Subcurative radiation significantly increases cell proliferation, invasion, and migration of primary glioblastoma multiforme in vivo / 癌症

Tumor cell proliferation, infiltration, migration, and neovascularization are known causes of treatment resistance in glioblastoma multiforme (GBM). The purpose of this study was to determine the effect of radiation on the growth characteristics of primary human GBM developed in a nude rat. Primary GBM cells grown from explanted GBM tissues were implanted orthotopically in nude rats. Tumor growth was confirmed by magnetic resonance imaging on day 77 (baseline) after implantation. The rats underwent irradiation to a dose of 50 Gy delivered subcuratively on day 84 postimplantation (n = 8), or underwent no radiation (n = 8). Brain tissues were obtained on day 112 (nonirradiated) or day 133 (irradiated). Immunohistochemistry was performed to determine tumor cell proliferation (Ki-67) and to assess the expression of infiltration marker (matrix metalloproteinase-2, MMP-2) and cell migration marker (CD44). Tumor neovascularization was assessed by microvessel density using von-Willebrand factor (vWF) staining. Magnetic resonance imaging showed well-developed, infiltrative tumors in 11 weeks postimplantation. The proportion of Ki-67-positive cells in tumors undergoing radiation was (71 +/- 15)% compared with (25 +/- 12)% in the nonirradiated group (P = 0.02). The number of MMP-2-positive areas and proportion of CD44-positive cells were also high in tumors receiving radiation, indicating great invasion and infiltration. Microvessel density analysis did not show a significant difference between nonirradiated and irradiated tumors. Taken together, we found that subcurative radiation significantly increased proliferation, invasion, and migration of primary GBM. Our study provides insights into possible mechanisms of treatment resistance following radiation therapy for GBM.

The Effect of Poloxamer 407-Based Hydrogel on the Osteoinductivity of Demineralized Bone Matrix

BACKGROUND: Demineralized bone matrix (DBM) is used for bone healing due to its osteoinductivity, but it requires a carrier for clinical application. Here, we report the effects on the osteoinductivity of DBM by use of a poloxamer 407-based hydrogel as the carrier, compared to sterile water. METHODS: DBM-W and DBM-H represent 27 wt% of DBM with sterile water and DBM with a poloxamer 407-based hydrogel, respectively. Both of the compositions were applied to human mesenchymal stem cell (MSC) cultures, and monitored for alkaline phosphatase (ALP) staining and ALP activity. Six 10-week-old athymic nude rats were used for abdominal muscle grafting with either DBM-W or DBM-H, and were tested by plane radiography, microfocus X-ray computed tomography (CT), and decalcified histology to evaluate ectopic bone formation. RESULTS: The DBM-W group showed stronger ALP staining at 7, 14, and 21 days of treatment, and significantly higher ALP activity at 7 and 14 days of treatment, compared to the DBM-H group. Plane radiography could not confirm the radio-opaque lesions in the rat ectopic bone formulation model. However, ectopic bone formation was observed in both groups by micro-CT. Compared to the DBM-H group, the DBM-W group showed higher bone volume, percent bone volume and trabecular number, and the difference in percent bone volume was statistically significant. Decalcified histology found bony tissue with lamellation in both groups. CONCLUSIONS: Our results suggest that poloxamer 407-based hydrogel has efficacy as a DBM carrier since it shows ectopic bone formation, but its effects on the quality and quantity of osteoblastic differentiation in rat abdominal ectopic bone and MSC are considered negative.

Translational Research: Palatal-derived Ecto-mesenchymal Stem Cells from Human Palate: A New Hope for Alveolar Bone and Cranio-Facial Bone Reconstruction

