Bone Marrow Stromal Cells Promote Innervation of Bioengineered Teeth.

Transplantation of bone marrow mesenchymal stem cells (BMDCs) into a denervated side of the spinal cord was reported to be a useful option for axonal regeneration. The innervation of teeth is essential for their function and protection but does not occur spontaneously after injury. Cultured reassociations between dissociated embryonic dental mesenchymal and epithelial cells and implantation lead to a vascularized tooth organ regeneration. However, when reassociations were coimplanted with a trigeminal ganglion (TG), innervation did not occur. On the other hand, reassociations between mixed embryonic dental mesenchymal cells and bone marrow-derived cells isolated from green fluorescent protein (GFP) transgenic mice (BMDCs-GFP) (50/50) with an intact and competent dental epithelium (ED14) were innervated. In the present study, we verified the stemness of isolated BMDCs, confirmed their potential role in the innervation of bioengineered teeth, and analyzed the mechanisms by which this innervation can occur. For that purpose, reassociations between mixed embryonic dental mesenchymal cells and BMDCs-GFP with an intact and competent dental epithelium were cultured and coimplanted subcutaneously with a TG for 2 wk in ICR mice. Axons entered the dental pulp and reached the odontoblast layer. BMDCs-GFP were detected at the base of the tooth, with some being present in the pulp associated with the axons. Thus, while having a very limited contribution in tooth formation, they promoted the innervation of the bioengineered teeth. Using quantitative reverse transcription polymerase chain reaction and immunostainings, BMDCs were shown to promote innervation by 2 mechanisms: 1) via immunomodulation by reducing the number of T lymphocytes (CD3+, CD25+) in the implants and 2) by expressing neurotrophic factors such as NGF, BDNF, and NT3 for axonal growth. This strategy using autologous mesenchymal cells coming from bone marrow could be used to innervate bioengineered teeth without treatment with an immunosuppressor such as cyclosporine A (CsA), thus avoiding multiple side effects.

A Third Type of Resistance to Cydia pomonella Granulovirus in Codling Moths Shows a Mixed Z-Linked and Autosomal Inheritance Pattern.

Different isolates of Cydia pomonella granulovirus (CpGV) are used worldwide to control codling moth larvae (Cydia pomonella) in pome fruit production. Two types of dominantly inherited field resistance of C. pomonella to CpGV have been recently identified: Z-chromosomal type I resistance and autosomal type II resistance. In the present study, a CpGV-resistant C. pomonella field population (termed SA-GO) from northeastern Germany was investigated. SA-GO individuals showed cross-resistance to CpGV isolates of genome group A (CpGV-M) and genome group E (CpGV-S), whereas genome group B (CpGV-E2) was still infective. Crossing experiments between individuals of SA-GO and the susceptible C. pomonella strain CpS indicated the presence of a dominant autosomal inheritance factor. By single-pair inbreeding of SA-GO individuals for two generations, the genetically more homogenous strain CpRGO was generated. Resistance testing of CpRGO neonates with different CpGV isolates revealed that isolate CpGV-E2 and isolates CpGV-I07 and -I12 were resistance breaking. When progeny of hybrid crosses and backcrosses between individuals of resistant strain CpRGO and susceptible strain CpS were infected with CpGV-M and CpGV-S, resistance to CpGV-S appeared to be autosomal and dominant for larval survivorship but recessive when success of pupation of the hybrids was considered. Inheritance of resistance to CpGV-M, however, is proposed to be both autosomal and Z linked, since Z linkage of resistance was needed for pupation. Hence, we propose a further type III resistance to CpGV in C. pomonella, which differs from type I and type II resistance in its mode of inheritance and response to CpGV isolates from different genome groups.IMPORTANCE The baculovirus Cydia pomonella granulovirus (CpGV) is registered and applied as a biocontrol agent in nearly all pome fruit-growing countries worldwide to control codling moth caterpillars in an environmentally friendly manner. It is therefore the most widely used commercial baculovirus biocontrol agent. Since 2005, field resistance of codling moth to CpGV products has been observed in more than 40 field plantations in Europe, threatening organic and integrated apple production. Knowledge of the inheritance and mechanism(s) of resistance is indispensable for the understanding of host response to baculovirus infection on the population level and the coevolutionary arms race between virus and host, as well as for the development of appropriate resistance management strategies. Here, we report a codling moth field population with a new type of resistance, which appears to follow a highly complex inheritance in regard to different CpGV isolates.

