Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Diabetes Metab J ; 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38772544

RESUMO

Background: Islet transplantation holds promise for treating selected type 1 diabetes mellitus patients, yet the scarcity of human donor organs impedes widespread adoption. Porcine islets, deemed a viable alternative, recently demonstrated successful longterm survival without zoonotic risks in a clinically relevant pig-to-non-human primate islet transplantation model. This success prompted the development of a clinical trial protocol for porcine islet xenotransplantation in humans. Methods: A single-center, open-label clinical trial initiated by the sponsor will assess the safety and efficacy of porcine islet transplantation for diabetes patients at Gachon Hospital. The protocol received approval from the Gachon Hospital Institutional Review Board (IRB) and the Korean Ministry of Food and Drug Safety (MFDS) under the Investigational New Drug (IND) process. Two diabetic patients, experiencing inadequate glycemic control despite intensive insulin treatment and frequent hypoglycemic unawareness, will be enrolled. Participants and their family members will engage in deliberation before xenotransplantation during the screening period. Each patient will receive islets isolated from designated pathogen-free pigs. Immunosuppressants and systemic infection prophylaxis will follow the program schedule. The primary endpoint is to confirm the safety of porcine islets in patients, and the secondary endpoint is to assess whether porcine islets can reduce insulin dose and the frequency of hypoglycemic unawareness. Conclusion: A clinical trial protocol adhering to global consensus guidelines for porcine islet xenotransplantation is presented, facilitating streamlined implementation of comparable human trials worldwide.

3.
Sci Rep ; 11(1): 8617, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33883656

RESUMO

Many groups are working to improve the results of clinical allogeneic islet transplantation in a primate model. However, few studies have focused on the optimal islet dose for achieving normal glycemia without exogenous insulin after transplantation in primate models or on the relationship between rejection and islet amyloid polypeptide (IAPP) expression. We evaluated the dose (10,000, 20,000, and > 25,000 islet equivalents (IEQ)/kg) needed to achieve normal glycemia without exogenous insulin after transplantation using eleven cynomolgus monkeys, and we analyzed the characteristics exhibited in the islets after transplantation. 10,000 IEQ/kg (N = 2) failed to control blood glucose level, despite injection with the highest dose of exogenous insulin, and 20,000 IEQ/kg group (N = 5) achieved unstable control, with a high insulin requirement. However, 25,000 IEQ/kg (N = 4) achieved normal glycemia without exogenous insulin and maintained it for more than 60 days. Immunohistochemistry results from staining islets found in liver biopsies indicated that as the number of transplanted islets decreased, the amount of IAPP accumulation within the islets increased, which accelerated CD3+ T cell infiltration. In conclusion, the optimal transplantation dose for achieving a normal glycemia without exogenous insulin in our cynomolgus monkey model was > 25,000 IEQ/kg, and the accumulation of IAPP early after transplantation, which depends on the transplanted islet dose, can be considered one factor in rejection.


Assuntos
Diabetes Mellitus Experimental/imunologia , Insulina/imunologia , Ilhotas Pancreáticas/imunologia , Macaca fascicularis/imunologia , Animais , Complexo CD3/imunologia , Teste de Tolerância a Glucose/métodos , Imuno-Histoquímica/métodos , Polipeptídeo Amiloide das Ilhotas Pancreáticas/imunologia , Transplante das Ilhotas Pancreáticas/métodos , Transplante Heterólogo/métodos
4.
Case Rep Neurol ; 13(1): 35-39, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33613242

RESUMO

Influenza vaccines are known to have a few neurological complications, such as Guillain-Barre syndrome, chronic inflammatory demyelinating polyneuropathy, and acute disseminated encephalomyelitis. However, oculomotor palsy caused by influenza vaccination is extremely rare. We present a case report of a 25-year-old woman without any medical history who developed complete oculomotor palsy 2 weeks after influenza vaccination. Other possible causes of oculomotor nerve palsy, such as stroke, compressive lesions, infections, and autoimmune disorders, were eliminated by blood tests, cerebrospinal fluid examination, and imaging studies. Hence, influenza vaccine was considered as the likely cause.

5.
Sci Rep ; 10(1): 793, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31964980

RESUMO

The most obvious method to observe transplanted islets in the liver is direct biopsy, but the distribution and location of the best biopsy site in the recipient's liver are poorly understood. Islets transplanted into the whole liver of five diabetic cynomolgus monkeys that underwent insulin-independent survival for an extended period of time after allo-islet transplantation were analyzed for characteristics and distribution tendency. The liver was divided into segments (S1-S8), and immunohistochemistry analysis was performed to estimate the diameter, beta cell area, and islet location. Islets were more distributed in S2 depending on tissue size; however, the number of islets per tissue size was high in S1 and S8. Statistical analysis revealed that the characteristics of islets in S1 and S8 were relatively similar to other segments despite various transplanted islet dosages and survival times. In conclusion, S1, which exhibited high islet density and reflected the overall characteristics of transplanted islets, can be considered to be a reasonable candidate for a liver biopsy site in this monkey model. The findings obtained from the five monkey livers with similar anatomical features to human liver can be used as a reference for monitoring transplanted islets after clinical islet transplantation.


