H Uusitalo

University of Tampere, Tammerfors, Province of Western Finland, Finland

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Publications (183)403.79 Total impact

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    ABSTRACT: PurposeChronic conjunctival inflammation, caused by various reasons, for example long-term use of topical drugs and/or their preservatives, affects the outcome of glaucoma surgery by interfering with wound healing. Matrix metalloproteinases (MMPs) remodel extracellular matrix (ECM) and are involved in the wound healing process. This study was designed to evaluate the conjunctival expression of MMPs and their tissue inhibitors (TIMPs) in the normal eye, primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG) and whether there is an association between staining intensities and deep sclerectomy outcome.Methods Immunohistochemical procedures were performed on conjunctival samples which were obtained from POAG (n = 11) and ExG (n = 14) patients as well as normal (n = 7) subjects. Antibodies against MMPs (MMP-1, -2, -3 and -9) and TIMPs (TIMP-1, -2 and -3) were used.ResultsIn conjunctival stroma, expression levels of MMP-2 (p = 0.047), MMP-3 (p = 0.009), MMP-9 (p < 0.001), TIMP-1 (p = 0.003), TIMP-2 (p < 0.001) and TIMP-3 (p < 0.001) in ExG and MMP-9 (p = 0.008), TIMP-2 (p = 0.02) and TIMP-3 (p = 0.002) in POAG were significantly increased compared to control. We further found correlations between expression of MMP-1 and MMP-3 and the length of pilocarpine treatment.Conclusion The expression of MMPs and TIMPs is increased in the conjunctiva of POAG and ExG patients having a long history of topical antiglaucoma drops. Antiglaucoma agents and/or their preservatives alter the remodelling balance of ECM in conjunctiva of POAG and ExG eyes. The balance between MMPs and TIMPs may play a crucial role in the conjunctival wound healing process and the outcome of glaucoma surgery.
    Acta ophthalmologica 10/2014; · 2.44 Impact Factor
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    ABSTRACT: Human induced pluripotent stem cells (hiPSCs) offer unique opportunities for developing novel cell-based therapies and disease modeling. In this study, we developed a directed differentiation method for hiPSCs toward corneal epithelial progenitor cells capable of terminal differentiation toward mature corneal epithelial-like cells. In order to improve the efficiency and reproducibility of our method, we replicated signaling cues active during ocular surface ectoderm development with the help of two small-molecule inhibitors in combination with basic fibroblast growth factor (bFGF) in serum-free and feeder-free conditions. First, small-molecule induction downregulated the expression of pluripotency markers while upregulating several transcription factors essential for normal eye development. Second, protein expression of the corneal epithelial progenitor marker p63 was greatly enhanced, with up to 95% of cells being p63 positive after 5 weeks of differentiation. Third, corneal epithelial-like cells were obtained upon further maturation.
    Stem cell reports. 02/2014; 2(2):219-31.
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    ABSTRACT: To examine the general health status and health-related quality of life (HRQOL) along the diabetes continuum of middle-aged and older Finns, and to determine the glucose metabolism stage by which the HRQOL has decreased noticeably. The cross-sectional sample consisted of 920 persons aged 51-75 from the general population in a single municipality in a rural area of Eastern Finland. Data were adjusted for age, sex, smoking history, current alcohol consumption, employment and marital status. The HRQOL and health status were evaluated using two preference-based HRQOL instruments, 15D and SF-6D, and one health profile instrument, 36-Item Short Form Health Survey (SF-36). Individuals with impaired glucose tolerance (IGT) and type 2 diabetes had noticeably low mean SF-6D, 15D and general health status. The decrease in overall HRQOL was mainly due to a decline in the physical dimensions of HRQOL. The adjusted odds ratios (95 % CI) for having noticeably low HRQOL on SF-6D, 15D and general health dimension of SF-36 associated with IGT were 1.95 (1.18-3.25), 1.35 (0.84-2.18) and 2.00 (1.21-3.29), respectively. The progression along the diabetes continuum was significantly associated with a decrease in HRQOL and health status. Furthermore, the data indicate that when a person is detected to have IGT, the HRQOL and general health status have already diminished noticeably. The prevailing evidence suggests that detection and intervention before a patient develops IGT is essential in order to minimize the loss of quality of life and quality-adjusted life years.