The management of facial defects has rapidly changed in the last decade. Functional and esthetic requirements have steadily increased along with the refinements of surgery. In the case of advanced atrophy or jaw defects, extensive horizontal and vertical bone augmentation is often unavoidable to enable patients to be fitted with implants. Loss of vertical alveolar bone height is the most common cause for a non primary stability of dental implants in adults. At present, there is no ideal therapeutic approach to cure loss of vertical alveolar bone height and achieve optimal pre-implantological bone regeneration before dental implant placement. Recently, it has been found that specific populations of stem cells and/or progenitor cells could be isolated from different dental resources, namely the dental follicle, the dental pulp and the periodontal ligament. Our research group has cultured palatal-derived stem cells (paldSCs) as dentospheres and further differentiated into various cells of the neuronal and osteogenic lineage, thereby demonstrating their stem cell state. In this publication will be shown whether paldSCs could be differentiated into the osteogenic lineage and, if so, whether these cells are able to regenerate alveolar bone tissue in vivo in an athymic rat model. Furthermore, using these data we have started a proof of principle clinical- and histological controlled study using stem cell-rich palatal tissues for improving the vertical alveolar bone augmentation in critical size defects. The initial results of the study demonstrate the feasibility of using stem cell-mediated tissue engineering to treat alveolar bone defects in humans.

Morphological study of bone cranial in athymic mice / Estudio morfológico de hueso craneal en ratones atímicos

The aim of our research was to create an osteogenic unit in the skulls of athymic mice; however, the first challenge we faced was to find sufficient and adequate data that would allow us to determine the morphological, immunohistochemical and microtopographical characteristics that could be used as normality standards in athymic mice skulls and, hence, a reference in the event of achieving the formation of de novo bone using the osteogenic unit we proposed. Knowing the normal bone morphology in the skull of athymic mice was a necessary precondition to develop subsequently an osteogenic unit possessing the Osteogenesis, Osteoinduction and Osteoconductivity that could be compared versus those in the normal bone during its formations and remodeling processes. Therefore, we conducted a pilot study to determine bone morphological characteristics in the skull of athymic mice by means of specific histological staining: hematoxylin-eosin and Von Kossa, for osteoid tissue and mineralized bone, and Masson Tri-chrome for ossified areas. We also use immunohistochemistry to detect bone formation markers: alkaline phosphatase resulting from osteoblastic activity stimulation, type 1 collagen a bonematrix structural protein; Osteopontine, a protein specifically synthesized by osteoblasts that favors cell proliferation and remodeling in bone defects; Osteocalcine, a peptide hormone produced by osteoblasts during bone formation; and, Runx 2, a transcription factor expressed by stem cells which stimulates bone differentiation. Likewise, we used electron microscopy on the newly formed tissue to determine the presence of organic deposits, such as calcium, phosphate and magnesium in bone tissue.

Propusimos la realización de una unidad osteogénica a desarrollar en cráneo de ratones atímicos, Sin embargo, nos enfrentamos al reto de encontrar datos que nos determinaran cuales eran las características morfológicas, inmunohistoquímicas y micro-topográficas del cráneo de estos ratones atímicos, que nos sirvieran como referencia de normalidad y tener un punto de comparación, en caso de que pudiéramos lograr la formación de hueso de novo, a partir de la unidad osteogénica que propusimos. El objetivo, de conocer la morfología del hueso normal de cráneo de ratones atímicos, fue desarrollar posteriormente una unidad osteogénica que reuniera las características de Osteogénesis, Osteoinducción y Osteoconducción, y, compararlas contra las que tiene dicho hueso normal durante su proceso de formación y remodelación. Así, realizamos un estudio piloto donde establecimos características morfológicas de hueso del cráneo de ratones atímicos, a través de tinciones histológicas específicas, con hematoxilina-eosina y von Kossa para buscar tejido osteoide y hueso mineralizado y Tricrómico de Massón para observar zonas osificadas. Además, analizamos el tejido óseo a través de inmunohistoquímica, con la finalidad de buscar marcadores de formación ósea como fosfatasa alcalina que es resultado del estímulo de la actividad osteoblástica; colágena 1, la cual es una proteína estructural de la matriz ósea; osteopontina, proteína sintetizada específicamente por osteoblastos que favorece la proliferación celular y la remodelación en defectos óseos; osteocalcina hormona peptídica producida por los osteoblastos durante la formación ósea y Runx 2 Factor de transcripción expresado por las células progenitoras que estimula la diferenciación ósea. Además, sometimos el tejido óseo a microscopía electrónica para determinar la presencia de depósitos de compuestos como calcio, fósforo y magnesio.

