Evaluating Disease Patterns of Military Working Dogs in the Republic of Korea: A Retrospective Study.

The purpose of this study was to evaluate disease patterns among military working dogs (MWDs) at the Armed Forces Medical Research Institute (AFMRI) to provide basic medical data on Korean MWDs. The medical records of procedures performed at AFMRI between November 2017 and March 2021 were reviewed. Physical examination, diagnostic imaging, and laboratory tests were performed according to the status of each dog. A total of 353 MWDs (215 males and 138 females; mean age, 6 ± 3 years) were analyzed in this study. Among Korean MWDs, gastrointestinal (GI) disorders are the most frequently diagnosed, followed by dental and musculoskeletal disorders. Foreign body (FB) ingestion had the highest prevalence of GI disorders, with the most common FB being a leather collar or leash. General and dental surgeries, including removal of gastric FB and tooth extraction, were routinely performed at the AFMRI. Preventative care focusing on dental disease and FB ingestion may be helpful for effective performance and good quality of life in MWDs, with the regular assessment and prevention of environmental factors that may contribute to behavioral problems such as FB ingestion, coprophagy, and anorexia.

Comparison of Serum Bile Acid Concentrations Between Maltese and Other Breeds of Dogs With Portosystemic Shunt.

BACKGROUND/AIM: Congenital portosystemic shunt (PSS) is a vascular anomaly forming a direct communication between portal and central venous systems, thus bypassing the liver. This condition is related to various clinical symptoms including those manifesting in the central nervous system, gastrointestinal tract, and urinary tract. Treatment of PSS includes medical management and surgery. When evaluating prognosis of dogs with PSS, serum biochemistry profiles including serum bile acid (SBA) and ammonia concentrations are routinely used as screening tests. However, the use of SBA concentration in Maltese is controversial because it can be measured above the reference range even in normal dogs of this breed. In addition, utilizing SBA levels to assess surgical prognosis of PSS is not widely understood in this breed. Thus, the present study evaluated whether SBA could be used as a screening test for PSS in Maltese dogs. MATERIALS AND METHODS: Medical records of dogs in the Veterinary Teaching Hospital from 2018 to 2020 were retrospectively reviewed. RESULTS: A total of 23 dogs with PSS and 30 Maltese dogs without PSS were analyzed. Although preoperative SBA levels were significantly higher in Maltese dogs (192 µmol/l) than in other dog breeds (137 µmol/l) with portocaval shunt, its concentrations were significantly decreased after surgery in both Maltese and other breeds of dogs. No significant difference was observed in postoperative SBA levels between Maltese and other dog breeds. The mean SBA levels for Maltese dogs without PSS (8 µmol/l) were within the reference interval (0-25 IU/l). CONCLUSION: Measuring pre- and post-operative SBA levels to evaluate prognosis of PSS might also be available for Maltese.

Application of a Modified Dorsal Wiring Method in Toy Breed Dogs With Atlantoaxial Subluxation.

BACKGROUND/AIM: Atlantoaxial subluxation (AAS) is a congenital or traumatic condition that often requires surgical stabilization. Surgery is performed via a ventral or dorsal approach. A ventral approach is challenging in toy breed dogs due to their small-sized bones. Reducing AAS by orthopedic wire via a dorsal approach can cause iatrogenic spinal cord damage. Due to these limitations, a Kishigami atlantoaxial tension band (Kishigami AATB) that remains in the epidural space has been devised. Similar to the Kishigami AATB, the present study developed a modified dorsal wiring method and evaluated it in toy breed dogs with AAS. MATERIALS AND METHODS: Medical data of toy breed dogs with AAS that underwent surgical stabilization using the modified dorsal wiring method from 2017 to 2020 were retrospectively reviewed. RESULTS: A total of 10 dogs were analyzed. Regarding the history of these dogs, six dogs had congenital AAS, and the remaining four dogs had traumatic AAS. Evaluation via computed tomography was available for five dogs, of which two dogs were identified as having incomplete ossification of their atlas. Although four dogs required a revision surgery because of recurrence of clinical signs or fracture of the atlas, final functional improvement was achieved in nine dogs. One dog showed worsened neurological status that led to death. CONCLUSION: Clinical results with the modified dorsal wiring method were similar to those with the Kishigami AATB. The modified dorsal wiring method is versatile as it could be applied to various shapes of dogs' atlas. Considering the shape of the atlas, it is recommended to apply the implant as far from the midline of the dorsal arch as possible to avoid fractures. With selection of suitable patients, this modified dorsal wiring method can be applied to dorsal stabilization of AAS in toy breed dogs.