    Quality of Life Research 02/2014; · 2.86 Impact Factor
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    ABSTRACT: To present the outcomes of laser-assisted in situ keratomileusis (LASIK) operations performed with the new three-dimensional, transportable FEMTO LDV Z6 I femtosecond laser (Ziemer Ophthalmic Systems, Port, Switzerland) and the Allegretto Wave Concerto 500 Hz excimer laser (Wavelight AG, Erlangen, Germany) in terms of accuracy, reproducibility and safety of flap creation. This is a retrospective study of 309 consecutive eyes of 160 patients treated with the FEMTO LDV Z6 I for corneal flap creation. The target flap thickness was 90 μm. The size of the suction ring varied from 9.5 to 10.0 mm and target flap diameter from 9.3 to 9.6 mm, respectively. The target hinge length was 4.0 mm. The FEMTO LDV Z6 I produced the 90-μm targeted flaps very consistently (mean 90.1 ± 2.7 μm, range 78-100). Mean flap diameter with the 9.3-mm target flap diameter was 9.3 ± 0.1 mm (range 9.0-9.6) and with the 9.6-mm target flap diameter 9.6 ± 0.1 mm (range 9.0-9.8). Mean hinge length was 3.9 ± 0.1 mm (range 3.3-4.2). Minor complications were reported in 15 (5%) eyes, but none of them prevented refractive laser treatment. The most common complications were bubbles in the conjunctiva (n = 7, 2%) and an opaque bubble layer inside the flap margin (n = 6, 2%). None of the eyes lost two Snellen lines of corrected distance visual acuity during 1-month follow-up. In the hands of an experienced surgeon, the transfer from the Classic FEMTO LDV to Z6 I was a safe and straight forward process yielding accurate and reproducible flaps.
    Acta ophthalmologica 12/2013; · 2.44 Impact Factor
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    ABSTRACT: Extracellular matrix (ECM) interactions play a vital role in cell morphology, migration, proliferation and differentiation of cells. We investigated the role of ECM proteins to the structure and function of human embryonic stem cell derived retinal pigment epithelial (hESC-RPE) cells during their differentiation and maturation from hESCs into RPE cells in adherent differentiation cultures on several human ECM proteins found in native human Bruch's membrane namely collagen I, collagen IV, laminin, fibronectin, vitronectin, as well as on commercial substrates of xeno-free CELLstartTM and MatrigelTM. Cell pigmentation, expression of RPE specific proteins, fine structure as well as the production of basal lamina by hESC-RPE on different protein coatings were evaluated after 140 days of differentiation. The integrity of hESC-RPE epithelium and barrier properties on different coatings were investigated by measuring transepithelial resistance. All coatings supported the differentiation of hESC-RPE cells as demonstrated by early onset of cell pigmentation and further maturation to RPE monolayers after enrichment. Mature RPE phenotype was verified by RPE specific gene and protein expression, correct epithelial polarization and phagocytic activity. Significant differences were found in the degree of RPE cell pigmentation and tightness of epithelial barrier between different coatings. Furthermore, the thickness of self-assembled basal lamina and secretion of the key ECM proteins found in the basement membrane of the native RPE varied between hESC-RPE cultured on compared protein coatings. In conclusion, this study shows that the cell culture substrate has a major effect on the structure and basal lamina production during the differentiation and maturation of hESC-RPE potentially influencing the success of cell integrations and survival after cell transplantation.