Study on in vitro/in vivo correlation of extracts from Ligusticum chuanxiong after transdermal administration / 中国中药杂志

<p><b>OBJECTIVE</b>To study the transdermal permeation and in vivo pharmacokinetics of effective constituent ferulic acid from Ligusticum chuanxiong, in order to establish the in vitro/in vivo correlation in transdermal permeation.</p><p><b>METHOD</b>Franz diffusion cell was adopted in the in vitro transdermal permeation, with CD-1 nude rat abdominal skin as the permeation medium. Linear probes were implanted in CD-1 nude rats. With PBS as perfusate, microdialysis was employed to study the pharmacokinetics. Ferulic acid concentrations in the receptor solution and dialysate were assessed by high performance liquid chromatography (HPLC). The study on correlation between in vitro and in vivo data was conducted by deconvolution methods.</p><p><b>RESULT</b>The transdermal permeation rate of ferulic acid from Ligusticum chuanxiong was (0.094 4 +/- 0.049 4) microg x cm2 x min, with Cmax of ferulic acid being 808.91 microg x L(-1), and Tmax being 183 min after dermal administration. The in vitro/in vivo correlation was 93.61.</p><p><b>CONCLUSION</b>Ferulic acid in extracts from L. chuanxiong can quickly penetrate skins. By using the in vitro/in vivo correlation in transdermal permeation, simple in vitro transdermal permeation method can be adopted to study the changes in its pharmacokinetics.</p>

Establishment of Efficacy and Safety Assessment of Human Adipose Tissue-Derived Mesenchymal Stem Cells (hATMSCs) in a Nude Rat Femoral Segmental Defect Model

Human adipose tissue-derived mesenchymal stem cell (hATMSC) have emerged as a potentially powerful tool for bone repair, but an appropriate evaluation system has not been established. The purpose of this study was to establish a preclinical assessment system to evaluate the efficacy and safety of cell therapies in a nude rat bone defect model. Segmental defects (5 mm) were created in the femoral diaphyses and transplanted with cell media (control), hydroxyapatite/tricalcium phosphate scaffolds (HA/TCP, Group I), hATMSCs (Group II), or three cell-loading density of hATMSC-loaded HA/TCP (Group III-V). Healing response was evaluated by serial radiography, micro-computed tomography and histology at 16 weeks. To address safety-concerns, we conducted a GLP-compliant toxicity study. Scanning electron microscopy studies showed that hATMSCs filled the pores/surfaces of scaffolds in a cell-loading density-dependent manner. We detected significant increases in bone formation in the hATMSC-loaded HA/TCP groups compared with other groups. The amount of new bone formation increased with increases in loaded cell number. In a toxicity study, no significant hATMSC-related changes were found in body weights, clinical signs, hematological/biochemical values, organ weights, or histopathological findings. In conclusion, hATMSCs loaded on HA/TCP enhance the repair of bone defects and was found to be safe under our preclinical efficacy/safety hybrid assessment system.

Xenograft transplantation of human malignant astrocytoma cells into immunodeficient rats: an experimental model of glioblastoma

INTRODUCTION: Astrocytic gliomas are the most common intracranial central nervous system neoplasias, accounting for about 60 percent of all primary central nervous system tumors. Despite advances in the treatment of gliomas, no effective therapeutic approach is yet available; hence, the search for a more realistic model to generate more effective therapies is essential. OBJECTIVE: To develop an experimental malignant astrocytoma model with the characteristics of the human tumor. METHOD: Primary cells from subcutaneous xenograft tumors produced with malignant astrocytoma U87MG cells were inoculated intracerebrally by stereotaxis into immunosuppressed (athymic) Rowett rats. RESULTS: All four injected animals developed non-infiltrative tumors, although other glioblastoma characteristics, such as necrosis, pseudopalisading cells and intense mitotic activity, were observed. CONCLUSION: A malignant astrocytoma intracerebral xenograft model with poorly invasive behavior was achieved in athymic Rowett rats. Tumor invasiveness in an experimental animal model may depend on a combination of several factors, including the cell line used to induce tumor formation, the rat strains and the status of the animal's immune system.

