diffraction, suggesting that in the non-gravid human cervix collagen fibers adjacent to the endocervical canal and in the outermost areas tend to arrange in a longitudinal fashion whereas in the middle area they are oriented circumferentially. PS-OCT can assess the microstructure of the human cervical collagen in vitro and holds the potential to help us better understand cervical remodeling prior to birth pending the development of an in vivo probe.

Skin aging in patients with acquired immunodeficiency syndrome

To evaluate the histomorphometric skin changes over aging patients with autopsied acquired immunodeficiency syndrome (AIDS). In 29 skin fragments of autopsied elderly (older than 50 years) and nonelderly patients with AIDS, epidermal thickness, the number of layers, the diameter of cells, the percentage of collagen and elastic fibers in the dermis, and the number and morphology of Langerhans cells were assessed. Statistical analysis was performed by SigmaStat 2.03 program. The thickness of the epidermis (92.55 × 158.94 μm), the number of layers (7 × 9 layers), and the diameter of the cells (13.27 × 17.6 μm) were statistically lower among the elderly. The quantity of collagen fibers (9.68 × 14.11%) and elastic fibers (11.89 × 15.31%) was also significantly lower in the elderly. There was a decrease in total (10.61 × 12.38 cel/mm(2)) and an increase in immature Langerhans cells (6.31 × 4.98 cel/mm(2)) in elderly patients with AIDS. The aging of the skin of patients with AIDS is amended in different histomorphometric aspects, the epidermis constituents suffer less pronounced changes in normal aging, and the dermis has more intense changes in elastic fibers and collagen.

Characterization of thin poly(dimethylsiloxane)-based tissue-simulating phantoms with tunable reduced scattering and absorption coefficients at visible and near-infrared wavelengths

Optical phantoms are used in the development of various imaging systems. For certain applications, the development of thin phantoms that simulate the physical size and optical properties of tissue is important. Here, we demonstrate a method for producing thin phantom layers with tunable optical properties using poly(dimethylsiloxane) (PDMS) as a substrate material. The thickness of each layer (between 115 and 880 μm) was controlled using a spin coater. The reduced scattering and absorption coefficients were controlled using titanium dioxide and alcohol-soluble nigrosin, respectively. These optical coefficients were quantified at six discrete wavelengths (591, 631, 659, 691, 731, and 851 nm) at varying concentrations of titanium dioxide and nigrosin using spatial frequency domain imaging. From the presented data, we provide lookup tables to determine the appropriate concentrations of scattering and absorbing agents to be used in the design of PDMS-based phantoms with specific optical coefficients. In addition, heterogeneous phantoms mimicking the layered features of certain tissue types may be fabricated from multiple stacked layers, each with custom optical properties. These thin, tunable PDMS optical phantoms can simulate many tissue types and have broad imaging calibration applications in endoscopy, diffuse optical spectroscopic imaging, and optical coherence tomography, etc.

Oral epithelial changes in HIV-positive individuals

HIV infections frequently affect the oral cavity, and local changes may be utilized as indicators of immunosuppression in HIV-positive patients. Morphometric and morphological features of the lining, masticatory, and specialized epithelium of the oral mucosa were studied in 12 HIV-positive and 12 HIV-negative patients autopsied from 2007 to 2010. Mucosal samples from the cheek, gingival, and tongue of 24 individuals were fixed in Carnoy solution and stained with hematoxylin-eosin. Various morphometric characteristics (epithelial thickness, number of cell layers, mean cell diameter) and morphological parameters (basal layer hyperplasia, exocytosis of inflammatory cells, glycogenic acanthosis, cell ballooning degeneration) were then measured. The HIV-positive group had a greater epithelial thickness (mean: 304.4μm) and a higher mean cell diameter (11.84μm), whereas the HIV-negative group had more epithelial layers (26.7). Basal layer hyperplasia did not differ significantly between the two groups, but exocytosis of inflammatory cells, glycogenic acanthosis, cell ballooning, and spongiosis were more prevalent in the HIV-positive group. Our findings demonstrate that HIV infection causes diverse epithelial changes in the oral cavity, including thickening, increased cell diameter, increased migration of inflammatory cells, and inter- and intra-cellular edema.