Assuntos
Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas , Fígado/citologia , Aloenxertos , Animais , Biópsia , Diabetes Mellitus Experimental/patologia , Feminino , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Insulina/metabolismo , Macaca fascicularis , Masculino
7.
Bioconjug Chem ; 29(9): 2945-2953, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-29985588

RESUMO

The microenvironment of pancreatic islets gets disrupted during enzyme digestion and causes islets to remain in a vulnerable state, leading to poor outcome in the initial days of transplantation. To avoid immune invasion while allowing the reconstruction of the microenvironment of the transplanted site, we propose immunoisolation polymers, which can nanoencapsulate islets quickly without cytotoxicity. Here, nonhuman primate (NHP) islets were nanoencapsulated with hyperbranched polyethylene glycol (hb-PEG) and heparin by layer-by-layer technology and transplanted into the kidney subcapsular space of diabetic C57BL/6 mice. An immunosuppressive drug protocol was applied to increase the survival time until the animals were sacrificed. The recipients of NHP islets exhibited high nonfasting blood glucose level (BGL) for 2-3 weeks, which was normalized afterward. Immunohistochemical (IHC) analysis revealed an immature vascular basement membrane and cell surface integrins directly associated with poor initial insulin production. The transplanted grafts regained their own microenvironment within a month without any outside stimuli. No lymphocyte infiltration was observed in the grafts at any time. Humoral and cell-mediated immune responses were prominently diminished by the hb-PEG/Heparin nanoencapsulated islets. Immunoisolation accompanied by an immunosuppressive drug protocol protects islets by helping them avoid immunogenesis while at the same time allowing them to reconstruct their microenvironment.


Assuntos
Glicemia/metabolismo , Microambiente Celular , Heparina/química , Transplante das Ilhotas Pancreáticas/métodos , Nanotecnologia , Polietilenoglicóis/química , Animais , Formação de Anticorpos , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/terapia , Imunidade Celular , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos C57BL
8.
Biomaterials ; 171: 164-177, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29698867

RESUMO

Intraportal pancreatic islet transplantation incurs huge cell losses during its early stages due to instant blood-mediated inflammatory reactions (IBMIRs), which may also drive regulation of the adaptive immune system. Therefore, a method that evades IBMIR will improve clinical islet transplantation. We used a layer-by-layer approach to shield non-human primate (NHP) islets with polyethylene glycol (nano-shielded islets, NSIs) and polyethylene glycol plus heparin (heparin nano-shielded islets; HNSIs). Islets ranging from 10,000 to 20,000 IEQ/kg body weight were transplanted into 19 cynomolgus monkeys (n = 4, control; n = 5, NSI; and n = 10, HNSI). The mean C-peptide positive graft survival times were 68.5, 64 and 108 days for the control, NSI and HNSI groups, respectively (P = 0.012). HNSI also reduced the factors responsible for IBMIR in vitro. Based on these data, HNSIs in conjunction with clinically established immunosuppressive drug regimens will result in superior outcomes compared to those achieved with the current protocol for clinical islet transplantation.


Assuntos
Heparina/química , Ilhotas Pancreáticas/fisiologia , Nanopartículas/química , Polímeros/química , Aloenxertos/fisiologia , Animais , Sobrevivência de Enxerto , Humanos , Fígado/patologia , Subpopulações de Linfócitos/metabolismo , Macaca fascicularis , Polietilenoglicóis/química
9.
Xenotransplantation ; 25(1)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29135052

RESUMO

BACKGROUND: Porcine islet xenotransplantation is considered an attractive alternative treatment for type 1 diabetes mellitus. However, it is largely limited because of initial rejection due to Instant Blood-Mediated Inflammatory Reaction (IBMIR), oxidative stress, and inflammatory responses. Recently, soluble tumor necrosis factor-ɑ receptor type I (sTNF-αR) and heme oxygenase (HO)-1 genes (HO-1/sTNF-αR) have been shown to improve the viability and functionality of porcine islets after transplantation. METHODS: In this study, genetically modified mesenchymal stem cells (MSCs) expressing the HO-1/sTNF-αR genes (HO-1/sTNF-αR-MSC) were developed using an adenoviral system, and porcine islet viability and function were confirmed by in vitro tests such as GSIS, AO/PI, and the ADP/ATP ratio after coculturing with HO-1/sTNF-αR-MSCs. Subsequently, isolated porcine islets were transplanted underneath the kidney capsule of diabetic humanized mice without MSCs, with MSCs or with HO-1/sTNF-αR-MSCs. RESULTS: According to the results, the HO-1/sTNF-αR-MSC-treated group exhibited improved survival of porcine islets and could reverse hyperglycemia more than porcine islets not treated with MSCs or islets cotransplanted with MSCs. Moreover, the HO-1/sTNF-αR-MSC group maintained its morphological characteristics and the insulin secretion pattern of transplanted porcine islets similar to endogenous islets in immunocompetent humanized mice. CONCLUSIONS: Our results suggest that HO-1/sTNF-αR-MSCs are efficient tools for porcine islet xenotransplantation, and this study may provide basic information for pre-clinical animal models and future clinical trials of porcine islet xenotransplantation.


