Digital Photomicrography Research Articles

Open-source Smartphone Adapter in Digital Photomicrography.

Background and aim:Smartphones can be used to capture images from the microscope. There are commercial and homemade adapters that can be used to overcome the difficulty of focusing on a smartphone camera. We conducted this study to test if the usage of a homemade adapter reduces the time and effort of the operator in comparison to the free-hand technique in smartphone photomicrography.Materials and Methods:We made a simple smartphone adapter for digital photomicrography. Thirty-two operators first captured the image on the smartphone with the free-hand technique and then with the adapter thrice from a microscope. The time for focusing was compared statistically by paired t-test. A survey was conducted to know operators's opinions on adapter-assisted photomicrography.Result:All the participants were able to capture images from the microscopes. The average time for focusing with adapter was (11.89 ± 4.19 seconds) significantly (P = 0.0001) lower than the free-hand technique (25.56±11.81 seconds). However, the images yielded from both techniques were of equal quality. The majority of the participant found the method to be easy and reduce their effort in focusing and capturing an image.Conclusion:Low-cost homemade smartphone adapter helps in reducing the time required for capturing an image from the microscope. It decreases the effort of the operator in comparison to the free-hand technique. Hence, it may be a good choice for those who need to capture images from the microscopes frequently for either telemedicine or research purpose in resource-limited settings.

Identifying and Quantifying the Difference between Adenomatous Colon Polyps and Normal Colon Tissue from Clinical Histological Images

This study aimed to evaluate automated image analysis as a tool for differentiating normal tissue from adenomatous polyp lesions. Images of colon surgical pathology samples from 140 patients (70 normal subjects and 70 polyp subjects) were captured on a personal computer using an Olympus DP20 digital photomicrography apparatus mounted on an Olympus light microscope (trinocular) at 1200×1800 dots per inch resolution, with the high power magnification of ×400. The complexity of image patterns was studied. In particular, image features of Fractal Dimension (FD) and Lacunarity (Lac) were extracted by using non-overlapping and sliding box-counting techniques. There were highly significant differences between the two clinical groups for both techniques, with polyp images in comparison with normal tissue images having significantly greater FD (1.83±0.04 v 1.73±0.08 p<0.0001) and significantly smaller Lac (0.28±0.08 v 0.42±0.12 p<0.0001) by using the non-overlapping box-counting method, and similar results by using the sliding box-counting method (1.86±0.09 v 1.78±0.08 p<0.0001, and 0.26±0.08 v 0.37±0.12 p<0.0001, respectively). These results encourage the use of computer automation, as normal colon tissue and adenomatous polyp tissue can be significantly differentiated

Two cases reports comparing histopathological features of canine transmissible venereal tumor after treatment with decimal potencies of Viscum Album and Vincristin

The aim of the study was to evaluate the histopathological features of two canine transmissible venereal tumor (TVT) cases: one treated with Viscum album (Q) protocol in serial decimal potencies and the other with Vincristin conventional protocol (treated control). Tumor infiltrating leukocytes pattern and apoptosis were analyzed quantitatively, using a computer image analysis system, twice: before the beginning of treatment and after six weeks. Both female dogs were sujected to weekly clinical evaluation for three months, focusing on tumor remission and eventual adverse effects manifestations (local or systemic). In both the cases, animals had a round cells tumor growth, with weak intercellular stroma connection, typical of a TVT mass. The lysozyme positivity in immunohistochemistry analysis, associated with typical morphology confirmed the diagnosis. Ten fields were randomly photographed by a digital photomicrography system NIKON Eclipse 2 – Coolpix. Each captured image was analyzed quantitatively by the Metamorph® software, considering the number of leukocyte infiltrated and mitosis per field. Caspase 3 positivity index was also evaluated. In Vincristin treated dog, the number of leukocytes infiltrating tumor was bigger than that found in Viscum album treated dog, even before the beginning of the treatment, indicating an initial conditions compatible to a more favorable prognosis, however, the number of leukocytes increased in the Viscum album treated dog during the observation period (Kruskal Wallis, p < 0.05). The animal treated with Vincristine has no statistical significant variation in the number of infiltrating mononuclear cells during the treatment, but presented 10 times more mitotic figures (Kruskal Wallis, p < 0.001) in the second biopsy, compared to the other stages of treatment. There was a statistical significant increase in the rate of positivity for Caspase 3 between biopsies taken before and after treatment with Viscum album (ANOVA, p=0.01), but not after Vincristin treatment. Even though, the tumor remission could be achieved only in Vincristin treated dog, with an abrupt reduction of mitosis number and tumor mass in the last 20 days of treatment. In contrast, a secondary infection of the tumor led to clinical worsening of TVT in Viscum album treated dog, which could explain the increase in the local leukocytes number. The increase in Caspase 3 positivity after treatment shows the Viscum album anti-neoplastic mechanism of action, but in this case it was not enough to reach a complete tumor remission.