[Prognosis and treatment of macular bleeding in neovascular age-related macular degeneration]. / Prognose und Behandlung makulärer Blutungen bei neovaskulärer altersabhängiger Makuladegeneration.

Macular bleeding is associated with an acute loss of visual function and is frequently a complication of neovascular age-related macular degeneration. Blood degradation products can lead to permanent retinal neuronal damage over time. The extent of the bleeding is correlated to the coagulation status of the patient. The treatment strategy depends on the age, size and exact location of the bleeding. The spectrum of therapeutic options ranges from watchful waiting to large scale vitrectomy with removal of subretinal mass bleeding.

Promoting bioengineered tooth innervation using nanostructured and hybrid scaffolds.

The innervation of teeth mediated by axons originating from the trigeminal ganglia is essential for their function and protection. Immunosuppressive therapy using Cyclosporine A (CsA) was found to accelerate the innervation of transplanted tissues and particularly that of bioengineered teeth. To avoid the CsA side effects, we report in this study the preparation of CsA loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles, their embedding on polycaprolactone (PCL)-based scaffolds and their possible use as templates for the innervation of bioengineered teeth. This PCL scaffold, approved by the FDA and capable of mimicking the extracellular matrix, was obtained by electrospinning and decorated with CsA-loaded PLGA nanoparticles to allow a local sustained action of this immunosuppressive drug. Dental re-associations were co-implanted with a trigeminal ganglion on functionalized scaffolds containing PLGA and PLGA/cyclosporine in adult ICR mice during 2weeks. Histological analyses showed that the designed scaffolds did not alter the teeth development after in vivo implantation. The study of the innervation of the dental re-associations by indirect immunofluorescence and transmission electron microscopy (TEM), showed that 88.4% of the regenerated teeth were innervated when using the CsA-loaded PLGA scaffold. The development of active implants thus allows their potential use in the context of dental engineering. STATEMENT OF SIGNIFICANCE: Tooth innervation is essential for their function and protection and this can be promoted in vivo using polymeric scaffolds functionalized with immunosuppressive drug-loaded nanoparticles. Immunosuppressive therapy using biodegradable nanoparticles loaded with Cyclosporine A was found to accelerate the innervation of bioengineered teeth after two weeks of implantation.

Evidence for a Second Type of Resistance against Cydia pomonella Granulovirus in Field Populations of Codling Moths.

Cydia pomonella granulovirus (CpGV) is an important biocontrol agent for the codling moth (CM) in organic and integrated apple production worldwide. Previously, Z chromosome-linked dominant resistance in at least 38 CM field populations in Europe was reported, threatening organic apple production. Growers responded by switching to a different resistance-breaking isolate of CpGV that could control these populations. Here, we report a nonuniform response of different CM field populations to CpGV isolates from CpGV genome groups A to E. Even more strikingly, one field population, NRW-WE, was resistant to all known CpGV genome groups except group B. Single-pair crossing experiments with a susceptible strain, followed by resistance testing of the F1 offspring, clearly indicated cross-resistance to CpGV isolates that had been considered to be resistance breaking. This finding provides clear evidence of a second, broader type of CpGV resistance with a novel mode of inheritance that cannot be fully explained by Z-linkage of resistance. IMPORTANCE: CpGV is registered and used in virtually all commercial apple growing areas worldwide and is therefore the most widely used baculovirus biocontrol agent. Recently, resistance to CpGV products was reported in different countries in Europe, threatening organic growers who rely almost exclusively on CpGV products. This resistance appeared to be targeted against a 24-bp repeat in the pe38 gene in isolate CpGV-M of genome group A, which had been used commercially for many years. On the other hand, resistance could be broken by CpGV isolates from CpGV genome groups B to E. Here, we report clear evidence of a second type of field resistance that is also directed against resistance-breaking isolates of CpGV genome groups C, D, and E and which appears not to be targeted against CpGV pe38 Therefore, we propose to differentiate between type I resistance, which is targeted against pe38 of CpGV genome group A, and a novel type II resistance with an unknown molecular target. This finding stresses the need for further adoption of resistance management strategies for CpGV, since growers cannot rely solely on the use of resistance-breaking CpGV isolates.

Three-dimensional Micro-culture System for Tooth Tissue Engineering.