Assuntos
Sobrevivência de Enxerto , Heme Oxigenase-1/genética , Xenoenxertos/imunologia , Proteínas de Membrana/genética , Células-Tronco Mesenquimais/citologia , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Animais , Técnicas de Cocultura , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/terapia , Sobrevivência de Enxerto/imunologia , Humanos , Fragmentos Fc das Imunoglobulinas/imunologia , Ilhotas Pancreáticas/imunologia , Transplante das Ilhotas Pancreáticas/métodos , Transplante de Células-Tronco Mesenquimais/métodos , Camundongos Transgênicos , Transplante Heterólogo/métodos
10.
Low Urin Tract Symptoms ; 7(1): 32-6, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26663649

RESUMO

OBJECTIVE: Patients with lower urinary tract symptoms (LUTS) have a higher prevalence of cardiovascular disease. We evaluated the correlation between LUTS and cardiovascular risk factors in men presenting with benign prostatic hyperplasia (BPH). METHODS: We retrospectively reviewed the medical records of 295 men with transurethral resection of the prostate for the treatment of BPH and LUTS. Risk factors for cardiovascular disease included: hypertension, diabetes mellitus (DM), smoking, and dyslipidemia. The severity of LUTS measured by the International Prostatic Symptom Score (IPSS), prostate volume, prostate specific antigen (PSA), maximal urinary flow rate (Qmax), and postvoid residual urine (PVR) in subjects with or without cardiovascular risk factors were compared. RESULTS: IPSS-total (22.9 ± 7.8 vs. 21.2 ± 7.3, P = 0.01) and obstructive symptom score (13.3 ± 5.2 vs. 11.9 ± 4.7, P = 0.01) was significantly different between men with hypertension and without cardiovascular risk factors. There was no significant difference of variables between subjects with DM, smoking or dyslipidemia and without cardiovascular risk factors. In the Pearson correlation, the systolic and diastolic blood pressure (BP) were related with prostate volume (r = 0.138, P = 0.040; r = 0.163, P = 0.020), IPSS-total (r = 0.139, P = 0.043; r = 0.138, P = 0.043), and an obstructive symptom score (r = 0.168, P = 0.014; r = 0.143, P = 0.037), respectively. CONCLUSIONS: Men with hypertension are more likely to have a higher IPSS and large prostate volume than men without hypertension. This finding implicates a pathophysiological association between hypertension and LUTS, and the need to manage comorbid symptoms simultaneously.


Assuntos
Hipertensão/complicações , Sintomas do Trato Urinário Inferior/etiologia , Hiperplasia Prostática/etiologia , Idoso , Idoso de 80 Anos ou mais , Humanos , Hipertensão/diagnóstico , Sintomas do Trato Urinário Inferior/diagnóstico , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/diagnóstico , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença
11.
Korean J Urol ; 55(7): 453-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25045443

RESUMO

PURPOSE: Systemic inflammatory responses, which are defined in terms of the Glasgow prognostic score (GPS), have been reported to be independent predictors of unfavorable outcomes in various human cancers. We assessed the utility of the GPS as a predictor of intravesical recurrence after radical nephroureterectomy (RNU) in upper urinary tract carcinoma (UTUC). MATERIALS AND METHODS: We collected data for 147 UTUC patients with no previous history of bladder cancer who underwent RNU from 2004 to 2012. Associations between perioperative clinicopathological variables and intravesical recurrence were analyzed by using univariate and multivariate Cox regression models. RESULTS: Overall, 71 of 147 patients (48%) developed intravesical recurrence, including 21 patients (30%) diagnosed with synchronous bladder tumor. In the univariate analysis, performance status, diabetes mellitus (DM), serum albumin, C-reactive protein, GPS, and synchronous bladder tumor were associated with intravesical recurrence. In the multivariate analysis, performance status (hazard ratio [HR], 2.33; 95% confidence interval [CI], 1.41-3.85; p=0.001), DM (HR, 2.04; 95% CI, 1.21-3.41; p=0.007), cortical thinning (HR, 2.01; 95% CI, 1.08-3.71; p=0.026), and GPS (score of 1: HR, 6.86; 95% CI, 3.69-12.7; p=0.001; score of 2: HR, 5.96; 95% CI, 3.10-11.4; p=0.001) were independent predictors of intravesical recurrence. CONCLUSIONS: Our results suggest that the GPS as well as performance status, DM, and cortical thinning are associated with intravesical recurrence after RNU. Thus, more careful follow-up, coupled with postoperative intravesical therapy to avoid bladder recurrence, should be considered in these patients.


