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2.
Intern Med J ; 46(12): 1380-1385, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27549746

RESUMEN

BACKGROUND: End-stage renal disease is a common predisposing condition for the development of hypoglycaemia. AIM: To determine the effect of hypoglycaemia on the mortality of patients undergoing maintenance dialysis. METHODS: Retrospective and descriptive analyses were performed in five dialysis centres in the Republic of Korea between June 2002 and August 2008. We enrolled 1685 patients who had undergone dialysis for at least 1 month. RESULTS: We identified 453 episodes of hypoglycaemia in 256 of 1685 patients (15.2%); 189 patients (73.8%) had diabetes, whereas the other patients did not. The occurrence of hypoglycaemia in patients receiving dialysis appeared to be a life-threatening complication because 27.0% of patients died within two days of the onset of a hypoglycaemic episode. Older age, low serum albumin levels and infections were independent risk factors for total mortality in these patients. Furthermore, the absence of diabetes, age and serum glucose levels were independent factors associated with early mortality within two days of the development of hypoglycaemia. CONCLUSION: Although several factors were associated with mortality, the degree of hypoglycaemia, absence of diabetes and old age were associated with early mortality. Elderly hypoglycaemic patients, especially those without diabetes, should be closely monitored.


Asunto(s)
Hipoglucemia/sangre , Inflamación/sangre , Fallo Renal Crónico/sangre , Diálisis Renal/efectos adversos , Albúmina Sérica/metabolismo , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Hipoglucemia/etiología , Hipoglucemia/mortalidad , Inflamación/mortalidad , Fallo Renal Crónico/mortalidad , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Prevalencia , Pronóstico , Estudios Retrospectivos
3.
Opt Lett ; 39(3): 486-8, 2014 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-24487846

RESUMEN

We present a new class of coherent perfect absorbers based on guided-mode resonance in thin semiconductor films. Using particle-swarm optimization methods, we design a thin-film amorphous silicon grating that maximizes coherent modulation of the absorbance. The optimized device exhibits a maximum scattering power of ∼94% and a power absorption limit approaching 100% at the 1550-nm wavelength.

4.
Eur J Clin Microbiol Infect Dis ; 33(2): 259-64, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23996048

RESUMEN

Treatment of cirrhotic patients with spontaneous peritonitis using antibiotics occasionally fails. Fungal infections may be one of the causes of antibiotic treatment failure in such patients. In this study we evaluated the clinical significance and characteristics of spontaneous fungal peritonitis (SFP). Consecutive cirrhotic patients with spontaneous peritonitis treated between 2000 and 2005 at a tertiary care center in Seoul, Korea, were included. We analyzed the clinical characteristics and the prognosis of SFP patients compared with patients with spontaneous bacterial peritonitis (SBP). During the study period 416 patients developed spontaneous peritonitis and 15 (3.6 %) had SFP. Compared with patients with SBP, nosocomial peritonitis (peritonitis that developed after hospitalization for >72 h) was more common and the Child-Pugh score was higher in SFP patients (both, P < 0.01). Ten patients were infected with Candida spp. (C. albicans, 8; C. tropicalis, 1; C. glabrata, 1), and 5 with Cryptococcus neoformans. Eleven patients were co-infected with bacteria that were susceptible to the antibiotics administered. Only 5 patients were treated using appropriate anti-fungal agents. The 1-month mortality rate for SFP patients was 73.3 % (11 out of 15; median time to death, 2 days [range, 0-22]), which was significantly higher than patients with SBP alone (28.7 %, P = 0.0007). SFP is severe complication related to high mortality in cirrhotic patients. A longer admission and a higher Child-Pugh score may be risk factors. Immediate anti-fungal treatment is warranted in patients with spontaneous peritonitis, once fungus is found in the ascitic fluid.