    Tissue Engineering Part A 09/2013; · 4.64 Impact Factor
  • Juha Välimäki, Hannu Uusitalo
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    ABSTRACT: To detect by immunohistochemical means the changes in bleb capsules at the cellular level between functioning and non-functioning glaucoma drainage implants (GDIs). Three samples each of functioning (1 Baerveldt and 2 Molteno implants) and non-functioning filtration blebs (1 Molteno and 2 Ahmed implants) were studied. A non-functioning bleb was defined as an intra-ocular pressure (IOP) >21 mmHg or a <20% reduction in IOP from baseline on three consecutive follow-up visits with maximal tolerated medication. The capsules were obtained between 6 and 108 months after GDI insertion for medical reasons only. Primary antibodies were used to stain fibronectin, tenascin, laminin, collagen IV and smooth muscle actin (SMA). The samples were graded on the basis of the intensity and quantity of immunohistochemical staining into four categories as follows: no staining or a mild, moderate or marked staining. The non-functioning blebs expressed more fibronectin, tenascin and SMA through the whole capsule wall than the functioning blebs. In the functioning blebs, tenascin was found mainly in the inner layer of the capsule. More type IV collagen and laminin were also found in the non-functioning bleb capsules than in the functioning blebs. No difference was found between the bleb capsules irrespective of whether they had been perfused with aqueous humour immediately after surgery (Ahmed) or after a delay (Molteno, Baerveldt). Accumulation of extracellular matrix components and activated fibroblasts in the bleb capsules of non-functioning GDI indicates the presence of an active wound healing process, suggesting a possible reduction in filtration through the bleb wall.
    Acta ophthalmologica 09/2013; · 2.44 Impact Factor
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    ABSTRACT: PURPOSE: The aim of the study is to examine the health-related quality-of-life (HRQOL) impact of the nocturnal awakenings and the duration of the sleep in the Finnish middle-aged and older population. METHODS: Cross-sectional sample consisted of 823 community-dwelling persons aged 55-75 living in a single municipality in a rural area of Eastern Finland. Frequency of the nocturnal awakenings was dichotomized as reporting "frequent," if the participant reported subjectively awakening "often" or "very often," and "infrequent" if the participant reported awakening "sometimes" or less frequently. HRQOL was measured with a preference-based HRQOL-index instrument, 15D. Analyses were adjusted for gender, BMI, morbidities, depression, employment and marital status, current smoking and drinking, exercise, recommendation to exercise from a health care professional, and subjective opinion about own exercise habits. RESULTS: Frequent nocturnal awakenings had statistically and clinically significant negative impact on HRQOL, the mean (SE) adjusted marginal HRQOL impact being -0.0416 (0.006). More than 10 and less than 6.5 h of daily sleep were associated with higher probability of having low HRQOL, adjusted odd ratios (95 % CI) being 2.65 (1.11-6.33) and 2.65 (1.55-4.52), respectively. However, the changes in daily sleep duration did not have noticeable influence on the significance or magnitude of the negative HRQOL impact of the frequent nocturnal awakenings. CONCLUSIONS: Nocturnal awakenings displayed a strong independent association with decreased HRQOL. The findings suggest that both clinicians and researchers should pay closer attention to nocturnal awakenings and other sleep problems in order to find ways to improve the quality of life in individuals with such conditions.
    Quality of Life Research 04/2013; · 2.86 Impact Factor
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    ABSTRACT: PURPOSE: Aquaporins (AQPs), a family of transmembrane water channel proteins, are essential for allowing passive water transport through retinal pigmented epithelial (RPE) cells. Even though human native RPE cells and immortalized human RPEs have been shown to express AQPs, the expression of AQPs during the differentiation in stem cell-derived RPE remains to be elucidated. METHODS: In human embryonic (hESCs) and induced pluripotent stem cells (hiPSCs)-derived RPE cells, the expression of several AQPs was determined by quantitative real-time PCR and the localization of AQP1 was assessed with confocal microscopy. The functionality of AQP water channels was determined by cell volume assay in hESC-derived RPE cells. RESULTS: AQP1, AQP3, AQP4, AQP5, AQP6, AQP7, AQP10, AQP11, and AQP12 were expressed in hESC- and hiPSC-derived RPE cells. Furthermore, the expression of AQP1 and AQP11 genes were significantly upregulated during the maturation of both hESC and iPSC into RPE. Confocal microscopy shows the expression of AQP1 at the apical plasma membrane of polarized cobblestone hESC- and hiPSC-derived RPE cells. Lastly, aquaporin inhibitors significantly reduced AQP functionality in hESC-RPE cells. CONCLUSIONS: hESC-RPE and hiPSC-RPE cells express several AQP genes, which are functional in mature hESC-derived RPE cells. The localization of AQP1 on the apical plasma membrane in mature RPE cells derived from both hESC and hiPSC suggests its functionality. These data propose that hESC- and hiPSC-derived RPE cells, grown and differentiated under serum-free conditions, resemble their native counterpart in the human eye.