The arrangement of cells within a tissue plays an essential role in organogenesis, including tooth development. Progress is being made to regenerate teeth by reassociating dissociated embryonic dental cells and implanting them in vivo. In the present study, we tested the hanging drop method to study mixed epithelial-mesenchymal cell reorganization in a liquid instead of semisolid medium to see whether it could lead to tooth histogenesis and organogenesis. This method allowed the control of the proportion and number of cells to be used, and the forming microtissues showed homogeneous size. The liquid environment favored cell migrations as compared with collagen gels. Three protocols were compared. The one that sequentially combined the hanging drop and semisolid medium cultures prior to in vivo implantation gave the best results. Indeed, after implantation, teeth developed, showing a well-formed crown, mineralization of dentin and enamel, and the initiation of root formation. Vascularization and the cellular heterogeneity in the mesenchyme were similar to what was observed in developing molars. Finally, after coimplantation with a trigeminal ganglion, the dental mesenchyme, including the odontoblast layer, became innervated. The real advantage of this technique is the small number of cells required to make a tooth. This experimental model can be employed to study the development, physiology, metabolism, or toxicology in forming teeth and test other cell sources.

[Retrospective investigation of anti-VEGF treatment reality and effectiveness in patients with neovascular age-related macular degeneration (AMD) in Germany: treatment reality of ranibizumab for neovascular AMD in Germany]. / Retrospektive Untersuchung der Anti-VEGF-Behandlungsrealität und Wirksamkeit bei Patienten mit neovaskulärer altersabhängiger Makuladegeneration (nAMD) in Deutschland : Behandlungsrealität von Ranibizumab bei nAMD in Deutschland.

BACKGROUND: Neovascular (wet) age-related macular degeneration (wAMD) is a progressive and degenerative retinal disease. This study reports the real-life use in Germany of the standard anti-vascular endothelial growth factor (VEGF) therapy for wAMD as an intravitreal operative drug application. PATIENTS AND METHODS: Within the framework of an international retrospective study the medical records of patients with wAMD who were first treated with ranibizumab between 1 January and 31 August 2009 were evaluated. Data were collected until the end of treatment and/or monitoring or until 31 August 2011. The primary objective was to evaluate changes in visual acuity after the start of anti-VEGF therapy. Secondary outcomes included determining real-life anti-VEGF treatment regimens and disease-monitoring practices. RESULTS: Out of 2227 patients who received ≥ 1 anti-VEGF injection with a baseline visual acuity assessment and ≥ 1 post-baseline visual acuity assessment for the treated eye, 420 were included in the German cohort. Visual acuity improved until about day 90 but these gains in visual acuity were not maintained. The mean changes in visual acuity scores from baseline to years 1 and 2 were 1.1 ± 15.7 and - 0.8 ± 17.2 letters, respectively. Patients received a mean of 4.3 ± 1.9 and 1.3 ± 2.2 injections in years 1 and 2, respectively. The majority of visits ( 98.6 %) were conducted irregularly and outside the time frame recommended at the time of the study, with an average of 47.7 ± 36.7 days between visits. More frequent visits and injections were associated with greater improvements in visual acuity. CONCLUSION: Treatment intensity was not sufficient to maintain the initial improvement in visual acuity by ranibizumab treatment. Real-life results for visual acuity and injection frequency in the German cohort were worse at that time than in other countries. Regular follow-up visits as well as timely retreatment in the presence of signs of disease activity are required to achieve optimal results in wAMD when applying a pro re nata-based strategy.

[Retinal Arterial Macroaneurysms (RAM)--pathology, differenzial diagnoses, and therapy]. / Retinale arterielle Makroaneurysmen (RAM)--Pathologie, Differenzialdiagnose und Therapie.

Retinal arterial macroaneurysms (RAM) are unilateral, solitary, acquired saccular or fusiform dilatations of the large arterioles of the retina, usually within the first three orders of bifurcation. They are associated with systemic vascular conditions such as hypertension and arteriosclerotic disease and occur most commonly in elderly women. Cases of simple RAM are predominated by the vascular ectasia. These macroaneurysms regress without treatment and without causing decreased visual acuity and will usually remain undetected. Complex RAM often go along with vision loss due to haemorrhage or oedema affecting the macula. Poor visual outcome may occur secondary to foveal exudates and subfoveal haemorrhage, the latter appear as pre-retinal, intra-, and subretinal haemorrhage. This overview discusses conservative and surgical therapeutic options for complex cases.