Comparative Anatomy of the Mammalian Corneal Subbasal Nerve Plexus.

PurposeThe subbasal nerve plexus (SNP) is the densest and most recognizable component of the mammalian corneal innervation; however, the anatomical configuration of the SNP in most animal models remains incompletely described. The purpose of the current study is to describe in detail the SNP architecture in eight different mammals, including several popular animal models used in cornea research.MethodsCorneal nerves in mouse, rat, guinea pig, rabbit, dog, macaque, domestic pig, and cow eyes were stained immunohistochemically with antiserum directed against neurotubulin. SNP architecture was documented by digital photomicrography and large-scale reconstructions, that is, corneal nerve maps, using a drawing tube attached to a light microscope.ResultsSubbasal nerve fibers (SNFs) in mice, rats, guinea pigs, dogs, and macaques radiated centrally from the corneoscleral limbus toward the corneal apex in a whorl-like or spiraling pattern. SNFs in rabbit and bovine corneas swept horizontally across the ocular surface in a temporal-to-nasal direction and converged on the inferonasal limbus without forming a spiral. SNFs in the pig cornea radiated centrifugally in all directions, like a starburst, from a focal point located equidistant between the corneal apex and the superior pole.ConclusionsThe results of the present study have demonstrated for the first time substantial interspecies differences in the architectural organization of the mammalian SNP. The physiological significance of these different patterns and the mechanisms that regulate SNP pattern formation in the mammalian cornea remain incompletely understood and warrant additional investigation.

New Insight into Hellenistic and Roman Cypriot Wall Paintings: An Exploration of Artists’ Materials, Production Technology, and Technical Style

A recent scientific investigation on Hellenistic and Roman wall paintings of funerary and domestic contexts from Nea (‘New’) Paphos, located in the southwest region of Cyprus, has revealed new information on the paintings’ constituent materials, their production technology and technical style of painting. Nea Paphos, founded in the late 4th century BC, became the capital of the island during the Hellenistic period (294–58 BC) and developed into a thriving economic center that continued through the Roman period (58 BC–330 AD). A systematic, analytical study of ancient Cypriot wall paintings, excavated from the wealthy residences of Nea Paphos and the surrounding necropoleis, combining complementary non-invasive, field-deployable characterization techniques, has expanded the scope of analysis, interpretation and access of these paintings. The results from in situ analyses, combining X-ray fluorescence (XRF) and fiber-optic reflectance spectroscopy (FORS), forensic imaging in reflectance and luminescence, and digital photomicrography, were informative on the raw materials selection, application technique(s) and extent of paintings beyond the visible. Data collected through the integration of these techniques were able to: (1) show an intricate and rich palette of pigments consisting of local and foreign natural minerals and synthetic coloring compounds applied pure or in mixtures, in single or multiple layers; (2) identify and map the spatial distribution of Egyptian blue across the surface of the paintings, revealing the extent of imagery and reconstructing iconography that was no longer visible to the naked eye; and (3) visualize and validate the presence of Egyptian blue to delineate facial contours and flesh tone shading. This innovation and technical characteristic in the manner of painting facial outlines and constructing chiaroscuro provides a new insight into the artistic practices, inferring artists/or workshops’ organization in Cyprus during the Roman period.

Which mode and potency of electrocoagulation yields the Smallest Unobstructed Area of the Fallopian Tubes?