Asunto(s)
Candida/aislamiento & purificación , Cryptococcus neoformans/aislamiento & purificación , Cirrosis Hepática/complicaciones , Micosis/epidemiología , Micosis/microbiología , Peritonitis/epidemiología , Peritonitis/microbiología , Adulto , Anciano , Bacterias/aislamiento & purificación , Candida/clasificación , Coinfección/epidemiología , Coinfección/microbiología , Coinfección/mortalidad , Coinfección/patología , Infección Hospitalaria/epidemiología , Infección Hospitalaria/microbiología , Infección Hospitalaria/mortalidad , Infección Hospitalaria/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Micosis/mortalidad , Micosis/patología , Peritonitis/mortalidad , Peritonitis/patología , Prevalencia , República de Corea/epidemiología , Análisis de Supervivencia , Centros de Atención Terciaria
5.
Diabetes Obes Metab ; 14(9): 795-802, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22443183

RESUMEN

AIM: Individuals requiring insulin therapy for type 2 diabetes often require escalation of their regimen to achieve glycaemic control. Optimal management strategies for uncontrolled type 2 diabetes would improve glycaemic control without hypoglycaemia and weight gain. This study compared the efficacy and tolerability of adding sitagliptin, an oral dipeptidyl peptidase-4 inhibitor, and an up to 20% increase in insulin dose in patients with uncontrolled type 2 diabetes on insulin therapy. METHODS: We conducted a 24-week, randomized, active-competitor, parallel-group study in subjects with uncontrolled type 2 diabetes [haemoglobin A1c (HbA1c) = 7.5-11%] currently using insulin therapy. Subjects were randomly assigned to either the sitagliptin adding (100 mg daily, n = 70) or an insulin-increasing arm (≥ 10% at week 12 and ≥ 10% at week 24, n = 70) while continuing other medications. RESULTS: Average baseline HbA1c was 9.2% in both groups. HbA1c decreased more at 24 weeks in the sitagliptin adding than the insulin-increasing arm (-0.6 ± 0.1% vs. -0.2 ± 0.1%, p < 0.01). Insulin was increased by 25% at 24 weeks in the insulin-increasing group. Hypoglycaemic events were less common and less severe in sitagliptin adding arm than insulin-increasing arm (7.0 vs. 14.3 events per patient-year, p < 0.05). Weight was stable in the sitagliptin adding subjects (68.6 ± 11.6 vs. 68.1 ± 11.4 kg) but increased in the insulin-increasing subjects (66.2 ± 10.6 vs. 67.4 ± 9.7 kg, p < 0.05). Other adverse events occurred at similar rates in both arms. CONCLUSIONS: Compared to a 25% increase in insulin dose, adding sitagliptin to an insulin-based regimen was more effective at lowering HbA1c and associated with less hypoglycaemia and weight gain over 24 weeks. CLINICAL TRIAL NUMBER: NCT01100125.


Asunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inhibidores de la Dipeptidil-Peptidasa IV/administración & dosificación , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Pirazinas/administración & dosificación , Triazoles/administración & dosificación , Adulto , Anciano , Peso Corporal , Inhibidores de la Dipeptidil-Peptidasa IV/efectos adversos , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Ayuno/sangre , Femenino , Hemoglobina Glucada/metabolismo , Humanos , Hipoglucemia/inducido químicamente , Hipoglucemiantes/efectos adversos , Insulina/efectos adversos , Masculino , Persona de Mediana Edad , Pirazinas/efectos adversos , Fosfato de Sitagliptina , Triazoles/efectos adversos , Circunferencia de la Cintura
6.
J Exp Med ; 143(5): 1170-85, 1976 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-177713

RESUMEN

Beta cells were isolated from strains of mice that were susceptible and resistant to encephalomyocarditis (EMC) viral-induced diabetes mellitus. Beta cells from susceptible mice that were infected in vivo with EMC virus showed higher viral titers, more severe degranulation, and lower concentrations of immunoreactive insulin than beta cells from resistant mice. Immunofluorescence and infectious center assays revealed that pancreas from susceptible mice contained at least 10 times more infected cells than pancreas from resistant mice. Beta cell cultures prepared from susceptible mice and infected in vitro also showed higher viral titers and more severe cytopathologic changes than beta cell cultures from resistant mice. In contrast to beta cell cultures, virus replicated equally well in primary embryo and kidney cell cultures from susceptible and resistant strains of mice. It is concluded that the development of EMC virus-induced diabetes is related to genetically determined host differences in the capacity of the virus to infect beta cells.