Radiographic Evaluation of Atlas and Axis Anomalies in Toy Breed Dogs With and Without Atlantoaxial Subluxation.

BACKGROUND/AIM: Atlantoaxial subluxation (AAS) is generally a congenital condition that mainly affects toy breed dogs. Previous studies in several toy breed dogs revealed that dogs with AAS had a relatively high proportion of incomplete ossification (IO) of the atlas and dens anomalies compared to dogs without AAS. These anatomical characteristics may be important in surgical decision-making. Thus, the present study evaluated morphological differences in the atlas and axis between Maltese dogs with and without AAS. MATERIALS AND METHODS: The medical records of Maltese dogs with and without AAS from 2015 to 2020 were analyzed. Abnormalities of the atlas and axis were evaluated using computed tomography (CT). RESULTS: A total of 45 dogs were reviewed. Maltese dogs with AAS revealed a higher ratio of IO of the atlas (56%) than non-affected dogs (19%). Dens anomalies were identified in 78% of the dogs with AAS and in 26% of non-affected dogs. The shape of the atlas has been identified as thin, solid compact bone in Maltese dogs. Dogs that revealed IO of the dorsal arch of the atlas showed significantly lower CT values (in Hounsfield units) than dogs without IO. The CT values of the midline of the dorsal arch were significantly lower than those of the outer surrounding region. Dens hypoplasia was defined by measuring the dens-to-axis length ratio according to a previous study. A significantly lower ratio was identified in dogs with AAS than in non-affected dogs. CONCLUSION: The incidence ratio of abnormalities of the atlas and axis in Maltese dogs with AAS was similar to that of previous studies. The dorsal arch of the atlas is composed of thin cortical bone with a vulnerable midline region. As dogs with AAS are more likely to be afflicted with abnormalities in the atlas and axis, considering these morphological features is important when planning the surgical stabilization of AAS.

Congenital portosystemic shunt concurrent with an atrial septal defect in a Maltese dog.

BACKGROUND: Portosystemic shunt and atrial septal defect (ASD) are generally congenital diseases in dogs. Rarely, dogs with congenital vascular anomalies could be related to other vascular anomalies. CASE DESCRIPTION: A 1-year-old male Maltese dog, neutered and weighing 1.7 kg, was brought in for an additional assessment of a congenital portosystemic shunt (CPSS). CPSS was diagnosed as portocaval shunt by computed tomography. Surgical attenuation was performed. Although prognosis after CPSS attenuation was good, the dog was presented with exercise intolerance 1 year after the operation. Thoracic radiographs observed generalized cardiomegaly. Echocardiography revealed pulmonary hypertension and right-to-left shunting ASD. CONCLUSION: The present study reports a rare case of CPSS concurrent with ASD in a dog. As dogs with CPSS might have been associated with other vascular anomalies; therefore, echocardiography is recommended for early diagnosis of other cardiovascular anomalies.

Long-term follow-up of a cat with an undetermined osteoporotic bone disease managed with multiple intramedullary pins.