To determine which mode and potency of electrocoagulation, using a modern electrosurgical generator, yields the smallest unobstructed area of the Fallopian tubes. In an experimental study, tubes from 48 hysterectomies or tubal ligation were evaluated. Tubes were randomly allocated to one of the following groups: group A) 25 W x 5 seconds (n = 17); group B) 30 W x 5 seconds (n = 17); group C) 35 W x 5 seconds (n = 18), group D) 40 W x 5 seconds (n = 20); group E) 40 W x 5 seconds with visual inspection (blanch, swells, collapse) (n = 16); group F) 50 W x 5 seconds (n = 8). Bipolar electrocoagulation was performed in groups A to E, and monopolar electrocoagulation was performed in group F. Coagulation mode was used in all groups. Digital photomicrography of the transversal histological sections of the isthmic segment of the Fallopian tube were taken, and the median percentage of unobstructed luminal area (mm2) was measured with ImageJ software (ImageJ, National Institutes of Health, Bethesda, MD, USA). The Kruskal-Wallis test or analysis of variance (ANOVA) was used for statistical analysis. Ninety-six Fallopian tube sections were analyzed. The smallest median occluded area (%; range) of the Fallopian tube was obtained in the group with 40 W with visual inspection (8.3%; 0.9-40%), followed by the groups 25 W (9.1%; 0-35.9%), 40 W (14.2; 0.9-43.2%), 30 W (14.2; 0.9-49.7%), 35 W (15.1; 3-46.4%) and 50 W (38.2; 3.1-51%). No statistically significant difference was found among groups (p = 0.09, Kruskal-Wallis test). The smallest unobstructed area was obtained with power setting at 40 W with visual inspection using a modern electrosurgical generator. However, no statistically significant difference in the unobstructed area was observed among the groups using these different modes and potencies.

Development of a Simple Smartphone Adapter for Digital Photomicrography.

Development of a Simple Smartphone Adapter for Digital Photomicrography.

Corrigendum.

Journal of Cutaneous PathologyVolume 43, Issue 8 p. 727-727 CorrigendumFree Access Corrigendum This article corrects the following: High-quality digital photomicrography utilizing a smartphone without adapter Cheng Zhou, Yan Yu, Ruzeng Xue, Dirk M. Elston, Volume 43Issue 1Journal of Cutaneous Pathology pages: 82-84 First Published online: August 17, 2015 First published: 18 July 2016 https://doi.org/10.1111/cup.12761AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL In our brief communication, High-quality digital photomicrography utilizing a smartphone without adapter (J Cutan Pathol. 2015 Aug 17. doi: 10.1111/cup.12561) we noted that Bellina, et al. first reported the use of a similar technique to send high quality photomicrographs from isolated laboratories to obtain expert opinions.1 Morrison and Gardner also published a similar technique and produced a YouTube tutorial that demonstrated a stabilization technique essentially the same as what we used to obtain images through our dissecting microscope.2 (https://www.youtube.com/watch?v=PHQX5I7EXE) Graff, et al. also reported a similar technique.3 References 1Bellina L, Missoni E. Mobile cell-phones (M-phones) in telemicroscopy: increasing connectivity of isolated laboratories. Diagnostic Pathology 2009; 4: 19. 2Morrison AS, Gardner JM. Smart Phone Microscopic Photography: A Novel Tool for Physicians and Trainees. Arch Pathol Lab Med 2013; 138: 1002. 3Graff JP, Wu ML. The Nokia Lumia 1020 smartphone as a 41-megapixel photomicroscope. Histopathology, June 2014; 64: 1044. ePub: Febrary 14, 2014 DOI: 10.1111/his.12355. Volume43, Issue8August 2016Pages 727-727 ReferencesRelatedInformation

Testing an Alternative Method for Estimating the Length of Fungal Hyphae Using Photomicrography and Image Processing.