Asunto(s)
Diabetes Mellitus/etiología , Virus de la Encefalomiocarditis/crecimiento & desarrollo , Islotes Pancreáticos/microbiología , Replicación Viral , Animales , Células Cultivadas , Diabetes Mellitus/genética , Diabetes Mellitus/patología , Embrión de Mamíferos/microbiología , Genotipo , Insulina/análisis , Islotes Pancreáticos/análisis , Islotes Pancreáticos/patología , Riñón/microbiología , Ratones , Ratones Endogámicos , Especificidad de la Especie
7.
J Exp Med ; 148(4): 1068-80, 1978 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-212506

RESUMEN

Coxsackie virus B4 that had been passaged in cultures enriched for pancreatic beta cells produced a diabetes-like syndrome when inoculated into SJL/J mice. The infection resulted in insulitis and destruction of beta cells. Viral antigens were found in beta cells by staining with fluorescein-labeled antibody to Coxsackie virus B4. The destruction of beta cells led to a decrease in the immunoreactive insulin content of the pancreas and hypoinsulinemia. The reduction in immunoreactive insulin correlated inversely with the elevation of glucose in the blood and over 80% of the animals were found to be hyperglycemic within 14 days after infection. The percentage of animals with hyperglycemia decreased with time and at the end of 60 days, less than 5% of the animals were still hyperglycemic. However, many of the normoglycemic mice were found to be metabolically abnormal when evaluated by glucose tolerance tests. Studies on the susceptibility of the host showed that only certain inbred strains of mice became diabetic when infected with Coxsackie virus B4. It is concluded that both the passage history of the virus and the strain of the host influence the development of diabetes.


Asunto(s)
Infecciones por Coxsackievirus/complicaciones , Diabetes Mellitus/etiología , Islotes Pancreáticos/microbiología , Animales , Antígenos Virales/análisis , Enterovirus Humano B/inmunología , Hiperglucemia/etiología , Insulina/sangre , Ratones , Ratones Endogámicos/microbiología
8.
J Exp Med ; 152(4): 878-92, 1980 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-6252275

RESUMEN

Plaque purification of the M variant of encephalomyocarditis (EMC) virus resulted in the isolation of two stable variants: one diabetogenic and designated D and the other nondiabetogenic and designated B. When the D variant was inoculated into SJL/J male mice, hypoinsulinemia and hyperglycemia developed in > 90% of the animals. In contrast, none of the mice inoculated with the B variant developed diabetes. Histologic examination of pancreata from mice infected with the D variant revealed insulitis and necrosis of beta cells, whereas islets from mice infected with the B variant showed little, if any, change. When islets were assayed for infectious virus, approximately 10 times more virus was recovered from animals inoculated with the D as compared with the B variant. Moreover, approximately 60% of islet cells from mice infected with the D variant contained viral antigens when stained with fluorescein-labeled anti-EMC virus antibody, whereas < 5% of islet cells from animals infected with the B variant contained viral antigens. Co-infection experiments showed that the induction of diabetes by the D variant was inhibited by the B variant. When the B and D variants were mixed together at B:D ratios of 1, 9, and 99, diabetes developed in 60, 11, and 0% of the mice, respectively. Tissue-culture experiments revealed that the B variant induced considerably more interferon than the D variant, and studies in animals showed that interferon appeared earlier and in greater amounts in the circulation of mice infected with the B as compared with the D variant. These studies suggest that the induction of interferon by the B variant is, at least in part, responsible for the inhibition of diabetes by the D variant.