    Investigative ophthalmology & visual science 01/2013; 54(5):3510-3519. · 3.43 Impact Factor
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    ABSTRACT: The aim of this study was to characterize the ocular morphology of low-density lipoprotein receptor-deficient apolipoprotein B-100-only mice, where overexpression of insulin-like growth factor II (IGF-II) has been shown to induce glucose intolerance and increase atherosclerotic lesion progression and calcification. Fifteen-month-old mice were examined on a normal chow diet and after 3 months of a high-fat Western diet. IGF-II-negative LDLR(-/-)ApoB(100/100) littermates and C57Bl/6J mice served as controls. In vivo color images of the fundi were obtained, and eyes were processed either for retinal flat mounts for assessment of neovascularization or for paraffin-embedded samples for immunohistochemical analyses. IGF-II overexpression and the resulting prediabetic phenotype did not induce microvascular damage when assessed in fundus photographs and retinal whole mounts, and the number of capillaries in IGF-II/LDLR(-/-)ApoB(100/100) mice was not significantly different from LDLR(-/-)ApoB(100/100) mice. However, morphology of the inner nuclear, outer plexiform, and outer nuclear layers was altered in the IGF-II/LDLR(-/-)ApoB(100/100) mice. Moreover, photoreceptor atrophy and thinning of the outer nuclear layer were present. Caspase-3 staining was positive in the photoreceptor inner segment. In addition, retinas of the IGF-II/LDLR(-/-)ApoB(100/100) mice displayed reduced rhodopsin positivity, consistent with the decreased number of photoreceptor cells. This study reports a novel form of retinopathy with photoreceptor atrophy and abundant changes in retinal morphology in a mouse model of prediabetes and atherosclerosis.
    Molecular vision 01/2013; 19:1723-33. · 1.99 Impact Factor
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    ABSTRACT: We address the performance evaluation practices for developing medical image analysis methods, in particular, how to establish and share databases of medical images with verified ground truth and solid evaluation protocols. Such databases support the development of better algorithms, execution of profound method comparisons, and, consequently, technology transfer from research laboratories to clinical practice. For this purpose, we propose a framework consisting of reusable methods and tools for the laborious task of constructing a benchmark database. We provide a software tool for medical image annotation helping to collect class label, spatial span, and expert's confidence on lesions and a method to appropriately combine the manual segmentations from multiple experts. The tool and all necessary functionality for method evaluation are provided as public software packages. As a case study, we utilized the framework and tools to establish the DiaRetDB1 V2.1 database for benchmarking diabetic retinopathy detection algorithms. The database contains a set of retinal images, ground truth based on information from multiple experts, and a baseline algorithm for the detection of retinopathy lesions.
    Computational and Mathematical Methods in Medicine 01/2013; 2013:368514. · 0.79 Impact Factor
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    ABSTRACT: We address performance evaluation practices for developing medical image analysis methods, and contribute to the practice to establish and to share databases of medical images with verified ground truth and solid evaluation protocols. This helps to develop better algorithms, to perform profound method comparisons, including the state-of-the-art methods, and consequently, supports technology transfer from research laboratories to clinical practice. For this purpose, we propose a framework consisting of reusable methods and tools for the laborious task of constructing a benchmark database. We provide a medical image annotation software tool which helps to collect and store ground truth for retinopathy lesions from experts, including the fusion of spatial annotations from several experts. The tool and all necessary functionality for method evaluation are provided as a public software package. For demonstration purposes, we utilise the framework and tools to establish the DiaRetDB1 V2.1 database for benchmarking diabetic retinopathy detection algorithms. The database contains a set of retinal images, ground truth from several experts, and a strawman algorithm for the detection of retinopathy lesions.