[Trauma-associated juvenile rhegmatogenous retinal detachment]. / Traumaassoziierte rhegmatogene Netzhautablösung im Kindesalter.

BACKGROUND: Rhegmatogenous retinal detachments (RRD) in children and adolescents are uncommon and present about 3-5 % of all retinal detachments. Etiology, pathogenesis and therapy differ significantly from adults. The current study addresses juvenile RRD after trauma to contribute to the limited knowledge about this condition. PATIENTS/MATERIAL AND METHODS: The current study includes 27 eyes of 25 patients aged up to 18 years that were operated on between 2000 and 2012. They presented 42.4 % of all RRD of that age group. We analyzed the following parameters: demographic data, retinal detachment characteristics, surgical techniques and outcomes. RESULTS: Mean age was 15,3 years and 77 % were boys. Retinal detachment occurred between 3 days and 11 years after trauma (median: 3,5 months). Two thirds of RRDs were classified as acute, the remainder showed symptoms of chronicity, e.g. pigment demarcation and subretinal strands or PVR. The macula was detached in 81,5 %. Retinal dialysis was the most common type of break (44,8), followed by giant retinal tears (18,5 %). In 3 out of 5 eyes with severe PVR due to self-aggressive behavior a causative retinal defect was not identified. Episcleral buckling surgery was the preferred method in any case that deemed manageable with a segmental sponge or encircling band (14 eyes). Primary vitrectomy was performed in more complex retinal detachments (13 eyes), and most of them had silicone oil tamponade. Primary reattachment was achieved in 83 % in the buckling group and 80 % in the vitrectomy group (3 eyes with self-harm excluded). Finally, all eyes had attached retinas. Postoperatively, visual acuity improved or remained stable in successfully treated eyes. Late complications in the vitrectomy group were cataract development in half of the phakic eyes. CONCLUSIONS: Retinal dialysis and giant retinal tears are the most frequent retinal lesions in posttraumatic RRD. Delayed diagnosis is a common problem, as most of the cases preset with macula-off detachments and clinical signs of chronic RRD. A conventional approach to traumatic RRD using scleral buckling techniques is recommended whenever possible. Differently from adults, strong vitreoretinal adhesions are present and the vitreous is rarely detached which makes a complete vitrectomy challenging. Furthermore there is a significant risk of postoperative cataract despite of the young age. However, cases with giant retinal tear and complex detachments due to PVR require vitrectomy maneuvers, usually with the use of silicone oil. A special subgroup presents PVR-detachments due to chronic auto-aggressive behavior of disabled young patients. Despite of extreme vitreoretinal maneuvers used, those eyes might be inoperable or late failures due to chronic aggressive PVR. On the whole, delayed diagnosis and advanced RRD limit final vision. However, after successful surgery, approximately half of the eyes improve, many retain vision. As preserving vision in young patients is of great impact for their whole lifespan, any attempt should be made to achieve a stable retinal situation.

[Subretinal hemorrhage. Natural course and staging]. / Subretinale Blutungen. Spontanverlauf und Stadieneinteilung.

Subretinal hemorrhages are a complication of various diseases which arise from the choroidal or retinal circulation. Most commonly the underlying pathology is a choroidal neovascular membrane (CNV) especially in patients with age-related macular degeneration (AMD). Less common ocular diseases are those with non-AMD-related CNV and retinal arterial macroaneurysms (RAM). Case studies have demonstrated a poor prognosis, however, a significant portion have favorable outcomes. Therefore, therapeutic decision-making is difficult. As a major difficulty in comparing different treatment modalities for submacular hemorrhages is the lack of a standardized definition of the extent of the hemorrhage. A classification for AMD-related subretinal hemorrhages including size, thickness and intraretinal location is suggested.

Cell differentiation and matrix organization in engineered teeth.

Embryonic dental cells were used to check a series of criteria to be achieved for tooth engineering. Implantation of cultured cell-cell re-associations led to crown morphogenesis, epithelial histogenesis, organ vascularization, and root and periodontium development. The present work aimed to investigate the organization of predentin/dentin, enamel, and cementum which formed and mineralized after implantation. These implants were processed for histology, transmission electron microscopy, x-ray microanalysis, and electron diffraction. After two weeks of implantation, the re-associations showed gradients of differentiating odontoblasts. There were ciliated, polarized, and extended cell processes in predentin/dentin. Ameloblasts became functional. Enamel crystals showed a typical oriented arrangement in the inner and outer enamel. In the developing root, odontoblasts differentiated, cementogenesis occurred, and periodontal ligament fibroblasts interacted with the root surface and newly formed bone. The implantation of cultured dental cell re-associations allows for reproduction of complete functional differentiation at the cell, matrix, and mineral levels.