Repair of calvarial defects with human umbilical cord blood derived mesenchymal stem cells and demineralized bone matrix in athymic rats / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the feasibility of using human umbilical cord blood derived mesenchymal stem cells (UCB-MSCs) and demineralized bone matrix (DBM) scaffolds to repair critical-sized calvarial defects in athymic rats.</p><p><b>METHODS</b>Human UCB-MSCs were isolated, expanded and osteogenically induced in vitro. Osteogenic differentiation of UCB-MSCs was evaluated by Alizarin Red staining and measurement of calcium content respectively, and then the cells were seeded onto DBM scaffolds. Bilateral full-thickness defects (5 mm in diameter) of parietal bone were created in an athymic rat model. The defects were either repaired with UCB-MSC/DBM constructs (experimental group) or with DBM scaffolds alone (control group). Animals were harvested at 6 and 12 weeks post-implantation respectively, and defect repair was evaluated with gross observation, micro-CT measurement and histological analysis.</p><p><b>RESULTS</b>Micro-CT showed that new bone was formed in the experimental group at 6 weeks post-implantation, while no sign of new bone formation was observed in the control group. At 12 weeks post-transplantation, scaffolds had been degraded almost completely in both sides. It was shown that an average of (78.19 +/- 6.45)% of each defect volume had been repaired in experimental side; while in the control side, only limited bone formed at the periphery of the defect. Histological examination revealed that the defect was repaired by trabecular bone tissue in experimental side at 12 weeks, while only fibrous connection was observed in the control group.</p><p><b>CONCLUSIONS</b>Tissue-engineered bone composed of osteogenically-induced human UCB-MSCs on DBM scaffolds could successfully repair the critical-sized calvarial defects in athymic rat models.</p>

Angiogenic factor-enriched platelet-rich plasma enhances in vivo bone formation around alloplastic graft material

PURPOSE: Although most researchers agree that platelet-rich plasma (PRP) is a good source of autogenous growth factors, its effect on bone regeneration is still controversial. The purpose of this study was to evaluate whether increasing angiogenic factors in the human PRP to enhance new bone formation through rapid angiogenesis. MATERIAL AND METHODS: In vitro, the human platelets were activated with application of shear stress, 20 microgram/ml collagen, 2 mM CaCl2 and 10U thrombin/1 x 109 platelets. Level of vascular endothelial growth factor (VEGF) and platelet microparticle (PMP) in the activated platelets were checked. In the animal study, human angiogenic factors-enriched PRP was tested in 28 athymic rat's cranial critical bone defects with beta-TCP. Angiogenesis and osteogenesis were evaluated by laser Doppler perfusion imaging, histology, dual energy X-ray densinometry, and micro-computed tomography. RESULTS: In vitro, this human angiogenic factors-enriched PRP resulted in better cellular proliferation and osteogenic differentiation. In vivo, increasing angiogenic potential of the PRP showed significantly higher blood perfusion around the defect and enhanced new bone formation around acellular bone graft material. CONCLUSION: Angiogenic factor-enriched PRP leads to faster and more extensive new bone formation in the critical size bone defect. The results implicate that rapid angiogenesis in the initial healing period by PRP could be supposed as a way to overcome short term effect of the rapid angiogenesis.

Experimental nodel of C6 brain tumors in athymic rats / Modelo experimental de tumor cerebral C6 em ratos atímicos

Malignant brain tumor experimental models tend to employ cells that are immunologically compatible with the receptor animal. In this study, we have proposed an experimental model of encephalic tumor development by injecting C6 cells into athymic Rowett rats, aiming at reaching a model which more closely resembles to the human glioma tumor. In our model, we observed micro-infiltration of tumor cell clusters in the vicinity of the main tumor mass, and of more distal isolated tumor cells immersed in normal encephalic parenchyma. This degree of infiltration is superior to that usually observed in other C6 models.

Modelos experimentais de tumores cerebrais malignos geralmente utilizam células imunologicamente compatíveis com o animal receptor. Neste estudo apresentamos um modelo experimental baseado na inoculação de células C6 em ratos atímicos Rowett, visando obter um tumor que se assemelhe mais àqueles observados nos seres humanos. Neste modelo observamos microinfiltração de ilhotas de células na periferia da massa tumoral principal e nas áreas mais distantes, células tumorais isoladas no tecido cerebral normal. Este grau de infiltração é superior àquele observado em outros modelos utilizando as células C6.