    Proceedings of the third Sino-foreign-interchange conference on Intelligent Science and Intelligent Data Engineering; 10/2012
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    ABSTRACT: Purpose:  Ocular surface reconstruction with cultivated oral mucosal epithelial transplantation technique is a viable treatment option for severe ocular surface injuries and diseases with limbal stem cell deficiency. Currently, this technique is based on utilization of xenogenic, allogenic or undefined components such as murine 3T3 feeders, serum and amniotic membrane. In this study, we aimed to find a more defined culture method to generate stratified human oral mucosal epithelium. Methods:  In this study, we have examined the formation of stratified cell sheets from human oral mucosal epithelial cells under serum-free culture environment both in the absence and presence of fibroblast-conditioned culture medium and elevated epidermal growth factor (EGF) concentration. Results:  In all examined culture conditions, the cultivated oral epithelial cells formed a stratified tissue, which was positive for keratins K3/12, K4 and K13. The tissue-engineered oral epithelia also expressed proliferation and progenitor markers Ki67 and p63 in the basal layer of the cell sheets, suggesting that the epithelia still had regenerative capacity. The cultures presented expression of tight junction proteins ZO-1 and occludin and high transepithelial electrical resistance values. Conclusion:  In this culture method, we have been able to produce stratified cell sheets successfully without serum, conditioning of the medium or increased EGF concentration. We provide a novel protocol to produce tight multi-layered epithelium with proliferative potential, which can be easily adapted for cultivated oral mucosal epithelial transplantation.
    Acta ophthalmologica 09/2012; · 2.44 Impact Factor
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    ABSTRACT: The in vitro generation of a functional retinal pigment epithelium (RPE) for therapeutic applications requires a limitless source of RPE cells and a supporting scaffold, which improves cell survival and promotes the acquisition of the RPE phenotype. We successfully differentiated human embryonic stem cells (hESCs) toward RPE on a transplantable, biopolymer coated polyimide (PI) membrane. We studied various membrane coatings of which several lead to the generation of a tight and highly polarized epithelium having typical characteristics and functions of human RPE. The cells established a distinctive hexagonal, cobblestone morphology with strong pigmentation, expressed RPE specific genes and proteins, and phagocytosed photoreceptor outer segments (POS) after co-culture with rat retinal explants. The barrier function of hESC-derived RPE (hESC-RPE) monolayers was confirmed by transepithelial electrical resistance and permeability measurements. In conclusion, we show that the PI biomembrane is a suitable scaffold for hESC-RPE tissue engineering.
    Biomaterials 08/2012; 33(32):8047-54. · 8.31 Impact Factor
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    ABSTRACT: BACKGROUND: The aim of this paper is to present the accuracy, predictability, and safety outcomes of LASIK enhancements performed with the FEMTO LDV femtosecond laser (Ziemer Ophthalmic Systems, Port, Switzerland) and the Allegretto Wave Concerto 500 Hz excimer laser (Wavelight AG, Erlangen, Germany), following previous LASIK treatments. METHODS: FEMTO LDV was used for flap creation in 85 previously LASIK-treated eyes of 62 patients. The intended flap thickness was 90 μm in 81 eyes and 140 μm in 4 eyes. The size of the suction ring was 9.0 mm in 72 eyes and 9.5 mm in 13 eyes. Flap dimensions were measured and correlated to preoperative characteristics. RESULTS: With the intended flap thickness of 90 μm in previously LASIK-treated eyes, the actual flap thickness was 90.2 ± 6.6 μm (range 80-122), and the flap diameter was 9.2 ± 0.2 mm (range 8.7-9.9). The mean hinge length was 4.0 ± 0.2 mm (range 3.0-4.8). Flap thickness correlated positively with patient age and hinge length. Complications were reported in 12 eyes (14.1 %). Most of the complications were very mild, and none of them prevented further refractive laser treatment. One eye lost two Snellen lines of best spectacle-corrected visual acuity. CONCLUSIONS: Femtosecond LASIK enhancement is warranted only in rare cases. Surgical experience is needed and special caution must be practiced. For cases of a primary free cap, femtosecond LASIK is not recommended.