Asunto(s)
Diabetes Mellitus Experimental/microbiología , Virus de la Encefalomiocarditis/genética , Variación Genética , Animales , Antígenos Virales/genética , Glucemia/metabolismo , Virus de la Encefalomiocarditis/patogenicidad , Insulina/sangre , Masculino , Ratones , Páncreas/microbiología , Virulencia
9.
J Exp Med ; 189(2): 347-58, 1999 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-9892617

RESUMEN

We have shown previously that the inactivation of macrophages in nonobese diabetic (NOD) mice results in the prevention of diabetes; however, the mechanisms involved remain unknown. In this study, we found that T cells in a macrophage-depleted environment lost their ability to differentiate into beta cell-cytotoxic T cells, resulting in the prevention of autoimmune diabetes, but these T cells regained their beta cell-cytotoxic potential when returned to a macrophage-containing environment. To learn why T cells in a macrophage-depleted environment lose their ability to kill beta cells, we examined the islet antigen-specific immune response and T cell activation in macrophage-depleted NOD mice. There was a shift in the immune balance, a decrease in the T helper cell type 1 (Th1) immune response, and an increase in the Th2 immune response, due to the reduced expression of the macrophage-derived cytokine IL-12. As well, there was a deficit in T cell activation, evidenced by significant decreases in the expression of Fas ligand and perforin. The administration of IL-12 substantially reversed the prevention of diabetes in NOD mice conferred by macrophage depletion. We conclude that macrophages play an essential role in the development and activation of beta cell-cytotoxic T cells that cause beta cell destruction, resulting in autoimmune diabetes in NOD mice.


Asunto(s)
Autoinmunidad/inmunología , Macrófagos/inmunología , Animales , Diferenciación Celular/inmunología , Ácido Clodrónico/farmacología , Citotoxicidad Inmunológica/inmunología , Diabetes Mellitus/genética , Diabetes Mellitus/inmunología , Proteína Ligando Fas , Femenino , Interleucina-12/farmacología , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/inmunología , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos NOD , Páncreas/efectos de los fármacos , Páncreas/patología , Perforina , Proteínas Citotóxicas Formadoras de Poros , Bazo/inmunología , Linfocitos T/inmunología , Trasplante de Tejidos
10.
Am J Nephrol ; 31(3): 247-54, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20090311

RESUMEN

BACKGROUND: End-stage renal disease (ESRD) is simultaneously associated with inflammation, impaired immunity and increased susceptibility to microbial infections. Innate immune cells, monocytes and polymorphonuclear leukocytes (PMN) recognize pathogens via toll-like receptors (TLR) triggering phagocytosis, cellular activation and secretion of inflammatory cytokines. Data on expression and function of TLRs in ESRD are limited. METHODS: Blood samples from 21 stable ESRD patients and 21 normal controls were processed for TLR2, TLR4, TLR7 and TLR 9 expression on monocytes and PMN by flow cytometry. TLR activity was examined by determining the response to TLR4 and TLR2 ligands. RESULTS: The ESRD group exhibited significant upregulation of TLR2 and TLR4 (but not TLR7 or TLR 9) expressions on monocytes and of TLR4 on PMN. This was coupled with heightened cytokine production in response to TLR4 activation with lipopolysaccharide. However, the response to TLR2 stimulation with peptidoglycan was unchanged in the ESRD group. CONCLUSIONS: Monocyte TLR2 and TLR4 and neutrophil TLR4 expressions and TLR4 activity are increased hemodialysis patients, representing another dimension of ESRD-associated inflammation.


Asunto(s)
Inflamación/metabolismo , Fallo Renal Crónico/inmunología , Fallo Renal Crónico/metabolismo , Leucocitos/metabolismo , Receptores Toll-Like/metabolismo , Adulto , Nitrógeno de la Urea Sanguínea , Creatinina/sangre , Femenino , Humanos , Interleucina-6/sangre , Interleucina-8/sangre , Macrófagos/metabolismo , Masculino , Persona de Mediana Edad , Monocitos/metabolismo , Neutrófilos/metabolismo , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/metabolismo , Receptor Toll-Like 7/metabolismo , Receptor Toll-Like 9/metabolismo , Factor de Necrosis Tumoral alfa/sangre
11.
Br J Anaesth ; 105(5): 661-7, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20876698