This study aimed to develop and test an unbiased and rapid methodology to estimate the length of external arbuscular mycorrhizal fungal (AMF) hyphae in soil. The traditional visual gridline intersection (VGI) method, which consists in a direct visual examination of the intersections of hyphae with gridlines on a microscope eyepiece after aqueous extraction, membrane-filtration, and staining (e.g., with trypan blue), was refined. For this, (i) images of the stained hyphae were taken by using a digital photomicrography technique to avoid the use of the microscope and the method was referred to as “digital gridline intersection” (DGI) method; and (ii), the images taken in (i) were processed and the hyphal length was measured by using ImageJ software, referred to as the “photomicrography–ImageJ processing” (PIP) method. The DGI and PIP methods were tested using known grade lengths of possum fur. Then they were applied to measure the hyphal lengths in soils with contrasting phosphorus (P) fertility status. Linear regressions were obtained between the known lengths (Lknown) of possum fur and the values determined by using either the DGI (LDGI) (LDGI = 0.37 + 0.97 × Lknown, r2 = 0.86) or PIP (LPIP) methods (LPIP = 0.33 + 1.01 × Lknown, r2 = 0.98). There were no significant (P > 0.05) differences between the LDGI and LPIP values. While both methods provided accurate estimation (slope of regression being 1.0), the PIP method was more precise, as reflected by a higher value of r2 and lower coefficients of variation. The average hyphal lengths (6.5–19.4 m g–1) obtained by the use of these methods were in the range of those typically reported in the literature (3–30 m g–1). Roots growing in P-deficient soil developed 2.5 times as many hyphae as roots growing in P-rich soil (17.4 vs 7.2 m g–1). These tests confirmed that the use of digital photomicrography in conjunction with either the grid–line intersection principle or image processing is a suitable method for the measurement of AMF hyphal lengths in soils for comparative investigations.

Pathogenesis of Plantar Epidermal Cyst: Three-Dimensional Reconstruction Analysis.

Pathogenesis of Plantar Epidermal Cyst: Three-Dimensional Reconstruction Analysis.

Digital Photomicrography for Gemologists

Digital Photomicrography for Gemologists

Deus está nos detalhes. Ouro, prata e policromia

A policromia visível de uma escultura em madeira representando S. João Evangelista, do Museu Nacional de Arte Antiga, Lisboa (Portugal) apresenta várias técnicas que se com-plementam na criação de um sumptuoso estofado. Este caso de estudo permitiu o exame de processos de douramento, prateamento e policromia, sendo as observações da sua execução reportadas e documentadas com os resultados de uma abordagem multi-analítica. O exame incluiu fotomicrografia digital e observação de cortes transversais de amostras de policromia, recorrendo a identificação material a vários métodos analíticos, incluindo microscopia eletrónica de varrimento associada a espectroscopia raios-X por dispersão de energia (SEM-EDS) e difração de raios-X (XRD).

Pathomorphological differentiation between traumatic rupture and nontraumatic arterial dissection of the intracranial vertebral artery

We aimed to establish an objective indicator for differential diagnosis between traumatic rupture of the intracranial vertebral artery (TRIVA) and nontraumatic rupture from intracranial vertebral artery dissection (NIVAD). We investigated 19 intracranial vertebral artery (IVA) samples, including three from TRIVA, seven from NIVAD and nine non-IVA rupture cases using 0.2-mm serial histological sections through the IVA. The internal elastic lamina (IEL)-adventitia ratio for each slide was calculated as the ratio of the traced length of the adventitia to the length of the IEL as measured by digital photomicrography. NIVAD cases showed a significant peak in the IEL-adventitia ratio around the area of rupture, whereas TRIVA and non-rupture cases showed no specific increase or decrease in IEL-adventitia ratios throughout the IVAs. All NIVAD cases had a significantly higher average IEL-adventitia ratio across 10 slides at the site of the rupture lesion than at the site furthest from the rupture. In contrast, two out of three TRIVA cases showed no significant difference between the two points. The other TRIVA case showed a significantly lower IEL-adventitia ratio at the point nearest the rupture compared with that at the point farthest from the rupture. Other histological characteristics considered specific to either TRIVA or NIVAD were observed. Our results indicate that measuring and comparing IEL-adventitia ratios at ruptured and non-ruptured sites of the IVA could be a useful practical indicator for differential diagnosis between TRIVAs and NIVADs.

Smartphone adapters for digital photomicrography

Background: Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. Materials and Methods: We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom) were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. Results: All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Conclusions: Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs.