CASE SUMMARY: Osteogenesis imperfecta (OI) is an inherited disorder related to the synthesis of type 1 collagen. Clinical signs of pain from the fracture of fragile bones are common. A 3-month-old male Chinchilla cat was presented for lameness and pain from a right femoral fracture. After surgical repair using intramedullary pins, and since repeated fractures occurred and there is little information about genes causing OI in cats, various examinations were performed to discriminate other diseases that could cause the pathological fracture. Primary hyperparathyroidism and nutritional or renal secondary hyperparathyroidism were ruled out through blood tests and ultrasonography. Quantitative CT confirmed low trabecular bone mineral density compared with normal cats. Radiography and histopathological examination revealed thin cortical bone. OI was tentatively diagnosed and long-term follow-up of the surgical repair was reviewed. Fractures were treated using intramedullary Kirschner wires. The same method of intramedullary pinning was then applied preventively to protect several other long bones by improving stress distribution and bending resistance. Follow-up was performed for 3 years until the patient's death due to undetermined reasons. RELEVANCE AND NOVEL INFORMATION: Although the patient underwent repeated fractures and bone unions, and needed medication for pain management sometimes, it was generally able to live as a companion cat. Therefore, palliative preventive intramedullary pinning could be used for long-term management of patients suspected of OI.

Tissue engineered ultra-thin descemet stripping corneal endothelial layers using porcine cornea and stem cells.

Due to their very poor proliferative capacity, the dysfunction of corneal endothelial cells can sometimes lead to incurable eye diseases that require corneal transplantation. Although many studies have been performed to reconstruct corneal endothelial cells, corneal transplantation is still considered to be the established approach. In this study, we developed bio-engineered Descemet stripping endothelial (DSE) layers, using porcine cornea and induced pluripotent stem cell (iPSC)-derived corneal endothelial cells (iCECs). First, we optimized a protocol to prepare an ultra-thin and decellularized Descemet stripping (DS) scaffold from porcine cornea. Our DS layers show over 90% transparency compared to the control. Porcine-derived cells and xenogenic antigens disappeared, whereas the collagen matrix remained in the graft. Next, corneal endothelial cell lines or iCECs were seeded on the decellularized DS graft and cultured for 7 days. The drying method reduced graft rolling and edema, and increased transparency during culture. The reseeded cells were evenly distributed over the graft, and most of the cells survived. Although future clinical studies are warranted, engineered DSE tissues using xenogenic tissues and stem cells will be useful tools for the treatment of incurable corneal diseases.

In-vitro Morphological Assessment of Apoptosis Induced by Nimbolide; A Limonoid from Azadirachta Indica (Neem Tree).

The present study was designed to investigate the in-vitro morphological assessment of apoptotic effect caused by nimbolide on the selected cancer cell lines (DU-145, PC-3, A-549) and normal cell lines (NIH3T3, CCD-18Co). The cells were grown in 6 well tissue culture plates after treatment with different concentrations of nimbolide and untreated control cells. Apoptotic and necrotic cells were measured using Hoechst 33342 and propidium iodide dual staining through a fluorescent microscope and also by staining with annexin V and propidium iodide through flow cytometric analysis. The activity of caspase 3, 8, and 9 was measured by caspases colorimetric assay kits. The number of apoptotic and necrotic cells were significantly higher in all selected cancer cell lines treated with nimbolide as compared with untreated control cells, whereas in normal cell lines no significant difference was observed between nimbolide treated and untreated cells. The activity of caspase 3, 8, and 9 was also significantly higher in all cancer cell lines treated with nimbolide as compared with untreated control cells while it did not change significantly in normal cell lines as compared with untreated control. The results of the present study suggested that nimbolide induced apoptosis only in cancer cells without affecting the normal cells and one of the apoptosis inducing mechanism is through the activation of caspases signaling pathways. Therefore, nimbolide may be a novel promising candidate as an anticancer drug in future.

Nimbolide Represses the Proliferation, Migration, and Invasion of Bladder Carcinoma Cells via Chk2-Mediated G2/M Phase Cell Cycle Arrest, Altered Signaling Pathways, and Reduced Transcription Factors-Associated MMP-9 Expression.