Assuntos
Carcinoma de Células de Transição/cirurgia , Recidiva Local de Neoplasia/etiologia , Nefrectomia/métodos , Neoplasias Urológicas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células de Transição/patologia , Carcinoma de Células de Transição/secundário , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Ureter/cirurgia , Neoplasias da Bexiga Urinária/secundário , Neoplasias Urológicas/patologia
12.
Korean J Urol ; 54(5): 316-21, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23700497

RESUMO

PURPOSE: To determine predictive factors for stent failure-free survival in patients treated with a retrograde ureteral stent for a malignant ureteral obstruction. MATERIALS AND METHODS: We retrospectively reviewed 71 patients who underwent insertion of a cystoscopic ureteral stent due to a malignant ureteral obstruction between May 2004 and June 2011. Performance status, type of cancer, hydronephrosis grade, location of the obstruction, presence of bladder invasion, C-reactive protein (CRP), serum albumin, and inflammation-based prognostic score (Glasgow prognostic score, GPS) were assessed using a Cox proportional regression hazard model as predicting factors for stent failure. RESULTS: A univariate analysis indicted that hypoalbuminemia (<3.5 g/dL; hazard ratio [HR], 2.43; 95% confidence interval [CI], 1.21 to 4.86; p=0.012), elevated CRP (≥1 mg/dL; HR, 4.79; 95% CI, 2.0 to 11.1; p=0.001), and presence of a distal ureter obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.021) were associated with stent failure-free survival. A multivariate analysis revealed that the presence of a mid and lower ureteral obstruction (HR, 3.27; 95% CI, 1.19 to 8.95; p=0.007), GPS ≥1 (HR, 7.22; 95% CI, 2.89 to 18.0; p=0.001), and elevated serum creatinine before ureteral stent placement (>1.2 mg/dL; HR, 2.16; 95% CI, 1.02 to 4.57; p=0.044) were associated with stent failure-free survival. CONCLUSIONS: A mid or lower ureteral obstruction, GPS ≥1, and serum creatinine before ureteral stent insertion >1.2 mg/dL were unfavorable predictors of stent failure-free survival. These factors may help urologists predict survival time.

13.
Acta Ophthalmol Scand ; 85(7): 786-90, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17617200

RESUMO

PURPOSE: We investigated the effects of short-term exposure to triamcinolone on cultured choroidal fibroblast (CFB) cells and retinal pigment epithelial (RPE) cells. METHODS: To evaluate the effect of triamcinolone on cell proliferation, CFB and RPE cells were divided into three groups: a short-term exposure group; a longterm exposure group, and a non-treated control group. Cells in the short-term exposure group were briefly exposed (5, 15 or 30 mins) to triamcinolone (0.01 mg/ml, 1 mg/ml or mitomycin C (0.01 microg/ml, 1 microg/ml). Cells in the longterm exposure group were continuously incubated in culture medium containing the drug until assessment. The control group was cultured without drugs. Cell viability and the number of cells were assessed at day 5 after exposure. To investigate the direct toxicity of triamcinolone on confluent RPE cells, completely confluent cells were exposed to the drugs in the manner as described above. Cell viability was determined on days 0, 3 and 5 after treatment. RESULTS: In the short-term exposure group, 1 mg/ml triamcinolone caused a significant reduction in the proliferation of CFB and RPE cells. The proliferation of CFBs decreased even with exposure to 0.01 mg/ml triamcinolone. In the longterm exposure group, triamcinolone and mitomycin C reduced the proliferation of both CFB and RPE cells. Even very short periods of exposure to triamcinolone caused a significant reduction in the viability of completely confluent RPE cells. CONCLUSIONS: Even short periods of exposure to triamcinolone inhibited the proliferation of fibroblasts and RPE cells and were significantly toxic to completely confluent RPE cells.


Assuntos
Fibroblastos/efeitos dos fármacos , Glucocorticoides/toxicidade , Epitélio Pigmentado Ocular/efeitos dos fármacos , Triancinolona Acetonida/toxicidade , Animais , Animais Recém-Nascidos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Corioide/citologia , Mitomicina/toxicidade , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...