Emulsion graft polymerization of 4-chloromethylstyrene on kenaf fiber by pre-irradiation method

The stability of micelle size in 3% 4-chloromethylstyrene (CMS), 0.3% Tween 20 in water emulsion over time was studied using a static light scattering. It was found that the micelle diameter decreased with storage time and temperature. The influence of micelle size over time was then explored by adjusting the ratio of CMS to Tween 20 (10:1, 10:2, 10:4) at CMS concentration of 0.2–5.0%. It was found that the increase in average micelle diameter resulted in a decreased in the stability of CMS emulsion. Graft polymerization of CMS on kenaf fiber was carried out in emulsion with 350nm micelle at various CMS concentrations at a dose of 150kGy. It was found that the degree of grafting (Dg) was strongly dependent on the monomer concentration and time. However, the increase in micelles diameter from 250nm to 500nm resulted in the increased in Dg from 3% to 153%. This extraordinary result led us to investigate the micelle size distributions of CMS emulsion during graft polymerization. It was found that the diameter of micelle decreased rapidly to 100nm within 2h. It was discovered from digital photomicrography the existence of multiple emulsions in the CMS emulsion. It was proposed that the enhancement of grafting yield is governed by emulsion breakdown mechanisms through radical effect during radiation induced graft polymerization.

Low extent bone marrow involvement in newly diagnosed follicular lymphoma: diagnosis and clinical correlates

Aims We examined follicular lymphoma (FL) bone marrow (BM) involvement: frequency of low extent involvement, comparison of direct area measurement and a descriptive grading system and flow cytometry performance. We also assessed clinical predictors and clinical impact of FL BM status. Methods 151 consecutive initial staging BM biopsies were reviewed. Area assessment used digital photomicrography of one biopsy level and outlining intertrabecular spaces and FL infiltrates (AxioVision 7.4). A descriptive grading system proposed by Groupe d’Etudes Lymphomes Folliculaires (GELF) was applied. Results 63/151 (42%) BM were positive. Area measurement in 34 positive biopsies found area Discussion Low extent BM involvement is common in FL, without consensus guidelines for staging purposes. This has implications for the individual (stage, prognostic risk) and in clinical trial interpretation (population risk, complete response rate). The prognostic significance of low extent involvement for rituximab treated cohorts is unknown. The descriptive GELF grade, validated in this series, provides a reproducible tool suitable for prospectively addressing this question.

Low extent bone marrow involvement in newly diagnosed follicular lymphoma: diagnosis and clinical correlates

<h3>Aims</h3> We examined follicular lymphoma (FL) bone marrow (BM) involvement: frequency of low extent involvement, comparison of direct area measurement and a descriptive grading system and flow cytometry performance. We also assessed clinical predictors and clinical impact of FL BM status. <h3>Methods</h3> 151 consecutive initial staging BM biopsies were reviewed. Area assessment used digital photomicrography of one biopsy level and outlining intertrabecular spaces and FL infiltrates (AxioVision 7.4). A descriptive grading system proposed by Groupe d'Etudes Lymphomes Folliculaires (GELF) was applied. <h3>Results</h3> 63/151 (42%) BM were positive. Area measurement in 34 positive biopsies found area <1% in 7/34 (21%) and 1–10% in 14/34 (41%). GELF grade correlated with measured extent and showed excellent inter-observer reproducibility. Flow cytometry sensitivity, 59% overall (relative to histology), reduced to 29% when BM area was <1%. <h3>Discussion</h3> Low extent BM involvement is common in FL, without consensus guidelines for staging purposes. This has implications for the individual (stage, prognostic risk) and in clinical trial interpretation (population risk, complete response rate). The prognostic significance of low extent involvement for rituximab treated cohorts is unknown. The descriptive GELF grade, validated in this series, provides a reproducible tool suitable for prospectively addressing this question.