Nimbolide, an active chemical constituent of Azadirachta indica, reportedly has several physiological effects. Here, we assessed novel anticancer effects of nimbolide against bladder cancer EJ and 5637 cells. Nimbolide treatment inhibited the proliferation of both bladder cancer cell lines with an IC50 value of 3 µM. Treatment of cells with nimbolide induced G2/M phase cell cycle arrest via both Chk2-Cdc25C-Cdc2/cyclin B1-Wee1 pathway and Chk2-p21WAF1-Cdc2/cyclin B1-Wee1 pathway. Nimbolide increased JNK phosphorylation and decreased p38MAPK and AKT phosphorylation. Additionally, nimbolide impeded both wound healing migration and invasion abilities by suppressing matrix metalloproteinase-9 (MMP-9) activity. Finally, nimbolide repressed the binding activity of NF-κB, Sp-1, and AP-1 motifs, which are key transcription factors for MMP-9 activity regulation. Overall, our study indicates that nimbolide is a potential chemotherapeutic agent for bladder cancer.

Evaluation of Hypertriglyceridemia as a Mediator Between Endocrine Diseases and Pancreatitis in Dogs.

The role of hypertriglyceridemia (HTG) secondary to endocrine diseases in the occurrence of pancreatitis in dogs has not been fully investigated. The objective of the present study was to evaluate HTG as a mediator between endocrine diseases and pancreatitis in dogs. The study design was a retrospective case-control study. Medical records of dogs newly diagnosed with acutely presenting pancreatitis between 2012 and 2014 were reviewed for the presence or absence of hyperadrenocorticism (HAC), diabetes mellitus (DM), and hypothyroidism. A matched case-control analysis was performed, and the association between endocrine diseases and pancreatitis was evaluated using multiple logistic regression analysis. In dogs with pancreatitis, the odds of HAC (P < .001) and DM (P < .001) were 4.5 and 12.4 times that of dogs without pancreatitis, respectively. HTG significantly mediated the association between DM and pancreatitis but not between HAC and pancreatitis. Additional studies will be necessary to confirm these findings and to further elucidate the associations between endocrine diseases and pancreatitis.

Evaluation of Immunosuppressive Therapy Use for Tracheal Transplantation with Trachea-Mimetic Bellows Scaffolds in a Rabbit Model.

The objective of this study was to evaluate the use of immunosuppressive therapy with high-dose cyclosporine, high-dose azathioprine, and a combination of low-dose cyclosporine and azathioprine after tracheal reconstruction by using a trachea-mimetic graft of polycaprolactone (PCL) bellows-type scaffold in a rabbit model. Twenty-four healthy New Zealand white rabbits were used in the study. All underwent circumferential tracheal replacement using tissue-engineered tracheal graft, prepared from PCL bellows scaffold reinforced with silicone ring, collagen hydrogel, and human turbinate mesenchymal stromal cell (hTMSC) sheets. The control group (Group 1) received no medication. The three experimental groups were given daily cyclosporine intramuscular doses of 10 mg/kg (Group 2), azathioprine oral doses of 5 mg/kg (Group 3), and azathioprine oral doses of 2.5 mg/kg plus cyclosporine intramuscular doses of 5 mg/kg (Group 4) for 4 weeks or until death. Group 1 had longer survival times compared to Group 2 or Group 3. Each group except for Group 1 experienced decreases in amount of nutrition and weight loss. In addition, compared with the other groups, Group 2 had significantly increased serum interleukin-2 and interferon-γ levels 7 days after transplantation. The results of this study showed that the administration of cyclosporine and/or azathioprine after tracheal transplantation had no beneficial effects. Furthermore, the administration of cyclosporine had side effects, including extreme weight loss, respiratory distress, and diarrhea. Therefore, cyclosporine and azathioprine avoidance may be recommended for tracheal reconstruction using a native trachea-mimetic graft of PCL bellows-type scaffold in a rabbit model.