Experimental model of cultured skin graft

Um dos modelos animais mais utilizados de auto-enxertia de queratinócitos cultivados é baseado em xeno-enxerto de queratinócitos humanos em rato atímico, um receptor imunologicamente neutro que atua como carreador biológico. Muitos fatos podem ser estudados nesse modelo que acontecem após o transplante sem os aspectos éticos do estudo clínico. A proposição do modelo experimental esta relacionada a sequência do transplante de pele parcial ou total como auto-enxerto ou xeno-enxerto, cultivado ou não, no dorso do rato atímico. O modelo apresenta a possibilidade do estudo in vivo do animal atímico, quando o estudo in vivo em anima nobili não é considerado ético. Isso permite a avaliação do xeno-enxerto de células humanas normais ou modificadas geneticamente modificadas cultivadas e a associação de células cultivadas e substitutes dérmicos, de enxertos compostos e de auto-enxerto.

Modulatory Effect of TGF-beta 2 to Proliferative Kinetics of Fibroblast in Keloid and Hypertrophic Scar

Keloid and hypertrophic scar are dermal fibroproliferative disorders characterized by an overabundant deposition of collagen. Recently these dermal proliferative disorders have been linked clinically to the cytokine transforming growth factor beta(TGF-beta), and in vitro tests have shown it to be responsible for the activation of fibroblasts and their production and deposition of collagen. By using an established in vivo animal model of proliferative scarring, these scars were examined. Proliferative scar specimens were implanted into athymic, asplenic nude rats and isolated in sandwich island flap based on the superficial inferior epigastric pedicle. After establishment of the transferred flap, the scars were injected with varying doses of TGF-beta 2 or vehicle for 5 consecutive days and then again on days 10, 15, and 20. The specimens were measured weekly during the period of dosing, and a biopsy was acquired on days 30 and 60. Fibroblasts from the explanted biopsies and the original scars were grown in cell culture, and cell proliferation studies were performed and the results compared. There was a dose response to TGF-beta 2, with 200ng showing the greatest effect. From the original scar specimens, keloid scars demonstrated the greatest cell proliferation kinetics-significantly faster than hypertrophic scars. After treatment with TGF-beta 2, keloids showed an increase in their cell proliferation kinetics compared with vehicle alone. This was not demonstrated with the hypertrophic scars. Elevated levels of TGF-beta 2 are a major contributing factor to the process of proliferative scars, but because hypertrophic scars do not result in an equally increased response to this cytokine, a truly causative role for this cytokine cannot be promulgated. Rather, it is rather combination of the proliferative scar fibroblasts' abnormal response to TGF-beta 2 stimulation and elevated levels of this cytokine that controls more accurately the process of keloid formation.

Expression of enhanced green fluorescent protein in transduced variant HT-29c cells in vitro and in vivo / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the gene transfer and expression of enhanced green fluorescent protein (EGFP) in retrovirally transducted variant HT-29c cells in vitro and in vivo.</p><p><b>METHODS</b>The retroviral vector prkat EGFP/neo was constructed and was transfected into the 293T cell using a standard calcium phosphate precipitation method. HT-29c cells (in vivo selected HT-29 cells) were transduced by a retroviral vector encoding the EGFP gene. The fluorescence intensity of colorectal carcinoma HT-29c cells after transfected with the EGFP gene bearing retrovirus was visualized using fluorescence microscope and fluorescence activated cell sorter analysis. Multiple biological behaviors of transduced cells such as the proliferating potential and the expression of various antigens were comparatively analyzed between untransfected and transfected in vitro. EGFP expression of the fresh tumor tissue was assessed in vivo.</p><p><b>RESULTS</b>After being transduced, HT-29c cells with the EGFP gene displayed a stable and long-term EGFP expression under the nonselective conditions in vitro. After culturing cells successively to passage 50 in vitro, EGFP expression level was still high. Their biological behaviors, such as expression of tumor antigens, proliferation rate and aggregation capability were not different compared to untransfected parental cells in vitro. In subcutaneous tumors, EGFP was stable and highly expressed.</p><p><b>CONCLUSIONS</b>An EGFP expressing retroviral vector was used to transduce HT-29c cells. The transduced cells show a stable and long-term EGFP expression in vitro and in vivo. These cells are a valuable tool for in vivo analysis of metastatic spread.</p>

in vitro and in vivo Photodynamic Activity Study of U-87 Human Glioma Cell with Photofrin