Theta Rotation and Serial Registration of Light Microscopical Images Using a Novel Camera Rotating Device

An electromechanical video camera coupler was developed to rotate a light microscope field of view (FOV) in real time without the need to physically rotate the stage or specimen. The device, referred to as the Camera Thetarotator, rotated microscopical views 240 degrees to assist microscopists to orient specimens within the FOV prior to image capture. The Camera Thetarotator eliminated the effort and artifacts created when rotating photomicrographs using conventional graphics software. The Camera Thetarotator could also be used to semimanually register a dataset of histological sections for three-dimensional (3D) reconstruction by superimposing the transparent, real-time FOV to the previously captured section in the series. When compared to Fourier-based software registration, alignment of serial sections using the Camera Thetarotator was more exact, resulting in more accurate 3D reconstructions with no computer-generated null space. When software-based registration was performed after prealigning sections with the Camera Thetarotator, registration was further enhanced. The Camera Thetarotator expanded microscopical viewing and digital photomicrography and provided a novel, accurate registration method for 3D reconstruction. The Camera Thetarotator would also be useful for performing automated microscopical functions necessary for telemicroscopy, high-throughput image acquisition and analysis, and other light microscopy applications.

RGB-Splitting and Multi-Shot Techniques in Digital Photomicrography—Utilization of Astronomic RGB-Filters in True Color Imaging

Abstract A great many filters in common use in astronomy are used in order to improve the resulting optical quality in observations and photographs [1-4]. The majority of these filters are also capable of improving image quality in microscopy and photomicrography. Several instances of this have already been reported in this magazine [5-6]. Some new types of RGB-CCD astro filters have recently been developed for multi-shot techniques [2]. These filters can also be regarded as interesting tools for photomicrography that can maximize the quality of true color imaging based on RGB-splitting and multi-shot techniques. The respective methods and their technical benefit are presented and discussed below. RGB-splitting and multi-shot techniques are routine tools in some fields of professional studio photography and astronomical photography. They can lead to visible improvements in sharpness, resolution and color balance. To obtain maximum image quality, special multi-shot cameras can be used. These are fitted with a multi-shot sensor that does not require any color filters. Therefore, each pixel is sensitive for all colors and pixel interpolations are not necessary.

Expression of stromal cell-derived factor 1 is increased in the retina of experimental diabetic rats

To investigate the expression of stromal cell-derived factor 1 (SDF-1) in retina of experimental diabetic rats. Thirty four healthy male Wistar rats of six to eight weeks old were chosen and divided randomly into 3 groups: normal control (CON, n = 8), diabetes mellitus 2 months (DM2M, n = 14) and 3 months (DM3M, n = 12). Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) (60 mg/kg). At the end point, immunochemistry and digital photomicrography analysis were employed to localize and quantitate the expression of SDF-1 in the retinas. The ratios of integrated optical density (IOD) to area of interest (AOI) were calculated to evaluate the intensities of positive staining. Values of z and t, as well as P value of each, were determined by Wilcoxon-Mann-Whitney test and Student's t-test, respectively. Immunofluorescent double-staining was used to indicate the co-expression of SDF-1 and hypoxia-inducible factor-1 (HIF-1), a pivotal transcription factor activated by hypoxia. The SDF-1 mRNA of the retina from DM2M (n = 4) and CON (n = 2) was detected by real-time RT-PCR. Copies of SDF-1 mRNA were then adjusted by the copies of beta-actin mRNA in each sample. Differences between groups were compared by a Student's t test. Positive immunohistochemical staining for SDF-1 was found in each group, most of which located in the inner part of the retina, especially at the inner nuclear layer (INL) and ganglion cell layer (GCL). The inter-quartile range of IOD/AOI of SDF-1 was between 0.6 x 10(-2) to 1.5 x 10(-2) in diabetic group, and 1.1 x 10(-3) to 2.4 x 10(-3) in control group (z = -3.359, P < 0.001). There was no significant difference between DM2M and DM3M (t = 0.952, P > 0.05). Co-expression of SDF-1 and HIF-1 was found in some cells in the inner part of the retina of diabetic rats. Copies of SDF-1 mRNA in DM2M were 2.3 x 10(-4) +/- 1.2 x 10(-4), and those in CON were 2.9 x 10(-4) +/- 1.0 x 10(-4). The ratios of them to beta-actin were 3.3 x 10(-2) +/- 8.5 x 10(-3) for DM2M and 1.7 x 10(-2) +/- 5.7 x 10(-3) for CON (t = 2.33, P < 0.05). Possibly promoted by HIF-1, expression of SDF-1 is increased in the retinas of diabetic rats, which may play an important role in the mechanism of diabetic retinopathy.