    Albrecht von Graæes Archiv für Ophthalmologie 07/2012; · 1.93 Impact Factor
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    Acta ophthalmologica 05/2012; · 2.44 Impact Factor
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    Clinical and experimental rheumatology 03/2012; 30(3):456-7. · 2.66 Impact Factor
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    ABSTRACT: To investigate the cytotoxicity of benzalkonium chloride (BAC)-containing ophthalmic solutions of prostaglandin analogs (latanoprost, travoprost, bimatoprost, and preservative-free (PF) tafluprost), BAC mixture (BACmix) and BAC homologs with different alkyl chain lengths using human corneal epithelial (HCE) and conjunctival epithelial (IOBA-NHC) cell cultures. The distribution of BAC homologs in rabbit ocular surface tissues in vivo was examined. The cells were exposed for one hour to prostaglandin analogs, BACmix and three homologs. Cytotoxicity was assessed with the WST-1 and lactate dehydrogenase (LDH) assays for cellular viability and cell membrane integrity. BAC 0.02% solution was instilled on the rabbit eye daily for 14 days and the concentrations of BAC homologs in external ocular tissues were determined. The order of decreasing cytotoxicity in the WST-1 test was latanoprost ≥ travoprost > bimatoprost ≥ PF tafluprost. IOBA-NHC cells were more sensitive than HCE cells. In HCE, only latanoprost diluted to 10% increased LDH leakage. In IOBA-NHC, LDH leakage was statistically significant with 3-10% travoprost and 10% latanoprost. The order of decreasing cytotoxicity of preservatives was C14 > C12 > BACmix > C16 in HCE and C12 > C14 > BACmix > C16 in IOBA-NHC. Following treatment with BAC 0.02% solution, the amounts of BAC-C12, -C14 and -C16 in rabbit cornea and conjunctiva, respectively were: 0.37 ± 0.08 and 2.64 ± 0.27 ng/mg; 0.42 ± 0.07 and 4.77 ± 0.43 ng/mg; 0.04 ± 0.01 and 0.54 ± 0.05 ng/mg. The cytotoxic effects of latanoprost, travoprost, and bimatoprost were dependent on the BAC concentration in their formulations. BACmix was cytotoxic at the concentrations above those corresponding to 0.001% BAC in ophthalmic medications. PF tafluprost was the least toxic of the drugs tested. Within studied BAC homologs, those with longer alkyl chain and higher lipophility penetrated effectively into rabbit external ocular tissues.
    Current eye research 11/2011; 37(2):145-54. · 1.51 Impact Factor
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    ABSTRACT: To investigate the conjunctival inflammatory alterations of patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (ExG) and correlate the findings with the success of deep sclerectomy (DS) surgery and with the patients' medical history. Altogether 25 POAG and ExG patients of the prospective DS study were divided, based on the diagnosis and success of the operation, into 4 groups, POAG S (success), POAG F (failure), ExG S, and ExG F. Controls were obtained from other ophthalmologic surgery patients who did not have glaucoma, and their conjunctiva was examined to be normal. Inflammatory cell subtypes in the conjunctiva were identified and quantified by using immunohistochemistry and monoclonal antibodies: CD3 (T-lymphocyte marker), CD4 (T-helper lymphocyte marker), CD8 (T-cytotoxic lymphocyte marker), CD20 (pan-B cell marker), CD38 (plasma cell marker), CD45RA (naïve T-cell marker), and CD68 (macrophage marker). Higher numbers of inflammatory cells were found in the conjunctiva of the glaucoma patients on medical treatment compared with the normal conjunctiva of the controls. Moreover, T-lymphocytes, T-helper lymphocytes, T-cytotoxic lymphocytes, B cells, plasma cells, and macrophages were found in significantly higher numbers in patients in whom DS failed during the follow-up period of 2.5 years than those with surgical success. High numbers of cytotoxic and helper T-lymphocytes, plasma cells, and macrophages indicate a chronic inflammatory reaction in the conjunctiva of glaucoma patients. The chronic inflammation is most probably owing to the chronic topical treatment of the patients and seems to be a significant risk factor for DS surgery failure.
    Journal of glaucoma 03/2011; 20(3):172-8. · 1.74 Impact Factor
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    ABSTRACT: Retinal pigment epithelial (RPE) cells are continually exposed to oxidative stress that contributes to protein misfolding, aggregation and functional abnormalities during aging. The protein aggregates formed at the cell periphery are delivered along the microtubulus network by dynein-dependent retrograde trafficking to a juxtanuclear location. We demonstrate that Hsp90 inhibition by geldanamycin can effectively suppress proteasome inhibitor, MG-132-induced protein aggregation in a way that is independent of HDAC inhibition or the tubulin acetylation levels in ARPE-19 cells. However, the tubulin acetylation and polymerization state affects the localization of the proteasome-inhibitor-induced aggregation. These findings open new perspectives for understanding the pathogenesis of protein aggregation in retinal cells and can be useful for the development of therapeutic treatments to prevent retinal cell deterioration.