OBJECTIVE: The objective of this study was to determine the photodynamic therapeutic response of U-87 human glioma cell in vitro as well as in the nude rat xenograft model using photofrin as photosensitizer. MATERIAL AND METHOD: U-87 cells were cultured on 96-well culture plates, photofrin(Quadralogic Technologies Inc., Vancouver, Canada) was added into the cell culture medium at concentration of 1ng/ml, 2.5ng/ml, 5ng/ml, 10ng/ml and 20ng/ml. 24 hour after drug treatment, cells were treated with optical(632nm) irradiation of 100mJ/cm2, 200mJ/cm2 and 400mJ/cm2. Photofrin(12.5mg/kg, i.p.) was administered to 28 nude rats containing intracerebral U-87 human glioma as well as 26 normal nude rats. 48 hours after administration, animals were treated with optical irradiation(632nm) of 35J/cm2, 140J/cm2 and 280J/cm2 to exposed tumor and normal brain. The photofrin concen-tration was measured in tumor and normal brain in a separate population of animals. RESULTS: By MTT assay, there was 100% cytotoxicity at any dose of photofrin with optical irradiation of 200mJ/cm2 and 400mJ/cm2. But at the optical irradiation of 100mJ/cm2 cells were killed in dose dependent manner 28.5%, 49.1%, 54.4%, 78.2%, and 84.6% at concentration of 1ng/ml, 2.5ng/ml, 5ng/ml, 10ng/ml and 20ng/ml, respectively. Dose dependent PDT lesions in both tumor and normal brain were observed. In the tumor lesion, only superficial tissue damage was found with optical irradiation of 35J/cm2. However, in the optical irradiation group of 140J/cm2 and 280J/cm2 the volume of lesions was measured of 7.2mm3 and 14.0mm3 for treatment at 140J/cm2 and 280J/cm2, respectively. The U-87 bearing rats showed a photofrin concentration in tumor tissue of 6.53+/-2.16ng/g, 23 times higher than that found in the contralateral hemisphere of 0.28+/-0.15ng/g. CONCLUSION: Our data indicate that the U-87 human glioma in vitro and in the xenografted rats is responsive to PDT. At these doses, a reproducible injury can be delivered to human glioma in this model. Strategies to spare the normal brain collateral damage are being studied.

A New Animal Model of Proliferative Scarring

Proliferative scarring in the form of keloids and hypertrophic scars continues to be a clinical problem for some patients. The lack of an animal model for such scarring has been an obstacle to studying the biology and effective therapy of these entities. Consequently we created an accurate reproductive animal model to systematically study them. Human proliferative scars were explanted into flaps based on isolated vascular pedicles in congenitally rats. We compared the procollagen type III peptide levels of proliferative scar tissue before and after explanting. The procollagen type III peptide levels of explanted proliferative scar tissue remained increased as before explanting. Histological analysis of the explanted proliferative scar tissue revealed that all explants retained their original histotypic character even after 1 year. We could also retain the volume of implanted proliferative scar for 1 year and studied in vitro cellular proliferation. Fibroblast cultures from explanted scars demonstrated less aggressive growth characteristic than those from original surgical specimens. The advantages of this animal model are as follows: 1. The explants retain their histotypical character for a long period. 2. Placement of the explants outside the dorsum of a nude rat makes serial observation and measurement easier. 3. Agents under test can be injected into the explants through a catheter inserted into a single pedicle of island flap without the possibility of spreading systematically.