In vitro comparative cytotoxic effect of Nimbolide: A limonoid from Azadirachta indica (Neem tree) on cancer cell lines and normal cell lines through MTT assay.

The present study was conducted to find the cytotoxicity in vitro of nimbolide, limonoids derivative of flowers and leaves from Azadirachta indica (neem tree) on the selected cell lines of cancer (Du-145, PC-3, A-549) and normal fibroblast cell lines (NIH3T3, CCD-18Co) using MTT assay. The cells were seeded in 96 multi-well tissue plate using different concentrations of nimbolide for 24hrs and 48hrs. The percentage of viability of cell lines was calculated by optical density obtained by micro plate reader and cytotoxic effect in term of IC50 value was determined by using linear regression analysis. The percentages of viability of cells treated with different concentrations of nimbolide were significantly lower (P<0.05) than the untreated cancer cell lines while in normal cell lines no significant difference (P>0.05) between treated and the non-treated cells was observed. Nimbolide exerted time and dose dependent cytotoxic effect on the cancer lines and mild effect on the normal cell lines. It was further confirmed through PKH 26. Results of the present study suggested nimbolide as a potent chemotherapeutic and chemopreventive agent as it exerted a more cytotoxic effect on cancer cell lines as compared with the normal cell lines. Nimbolide may be a new hope as an anticancer drug in future.

Cortisol Levels and Gastrointestinal Disorders After Stressful Surgery in Rabbits.

Rabbits are widely used in biomedical studies because they are docile and manageable. However, they are prone to gastrointestinal disorders due to their vulnerability to stress. Eighteen adult rabbits were used for allogenic tracheal surgery. The tracheas for allograft, 20-mm length, were transplanted into 20-mm tracheal defects. Immediately after surgery, most rabbits suffered from poor appetite. Food and water intake gradually recovered within 7 days after surgery, but six rabbits had severe anorexia from day 7 post-surgery. Four of these rabbits developed symptoms of diarrhea after surgery; three of them died several days after the onset of diarrhea, while one rabbit recovered. Gastrointestinal disorders need to be prevented in rabbits undergoing stressful surgery. Furthermore, it is important to choose the proper type and dose of analgesics in order to relieve postoperative pain. With this observation in mind, rabbits are not considered to be an appropriate model for stressful surgery.

HSP70-1 is required for interleukin-5-induced angiogenic responses through eNOS pathway.

We report a pivotal role for IL-5 as an angiogenic activator. IL-5 increased proliferation, migration and colony tube formation in HUVECs associated with the phosphorylation of ERK and AKT/eNOS, and promoted microvessel sprouting from an angiogenesis animal model. The angiogenic effects were confirmed in IL-5-deficient mice and addition of IL-5 antibody. HSP70-1 was identified via expression profiling following IL-5 stimulation. A siRNA knockdown of HSP70-1 suppressed angiogenic responses and eNOS phosphorylation induced by IL-5. HSP70-1 overexpression enhanced IL-5-induced angiogenic responses. In addition, IL-5-induced neo-vascular formation was verified in both HSP70-1 knockout and HSP70-1 transgenic mice. Furthermore, transcription factor AP-1 was a main factor in IL-5-induced HSP70-1 in response to ERK and AKT signaling pathway. Angiogenic responses induced by VEGF had no effect in either HSP70-1 siRNA in vitro or HSP70-1 knockout mice. IL-5-induced angiogenic responses depended on the binding of IL-5Rα. Our data demonstrate that binding of IL-5 to IL-5Rα receptors enhances angiogenic responses by stimulating the expression of HSP70-1 via the eNOS signaling pathway.

Effects of neural stem cells and 5-fluorocytosine in canine metastatic lung tumor.

This is the first case report to describe the tumor regressive effect of systemic human neural stem cell (NSC)/5-fluorocytosine (5-FC) therapy on canine metastatic lung tumor. The therapeutic effects appeared approximately two weeks after 5-FC administration. Thoracic radiographs revealed a reduced number of lung nodules and decreased nodule size. However, there were no significant antitumor effects on primary lesions in abdominal organs. In conclusion, human NSC/5-FC prodrug therapy can secure patient quality of life with the same or more therapeutic effects and fewer side effects than other recommended chemotherapies.