    BioMed Research International 01/2011; 2011:798052. · 2.71 Impact Factor
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    ABSTRACT: Biomaterials are widely used in ophthalmology, and biodegradable polymers have been evaluated for use in surgery, tissue engineering and targeted drug delivery. We examined the tissue reactions attributable to 3 biodegradable polymers in the rat eye. Inion GTR™ membrane [a blend of 85:15 poly(L-lactide-coglycolide) and 70:30 poly(L-lactide-co-1,3-trimethylene carbonate) copolymers in a molar ratio of 70:30], a 50:50 molar ratio of poly(DL-lactide-coglycolide) (PDLGA 50:50), and a 85:15 molar ratio of poly(DL-lactide-coglycolide) (PDLGA 85:15) were surgically implanted into the subconjuctival space of rat eyes. Biocompatibility was evaluated by following the eyes clinically and with histo- and immunohistochemical techniques. No clinical signs of inflammation were observed around the implants during follow-up. However, immunohistochemical sections revealed increased accumulation of magrophages around PDLGA 85:15 at 2 weeks and of myofibroblasts around GTR membrane material at 1 month. The order of the degradation time of the material was GTR membrane material > PDLGA 85:15 > PDLGA 50:50; Fourier transform infrared microscopy revealed some differences in the degradation behavior of the polymers. Immunohistochemical staining for plasma or cellular fibronectin was observed around all implants. Despite the different decay times and influences on the expression levels of fibronectins, all polymers evoked rather similar tissue reactions during the observation period. This study provides new data on the biocompatibility of biomaterials in rat eyes. Our findings of the tissue decay of the implant and biomaterial-induced tissue reaction may help in the development of better biomaterials for eye surgery with optimal drug delivery properties.
    Ophthalmic Research 01/2011; 46(2):55-65. · 1.56 Impact Factor

Publication Stats

2k Citations
403.79 Total Impact Points

Institutions

  • 1994–2014
    • University of Tampere
      • • Department of Ophthalmology
      • • Institute of Biomedical Technology
      • • Regea Institute for Regenerative Medicine
      • • Medical School
      Tammerfors, Province of Western Finland, Finland
  • 2013
    • Päijät-Hämeen Central Hospital
      Lahti, Southern Finland Province, Finland
  • 2009–2012
    • Tampere University Hospital (TAUH)
      Tammerfors, Province of Western Finland, Finland
    • University Hospital Linköping
      Linköping, Östergötland, Sweden
  • 2005–2012
    • Mehiläinen Group
      Helsinki, Southern Finland Province, Finland
  • 1983–2012
    • University of Helsinki
      • • Centre for Drug Research (CDR)
      • • Department of Anatomy
      • • Institute of Biomedicine
      • • Department of Clinical Chemistry
      Helsinki, Province of Southern Finland, Finland
  • 2011
    • University of Eastern Finland
      • Institute of Clinical Medicine
      Joensuu, Province of Eastern Finland, Finland
  • 2003–2011
    • University of Kuopio
      • Department of Ophthalmology
      Kuopio, Eastern Finland Province, Finland
  • 2010
    • Azienda Ospedaliera Universitaria San Martino di Genova
      Genova, Liguria, Italy
  • 1984–2009
    • Helsinki University Central Hospital
      • Department of Ophthalmology
      Helsinki, Southern Finland Province, Finland
  • 2007
    • Helsinki School of Economics
      Helsinki, Southern Finland Province, Finland
  • 2004–2007
    • Kuopio University Hospital
      • Department of Ophthalmology
      Kuopio, Province of Eastern Finland, Finland
  • 1998–2005
    • University of Turku
      • • Department of Medical Biochemistry and Genetics
      • • Department of Surgery
      Turku, Western Finland, Finland
    • Santen
      Tammerfors, Province of Western Finland, Finland