[Visual development of postoperative persistent macular holes with and without surgical revision]. / Visusverlauf bei postoperativ persistierendem Makulaforamen mit und ohne Revisionseingriff.

BACKGROUND: Postoperative persistent macular holes after vitrectomy are a rare, but typical phenomenon. Without further surgical intervention the visual acuity remains unchanged. There are no generally accepted treatment recommendations for these cases. We report on 23 cases with postoperative persistent macular holes with and without further surgical treatment and analyzed the clinical outcome. METHODS: A retrospective case control study was performed and visual acuity and anatomic status of the macular holes were analysed in 23 cases with a persistent macular hole after previous vitrectomy. Seven patients refused further surgical treatment (group 1) and were used as a control group. Three patients received a second intravitreal gas tamponade without further surgical manipulation (group 2). A vitrectomy revision with endotamponade was performed in 13 eyes (group 3). Additional autologous blood on the macular hole was used in 4 cases and adjuvant ICG-assisted peeling of the inner limiting membrane around the macular hole was performed in another 9 cases. RESULTS: The eyes of group 1 showed a statistically not significant (p = 0.56) change of the median LogMAR visual acuity from 1.3 (range 0.7 - 1.4) to 1.2 (range 0.3 - 2.0) over a median follow-up of 11.8 months. No eye in group 2 developed a closure of the macular hole. After a median follow-up of 3.6 months the LogMAR visual acuity dropped statistically not significantly from 0.7 (range 0.7 - 1.9 to 1.0 (range 0.8 - 1.0; p = 0.5). 61 % of eyes showed a closure of the macular hole after a second vitrectomy (group 3). Eight out of 16 retreated eyes had finally a persistent macular hole. In these cases median LogMAR visual acuity decreased insignificantly from 1.0 (range 0.7 - 1.4) to 1.1 (range 0.7 - 1.4; p = 0.27) during a median follow-up of 13.7 months. In 8 eyes with a finally closed macular hole median LogMAR visual acuity increased statistically significantly from 0.8 (rage 0.4 - 1.3) to 0.35 (range 0.04 - 0.9; p = 0.016) after a median follow-up of 8.1 months. CONCLUSION: Surgical revision of postoperative persistent macular holes using vitrectomy and endotamponade showed a success rate of 61 %. Eyes that had unsuccessful subsequent surgery had a slight decay of the visual acuity during the follow-up that was similar to that of eyes without further surgical treatment. In contrast, the final closure of the macular hole after a second surgery was associated with a significantly increased visual acuity.

Vascularization of engineered teeth.

The implantation of cultured dental cell-cell re-associations allows for the reproduction of fully formed teeth, crown morphogenesis, epithelial histogenesis, mineralized dentin and enamel deposition, and root-periodontium development. Since vascularization is critical for organogenesis and tissue engineering, this work aimed to study: (a) blood vessel formation during tooth development, (b) the fate of blood vessels in cultured teeth and re-associations, and (c) vascularization after in vivo implantation. Ex vivo, blood vessels developed in the dental mesenchyme from the cap to bell stages and in the enamel organ, shortly before ameloblast differentiation. In cultured teeth and re-associations, blood-vessel-like structures remained in the peridental mesenchyme, but never developed into dental tissues. After implantation, both teeth and re-associations became revascularized, although later in the case of the re-associations. In implanted re-associations, newly formed blood vessels originated from the host, allowing for their survival, and affording conditions organ growth, mineralization, and enamel secretion.

[Late recurrences more than 1 year after primary successful surgery for rhegmatogenous retinal detachment]. / Reamotio mehr als 1 Jahr nach primär erfolgreicher Ablatiochirurgie: Ursachen und Häufigkeit.