Optical coherence tomography for assessment of microbicide safety in a small animal model

Sensitive imaging techniques for small animals are needed to assess drug toxicity in preclinical studies. Optical coherence tomography (OCT) provides a noninvasive tool for high-resolution, depth-resolved visualization of drug-induced changes in tissue morphology. In a mouse model, we utilize OCT to assess vaginal tissue integrity following the application of topical microbicides (drugs used to prevent infection). Mice are challenged with herpes simplex virus-2 (HSV-2) to determine the correlation of tissue damage as quantified by OCT to increased susceptibility. The microbicide benzalkonium chloride (BZK) (0.02, 0.2, or 2%) or phosphate buffered saline control is administered intravaginally. In vivo OCT imaging and collection of tissue samples are performed after treatment. A quantitative OCT scoring system is applied to assess epithelial damage, and the results are compared with those of histology. A separate group of mice are treated similarly then challenged with HSV-2. Epithelial morphology quantified noninvasively by OCT and histology are dose-dependent (p<0.0001). The OCT scoring system detected a significant increase in epithelial damage with increasing BZK concentration (p<0.0001). These results paralleled an increase in HSV-2 susceptibility (p<0.005). OCT can be used as a noninvasive tool to assess topical drug toxicity in a small animal model with potential to predict increased susceptibility to vaginal infection.

Analysis of the scalp of women with AIDS subjected to autopsy: epithelial, follicular, and immunologic aspects

Hair keeps the scalp warmer and slightly moister than the rest of the skin, which contributes to a favorable environment for mycotic, bacterial, and parasitic infections. It is well established that AIDS makes the patient more susceptible to opportunistic infections and cutaneous manifestations. Because of this, the aim of this study was to analyze scalp fragments of autopsied women with AIDS. Twenty-eight scalp samples of women aged between 18 and 46 years were observed. These women were divided into 2 groups: with AIDS (n = 14) and without AIDS (n = 14). We conducted histochemical (hematoxylin-eosin, Picrosirius, and Verhoeff), morphometric (Image J; National Institutes of Health, Hamilton, ON, Canada and KS-300 Kontron-Zeiss; Kontron Elektronik, Carl-Zeiss, Germany), and immunohistochemical (S-100) analyses of the scalp. In patients with AIDS, epithelial thickness, number of epithelial cell layers, number of immature Langerhans cells in the epidermis, and percentages of elastic fibers in the dermis were significantly lower, whereas telogen hair follicles were significantly higher. The percentage of collagen fibers in the dermis and the diameter of the epithelial cells were smaller in patients with AIDS, without significant difference. AIDS possibly causes immunologic and morphologic alterations in the scalp. This study may establish parameters for better clinical and morphologic diagnostic in patients with AIDS.

Morphological and immunological changes in the skin of autopsied women with AIDS

Acquired immunodeficiency syndrome (AIDS) is characterized by decreased immunity, making a patient more susceptible to opportunistic infections which can have cutaneous manifestations. The aim of this study was to evaluate the local immunity of the skin through morphological and immunohistochemical analysis. Skin samples of 52 women, 27 without AIDS and 25 with AIDS, autopsied in an academic referral hospital in Brazil were evaluated. The autopsy reports and medical records were reviewed, and histochemical Hematoxylin-eosin, Picrosirius red, and Verhoeff stains as well as morphometric (Image J and KS-300 Kontron-Zeiss) and immunohistochemical (S-100 and anti-IgA) analyses of the skin were performed. Women with AIDS presented a thinner epidermis than women without AIDS (33.33 [12.00-317.66] vs 67.42 [12.00-530.02] μm; p < 0.001), with a lower number of epithelial cell layers (4.00 [2.00-11.00] vs 4.00 [2.00-16.00]; p < 0.001), a smaller cell diameter (12.92 [6.00-28.87] vs 24.32 [6.00-33.12] μm; p < 0.001), and a lower number of Langerhans cells (LC) (12.58 [0.00-81.74] vs 31.44 [0.00-169.77] LC/mm(2); p < 0.001). The dermis contained more collagen fibers (8.20 % [2.40-19.40] vs 6.30 % [0.40-13.90]; p < 0.001). Some of these parameters were negatively correlated with viral load and positively correlated with the number of CD4+ T-lymphocytes. We conclude that a decrease of the local skin immunity in women with AIDS may contribute to the development of skin lesions.