Evaluation of Bone Regeneration on Polyhydroxyethyl-polymethyl Methacrylate Membrane in a Rabbit Calvarial Defect Model.

This study was conducted to evaluate the capacity of guiding bone regeneration of polyhydroxyethyl-polymethyl methacrylate (PHEMA-PMMA) membrane as a guided tissue regeneration membrane for bone defects. Two 8-mm diameter transosseous round defects were made at the parietal bone of 18 New Zealand White rabbits. Defects were covered with or without PHEMA-PMMA membrane. Radiological and histological evaluation revealed that the bone tissue over the defect was more regenerated with time in both groups. However, there was significantly more bone regeneration at 8 weeks in the experimental group than the control group (p<0.05). There was no sign of membrane degradation or tissue inflammation and no invasion of muscle and fibrous tissue into defects. PHEMA-PMMA is a potential material for guided tissue regeneration membrane as it induces no adverse tissue reaction and effectively supports selective bone regeneration.

Comparative Effects of Human Neural Stem Cells and Oligodendrocyte Progenitor Cells on the Neurobehavioral Disorders of Experimental Autoimmune Encephalomyelitis Mice.

Since multiple sclerosis (MS) is featured with widespread demyelination caused by autoimmune response, we investigated the recovery effects of F3.olig2 progenitors, established by transducing human neural stem cells (F3 NSCs) with Olig2 transcription factor, in myelin oligodendrocyte glycoprotein- (MOG-) induced experimental autoimmune encephalomyelitis (EAE) model mice. Six days after EAE induction, F3 or F3.olig2 cells (1 × 10(6)/mouse) were intravenously transplanted. MOG-injected mice displayed severe neurobehavioral deficits which were remarkably attenuated and restored by cell transplantation, in which F3.olig2 cells were superior to its parental F3 cells. Transplanted cells migrated to the injured spinal cord, matured to oligodendrocytes, and produced myelin basic proteins (MBP). The F3.olig2 cells expressed growth and neurotrophic factors including brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), ciliary neurotrophic factor (CNTF), and leukemia inhibitory factor (LIF). In addition, the transplanted cells markedly attenuated inflammatory cell infiltration, reduced cytokine levels in the spinal cord and lymph nodes, and protected host myelins. The results indicate that F3.olig2 cells restore neurobehavioral symptoms of EAE mice by regulating autoimmune inflammatory responses as well as by stimulating remyelination and that F3.olig2 progenitors could be a candidate for the cell therapy of demyelinating diseases including MS.

Ultrastructural comparison of porcine putative embryonic stem cells derived by in vitro fertilization and somatic cell nuclear transfer.

The ultrastructure of porcine putative embryonic stem cells and porcine fetal fibroblasts (PFFs) was analyzed by transmission electron microscopy. The aim of this study was to compare the features of organelles in in vitro fertilization (IVF) derived porcine embryonic stem cells (IVF-pESCs) and somatic cell nuclear transfer (SCNT) derived pESCs (SCNT-pESCs). Also, the features of organelles in high-passage IVF-pESCs were compared with those in low-passage cells. The ultrastructure of PFFs showed rare microvilli on the cell surfaces, polygonal or irregular nuclei with one to two reticular-shaped nucleoli and euchromatin, low cytoplasm-to-nucleus ratios, rare ribosomes, rare rough endoplasmic reticulum, elongated mitochondria, rich lysosomes and rich phagocytic vacuoles. IVF-pESCs showed rare microvilli on the cell surfaces, round or irregular nuclei with one to two reticular-shaped nucleoli and euchromatin, low cytoplasm-to-nucleus ratios, rich ribosomes, long stacks of rough endoplasmic reticulum, elongated mitochondria, rare lysosomes and rare autophagic vacuoles. By contrast, SCNT-pESCs showed rich microvilli with various lengths and frequencies on the cell surfaces, polygonal nuclei with one reticular shaped nucleoli and heterochromatin, high cytoplasm-to-nucleus ratios, rare ribosomes, rare rough endoplasmic reticulum, round mitochondria, rich lysosomes and rich phagocytic vacuoles with clear intercellular junctions. Furthermore, high-passage IVF-pESCs showed irregularly shaped colonies, pyknosis and numerous lysosomes associated with autophagic vacuoles showing signs of apoptosis. In conclusion, this study confirms that the ultrastructural characteristics of pESCs differ depending on their origin. These ultrastructural characteristics might be useful in biomedical research using pESCs, leading to new insights regarding regenerative medicine and tissue repair.