BACKGROUND: Recurrent retinal detachment following initial successful surgery usually occurs in the early postoperative course. Redetachment after 1 or more years of complete retinal reattachment is a rare event. The present study investigates the frequency and causes of late recurrences. PATIENTS/MATERIAL AND METHODS: A consecutive series of 2,232 eyes that presented with rhegmatogenous retinal detachment (RD) were treated between January 1994 and December 2006. Among them were 30 cases (30 eyes) presenting with late recurrent RD (1.34 %). We compared the clinical characteristics of initial and late recurrent RD. RESULTS: Over the 13-year period, 54.5 % of rhegmatogenous RD cases were treated with scleral buckling, 42.5 % using vitrectomy techniques and 2.55 % with pneumatic retinopexy. Late recurrent RD occurred 1.1 - 10.4 years (average 3.8, SD 2.56) after initially successful surgery. Previous surgery included scleral buckling in 24 eyes (80 %), vitrectomy in 5 eyes (16.7 %) and pneumatic retinopexy in another eye (3.3 %). At the time of initial treatment, primary reattachment rate was 93.3 % and final 100 %. At the time of late redetachment, the anatomic situation appeared more complex. Accordingly, most eyes were treated by vitrectomy (73.3 %), and only 23.3 % using buckling techniques. Furthermore, the numbers of reoperations to achieve reattachment increased from 6.6 % to 23.3 %. Major causes for late failures were vitreous base traction leading to new or reopened breaks and PVR. Three eyes showed these complications immediately after complicated anterior segment surgery. Comparing visual outcomes after initial (preop logMAR 0.57 +/- 0.7 and postop 0.38 +/- 0.43) and late (preop logMAR 0.87 +/- 0.71 and postop 0.66 +/- 0.5) RD, functional prognosis is worse when redetachment occurs. Nonetheless, in 50 % of eyes useful vision (>or= 20 / 50) was retained by repeat surgery. CONCLUSIONS: Recurrent retinal detachment that presents after more than 1 year of complete reattachment occurs in 1.34 % of cases according to the present study. We found a higher rate after scleral buckling compared to vitrectomy. The most important reasons for late failures are vitreous base traction and periretinal proliferations that clinically appear as new or reopened tears or as PVR. Recurrences show a more difficult retinal situation and require more extensive surgical interventions. Based on the anatomic and functional success rates, repeat surgical procedures are worth considering.

Treatment of central retinal vein occlusion by radial optic neurotomy in 107 cases.

BACKGROUND: To evaluate the potential role of radial optic neurotomy (RON), a new surgical technique has been recently proposed for treating central retinal vein occlusion (CRVO). It is hypothesized that CRVO constitutes a neurovascular compartment syndrome at the site of the lamina cribrosa, which can be alleviated by performing a radial incision at the nasal part of the optic nerve head, relaxing the cribriform plate and the adjacent sclera. METHODS: One hundred and seven patients were treated with RON for CRVO at five collaborating ophthalmologic centers. All patients were evaluated by a standardized protocol. For analysis of the angiographic and fundus findings, reference images were used. Intraoperative and postoperative complications were reviewed. RESULTS: On 55 right and 52 left eyes of 107 patients (55.6% male, 44.4% female) with a median age of 68 years (range 21-91 years), RON was performed. The median follow-up time was 6 months (range 1-24 months). The median preoperative visual acuity (VA) was 0.05 (logMAR 1.3), increasing to a median postoperative VA of 0.08 (logMAR 1.1). Patients with an interval of more than 90 days between RON and onset of CRVO showed no significant change in VA at the 6-month follow-up. Severe peripapillary swelling of the optic nerve head prior to RON resulted in an average increase of 4.2 lines in VA at the 6-month follow-up. Angiographic findings of shunt vessels were seen in 18/30 cases after 12 months and were accompanied by an average improvement of VA of six lines. Visual field tests showed various defects in 86.8% of all cases. In one patient an iatrogenic injury of the central retinal artery occurred (0.9%). CONCLUSION: Despite the potential risk of visual field defects, RON seems to be a quite safe procedure. The majority of patients showed rapid normalization of the morphologic fundus findings, with an improvement in VA uncommon for the natural history of CRVO. No significant change in VA was seen in patients with an interval of more than 90 days between the onset of CRVO and RON. A prospective study is warranted for further investigation.

Verteporfin photodynamic therapy induced apoptosis in choroidal neovascular membranes.