Towards a field-compatible optical spectroscopic device for cervical cancer screening in resource-limited settings: effects of calibration and pressure

Quantitative optical spectroscopy has the potential to provide an effective low cost, and portable solution for cervical pre-cancer screening in resource-limited communities. However, clinical studies to validate the use of this technology in resource-limited settings require low power consumption and good quality control that is minimally influenced by the operator or variable environmental conditions in the field. The goal of this study was to evaluate the effects of two sources of potential error: calibration and pressure on the extraction of absorption and scattering properties of normal cervical tissues in a resource-limited setting in Leogane, Haiti. Our results show that self-calibrated measurements improved scattering measurements through real-time correction of system drift, in addition to minimizing the time required for post-calibration. Variations in pressure (tested without the potential confounding effects of calibration error) caused local changes in vasculature and scatterer density that significantly impacted the tissue absorption and scattering properties Future spectroscopic systems intended for clinical use, particularly where operator training is not viable and environmental conditions unpredictable, should incorporate a real-time self-calibration channel and collect diffuse reflectance spectra at a consistent pressure to maximize data integrity.

The influence of gender and of AIDS on the immunity of autopsied patients' esophagus

Previous studies have shown that males who have AIDS are more frequently affected by infectious diseases than females. The esophagus is the organ in the digestive tube that is more commonly affected by opportunistic infections during the syndrome. The aim of this study was to assess the influence of AIDS and of gender on local immunity of the esophageal epithelium. Fragments of the esophagus from 29 autopsied women and 37 autopsied men were collected at a university hospital from 1980 to 2009 and were divided in groups with and without AIDS. The IgA-, IgG-, and IgM-positive cells and Langerhans cells (LCs) were immunostained, respectively, with anti-IgA, anti-IgG, anti-IgM, and anti-S100. The software Image J was used to measure the esophageal epithelium and to count the epithelium cellular layers. Patients with AIDS, apart from gender, showed an increase in IgA-, IgG-, and IgM-positive cells and a reduction of Langerhans cells, in thickness and in number of cellular layers in the esophageal epithelium. However, among individuals with AIDS, men presented lower secretory expression of IgA-, IgG-, and IgM-positive cells than women and more intense reduction of LCs. Women have naturally presented better local esophageal immunity than men. Although AIDS possibly causes immunological and morphological alterations in the esophageal epithelium in both genders, women have better esophageal immunity, which may explain a greater frequency of hospital admissions due to infection of men with AIDS when compared with women.

Visible light optical spectroscopy is sensitive to neovascularization in the dysplastic cervix

Neovascularization in cervical intraepithelial neoplasia (CIN) is studied because it is the precursor to the third most common female cancer worldwide. Diffuse reflectance from 450-600 nm was collected from 46 patients (76 sites) undergoing colposcopy at Duke University Medical Center. Total hemoglobin, derived using an inverse Monte Carlo model, significantly increased in CIN 2+ (N=12) versus CIN 1 (N=16) and normal tissues (N=48) combined with P<0.004. Immunohistochemistry using monoclonal anti-CD34 was used to quantify microvessel density to validate the increased hemoglobin content. Biopsies from 51 sites were stained, and up to three hot spots per slide were selected for microvessel quantification by two observers. Similar to the optical study results, microvessel density was significantly increased in CIN 2+ (N=16) versus CIN 1 (N=21) and normal tissue (N=14) combined with P<0.007. Total vessel density, however, was not significantly associated with dysplastic grade. Hence, our quantitative optical spectroscopy system is primarily sensitive to dysplastic neovascularization immediately beneath the basement membrane, with minimal confounding from vascularity inherent in the normal stromal environment. This tool could have potential for in vivo applications in screening for cervical cancer, prognostics, and monitoring of antiangiogenic effects in chemoprevention therapies.

Esophageal epithelium of women with AIDS: thickness and local immunity

The aim of this study was to evaluate the morphological characteristics of the esophageal epithelium (EE) and its local immunity. Esophageal fragments of autopsied women were collected from 1980 to 2008, and two groups were analyzed: with AIDS (n=17) and without AIDS (n=12). The measurement of the esophageal epithelium was carried out through the image analysis software ImageJ, and the immunostaining of Langerhans cells (LCs) was carried out using anti-S100 antibody. Women with AIDS, when compared with women without AIDS, had significantly thinner EE (220.6 versus 243.5 microm), a less number of LCs (6.2 versus 18.8 LCs/mm(2)), and a higher percentage of immature or morphologically altered LCs (66.6 versus 40.0%). The malnourished women, when compared with normonourished women, regardless of AIDS, had significantly thinner EE (227.1 versus 238.0 microm) and a less number of LCs (6.2 versus 12.5 LCs/mm(2)). The percentage of immature or morphologically altered LCs was the same in both groups. Additionally, the women with AIDS (7.0 versus 2.8%) and the malnourished women (5.8 versus 3.1%) presented a significantly higher percentage of fibrosis. We concluded that AIDS and malnutrition contribute to the decrease in esophagus local immunity and, therefore, to a possible increase in local opportunistic infections.