Baccilary angiomatosis: negative results using normal Balb/c and Balb/c nude mice

Baccilary angiomatosis has recently been described as a disease that can spread systematically and that is potentially fatal. It is caused by Bartonella henselae and B. quintana, and presents as especially pronounced signs and symptoms in patients suffering from acquired immunodeficiency syndrome (AIDS). To clarify the pathogenesis of the disease and to try to define the relationships among baccilary angiomatosis, cat scratch disease and Carrión's bartonellosis, the authors of this study have attempted to develop an experimental model using mice that were immunocompetent as well as those that had their cellular immunity genetically compromised. A know concentration of B. henselae was inoculated intradermally in Balb/c an isogenic mice or an athymic group of the same lineage. Blood samples were taken on days-0, 3, 7, 10, 14, 28, and 60 after inoculation for indirect immunofluorescence antibody testing. On the 21st and 60th day, one animal from each group was sacrificed and a post mortem carried out including histological evaluation of the liver, spleen, lymph nodes, skin and other organs. Hemocultures of the sacrificed animals were collected. All results of serologic response, cultures and histologic examination were negative. The authors discuss the methodology, especially the use of isogenic animals of the same lineage in B. henselae infection, with and without immunodeficiency, and the resources for the negative results of histopathology, serology and cultures.

Development of Animal Model for Orthotopic Non-Small Cell Lung Cancer in Nude Rat / 대한흉부외과학회지

A major obstacles to evaluation of newly-developed treatment strategy for human lung cancer has been the lack of appropriate experimental animal models. We describe a new experimental model of orthotopically-developed non-small cell lung cancer in nude rat, involving inoculation of tumor cell suspension by thoracotomy. Over 40 direct implantation to the periphery of the lung has been performed to date, each requiring less than 1 hour for completion. This model has been used to perform a series of experiments to investigate whether the rat lung and surrounding structures trapped tumor cells with 2 different non-small cell lung cancer cell lines(NCI-H460 and NCI-H1299). Every animal showed development of tumor masses, which were loculated at the periphery of the lung paren- chyma and identified also by radiography. After 3 weeks of the inoculation, tumor develop ment at the mediastinal strutures were identified. The life expectancies of the victims were different between the cell lines, but were approximately 5 weeks when NCI-H460 cell line was used. This new orthotopic lung cancer model may be facilitate future studies of the new therapeutics of localized non-small cell lung cancer .

Rol del gen SPARC en la capacidad tumorigénica de células de melanoma humano / The role of SPARC gene in tumorigenic capacity of human melanoma cells

En un estudio previo demostramos que líneas celulares y tumores de melanoma humano expresan altos niveles de la proteína de matriz extracelular SPARC. Para determinar su rol en la progresión del melanoma humano, la línea IIB-MELLES fue transfectada con el cDNA de SPARC anti-sentido. Se aislaron tres clones con expresión disminuida de SPARC. Ninguno de ellos mostró cambios en la cinética de crecimiento in vitro comparado con las células control. La inyección s.c. de células control en ratones atímicos mostró desarrollo tumoral en el 100 por ciento de los animales, mientras que ninguno de los clones dio origen a tumores. Estos estudios demuestran que SPARC podría jugar un rol central en la progresión del melanoma humano.

Aspectos morfológicos do epitélio uterino de ratas nude atímicas nas fases de proestro e de metaestro do ciclo estral / Morphological characteristics of the uterine epithelium of athimic nude rats, in the proestrus and metestrus phases of estrous cycle

O presente experimento compara a nível de microscopia de luz a morfologia do epitélio uterino de ratas congenitamente atímicas (rnu/rnu) com a de suas "littermtes" eutímicas (rnu/ +), da linhagen Rowett, nas fases de proestro e de metaestro do ciclo estral. Pudemos observar que a morfologia do epitélio uterino das ratas homozigotas (rnu/rnu) foi semelhante à das heterozigotas (rnu/ +), em ambas as fases estudadas e compatível com a morfologia uterina descrita na literatura referente a ratas comuns. No metaestro verificamos epitélio do tipo cilíndrico simples e áreas deste epitélio em desarranjo com algumas das células apresentando vacuolizaçäo citoplasmática e núcleo picnótico. No proestro, o epitélio cilíndrico simples apresentou-se constituído por células contendo núcleo alongado deslocado para a porçäo basal