Evaluation of stability and biocompatibility of PHEMA-PMMA keratoprosthesis by penetrating keratoplasty in rabbits.

Artificial corneas have been developed as an alternative to natural donor tissue to replace damaged or diseased corneas. This study was conducted to evaluate the stability and biocompatibility of PHEMA-PMMA [poly (2-hydroxyl methacrylate)-poly (methyl methacrylate)] keratoprostheses in rabbits following penetrating keratoplasty. Sixteen male New Zealand White rabbits aged 16 weeks were divided into three groups. Group I and group II contained six rabbits each, while the control group had four rabbits. Experimental surgery was conducted under general anesthesia. The cornea was penetrated using an 8 mm diameter biopsy punch. In group I (core 5 mm & skirt 3 mm) and group II (core 6 mm & skirt 2 mm), the keratoprosthesis was placed into the recipient full thickness bed and sutured into position with double-layer continuous. In the control group, corneal transplantation using normal allogenic corneal tissue was performed with the same suture method. After four and eight weeks, keratoprosthesis devices were evaluated by histopathological analysis of gross lesions. Post-operative complications were observed, such as extrusion and infection in experimental groups. Most corneas were maintained in the defect site by double-layer continuous suture materials for 4 weeks and kept good light transmission. However, most artificial cornea were extruded before 8 weeks. Overall, combined PHEMA and PMMA appears to have sufficient advantages for production of artificial corneas because of its optical transparency, flexibility and other mechanical features. However, the stability and biocompatibility were not sufficient to enable application in humans and animals at the present time using penetrating keratoplasty. Further studies are essential to improve the stability and biocompatibility with or without other types of keratoplasty.

Temporal Evolution of MRI Characteristics in Dogs with Collagenase-Induced Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) is one of the most lethal types of stroke. Neuroimaging techniques, particularly MRI, have improved the diagnostic accuracy of ICH. The MRI characteristics of the evolving stages of ICH in humans-but not those in dogs-have been described. In this study, we document the temporal MRI characteristics in a canine model of collagenase-induced ICH. Specifically, ICH was induced in 5 healthy beagles by injecting 500 U of bacterial collagenase from Clostridium histolyticum, which was delivered into the parietal lobe over 5 min by using a microinfusion pump. T1- and T2-weighted, fluid-attenuated inversion recovery, gradient-echo (GRE), and diffusion-weighted (DWI) imaging and measurement of the apparent diffusion coefficient (ADC) were performed serially at 6 different time points (before and 12 h, 3 d, 5 d, 10 d and 24 d after hemorrhage) by using a 3-T MR system. The temporal changes of T1 signal intensity (SI) corresponded well with the reported human data. The temporal changes of T2 and GRE sequences, with the exception of T2 and GRE hyperintensities at the early subacute stage, also matched. ADC measurements were high at the early subacute stage, and DWI-SI positively correlated with T2- and GRE-SI from the early subacute stage onward. In conclusion, MRI is an ideal method for characterizing the temporal evolution of parenchymal alterations after ICH in dogs. These data might be useful for differentiating clinical stages of ICH in dogs.