AIM: To evaluate the impact of verteporfin photodynamic therapy (PDT) on the induction of apoptosis in choroidal neovascular membranes (CNV) secondary to age related macular degeneration. METHODS: Retrospective review of 22 surgically excised CNV. 12 of these patients had been treated with PDT 3-146 days previously. Apoptotic cells were detected with the TUNEL technique and compared to the expression of CD34 (endothelial cells, EC), CD105 (activated endothelial cells), Ki-67 (proliferation marker), and cytokeratin18 (retinal pigment epithelial cells, RPE). RESULTS: CNV excised 3 days after PDT were characterised both by collapsed and patent vessels. The EC displayed a statistical significant positive TUNEL reaction when compared to the remaining treated CNV (p < 0.001) and untreated CNV (P = 0.002). The proliferative activity was reduced. CNV excised 1-5 months after PDT displayed a patent vascularisation and high proliferative activity. All membranes either treated or untreated disclosed only sporadic TUNEL positive cells within the stroma and the RPE. CONCLUSIONS: Verteporfin PDT leads to selective and effective damage of EC within CNV. Both patent and occluded vessels were lined by apoptotic EC. This finding and the increased expression of proliferation marker at later time points suggest that revascularisation after PDT is caused by angiogenesis rather than recanalisation.

Expression patterns of BMPRs in the developing mouse molar.

During development, Bone Morphogenetic Proteins (BMPs) can induce apoptosis, cell growth or differentiation. These different effects are mediated by dimers of two types of BMP-receptors (BMPRs). To identify the responding cells during tooth development and search for possible tissue-or stage-specificities in the receptors involved, the distribution patterns of BMPR-IA, -IB and -II were investigated in the mouse molar, from bud to bell stage. At the bud stage, BMP-2 was suggested to be involved in the formation of an epithelial signaling center, the primary enamel knot (PEK), while BMP-4 would mediate the condensation of the mesenchyme. Immunostaining showed the presence of BMPR-IA and -II in the epithelium instead of BMPR-IB and -II in the mesenchyme. At the cap stage, BMPR-IB was detected in the epithelium but not BMPR-II, suggesting the existence of another type II receptor to form a functional dimer. At the late cap stage in the epithelium, BMP-4, BMPR-IA and -II were restricted to the internal part of the PEK and the stalk: two apoptotic areas. The three proteins were detected in the mesenchyme, showing a strong staining where cusps were about to form. At the late bell stage, BMP-2 or -4 may induce cell differentiation. BMPR-IB and -II were detected in odontoblasts instead of BMPR-IA and -II in ameloblasts. These results provide the first evidence of multiple type I and type II BMP-receptors, expressed in the dental epithelium and mesenchyme at different stages of development, to signal different cellular activities in a time- and tissue-specific way.

Immunolocalization of BMP-2/-4, FGF-4, and WNT10b in the developing mouse first lower molar.

Intercellular signaling controls all steps of odontogenesis. The purpose of this work was to immunolocalize in the developing mouse molar four molecules that play major roles during odontogenesis: BMP-2, -4, FGF-4, and WNT10b. BMP-2 and BMP-4 were detected in the epithelium and mesenchyme at the bud stage. Staining for BMP-2 markedly increased at the cap stage. The relative amount of BMP-4 strongly increased from E14 to E15. At E15, BMP-4 was detected in the internal part of the enamel knot where apoptosis was intense. In contrast to TGFbeta1, BMP-2 and -4 did not show accumulation at the epithelial-mesenchymal junction where the odontoblast started differentiation. When odontoblasts became functional, BMP-2 and BMP-4 were detected at the apical and basal poles of preameloblasts. BMP-2, which induces ameloblast differentiation in vitro, may also be involved physiologically. The decrease in FGF-4 from E14 to E15 supports a possible role for the growth factor in the control of mesenchymal cell proliferation. The relative amount of FGF-4 was maximal at E17. The subsequent decrease at E19 showed correlation with the withdrawal of odontoblasts and ameloblasts from the cell cycle. WNT10b might also stimulate cell proliferation. At E14-15, WNT10b was present in the mesenchyme and epithelium except for the enamel knot, where the mitotic activity was very low. At E19 there was a decreasing gradient of staining from the cervical loop where cells divide to the tip of the cusp in the inner dental epithelium where cells become postmitotic. The target cells for FGF-4 and WNT10b appeared different.

Hipertrofia compensadora após o autotransplante renal em cães associado à nefrectomia contralateral

O artigo não apresenta resumo.