RESUMEN

BACKGROUND: Although remifentanil provides profound analgesia during operation, postoperative occurrence of hyperalgesia and tolerance after remifentanil administration could be a challenge to the postoperative pain control. In this investigation, we sought to determine the effect of maintenance with propofol or sevoflurane on postoperative analgesia after remifentanil-based anaesthesia. METHODS: Two hundred and fourteen women undergoing breast cancer surgery under remifentanil-based general anaesthesia were randomly included in this prospective and double-blind trial. The patients were anaesthetized with sevoflurane (S) or propofol (P) under high (H) or low (L) effect-site concentration (Ce) of remifentanil-based anaesthesia using a target-controlled infusion system; the patients were allocated into the SH, SL, PH, and PL groups. Pain intensity (visual analogue score, VAS) and cumulative morphine requirements were recorded 30 min, 1, 6, 12, and 24 h after operation. RESULTS: The patient characteristics were similar. Cumulative morphine consumption at 24 h after surgery was higher in the SH group [38.6 (sd 14.9)] compared with the SL [31.5 (3.7)], PH [31.7 (8.3)], and PL groups [30.1 (6.1)] (P<0.001). The VAS scores during 24 h after surgery were also higher in the SH group than the SL, PH, and PL groups (P<0.001). CONCLUSIONS: Remifentanil hyperalgesia was induced by high dose of remifentanil-based anaesthesia during sevoflurane anaesthesia, whereas that was not apparent during propofol anaesthesia. Also, remifentanil hyperalgesia did not occur during low dose of remifentanil-based anaesthesia. Maintenance of propofol during high-dose remifentanil-based anaesthesia provided better postoperative analgesia.


Asunto(s)
Analgésicos Opioides/efectos adversos , Neoplasias de la Mama/cirugía , Hiperalgesia/inducido químicamente , Dolor Postoperatorio/prevención & control , Piperidinas/efectos adversos , Adulto , Anciano , Analgésicos Opioides/administración & dosificación , Anestésicos por Inhalación/farmacología , Anestésicos Intravenosos/farmacología , Método Doble Ciego , Esquema de Medicación , Interacciones Farmacológicas , Femenino , Humanos , Éteres Metílicos/farmacología , Persona de Mediana Edad , Morfina/administración & dosificación , Dimensión del Dolor/métodos , Propofol/farmacología , Estudios Prospectivos , Remifentanilo , Sevoflurano
12.
Science ; 201(4355): 529-31, 1978 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-208156

RESUMEN

Reovirus type 3, passaged in pancreatic beta-cell cultures, produced an insulitis when inoculated into 1- to 2-week-old mice. By means of a double-label antibody technique, in which we used fluorescein-labeled antibody to reovirus and rhodamine-labeled antibody to insulin, reovirus antigens were found in beta cells. By electron microscopy, viral particles in different stages of morphogenesis were observed in insulin-containing beta cells but not glucagon-containing alpha cells. The infection resulted in destruction of beta cells, reduction in the insulin content of the pancreas, and alteration in the host's capacity to respond normally to a glucose tolerance test.


Asunto(s)
Diabetes Mellitus Experimental/microbiología , Islotes Pancreáticos/microbiología , Infecciones por Reoviridae/complicaciones , Animales , Antígenos Virales/análisis , Células Cultivadas , Diabetes Mellitus Experimental/etiología , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/microbiología , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Orthoreovirus Mamífero 3/inmunología , Ratones , Replicación Viral
13.
Science ; 284(5417): 1183-7, 1999 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-10325232

RESUMEN

Glutamic acid decarboxylase (GAD) is a pancreatic beta cell autoantigen in humans and nonobese diabetic (NOD) mice. beta Cell-specific suppression of GAD expression in two lines of antisense GAD transgenic NOD mice prevented autoimmune diabetes, whereas persistent GAD expression in the beta cells in the other four lines of antisense GAD transgenic NOD mice resulted in diabetes, similar to that seen in transgene-negative NOD mice. Complete suppression of beta cell GAD expression blocked the generation of diabetogenic T cells and protected islet grafts from autoimmune injury. Thus, beta cell-specific GAD expression is required for the development of autoimmune diabetes in NOD mice, and modulation of GAD might, therefore, have therapeutic value in type 1 diabetes.


Asunto(s)
Autoantígenos/inmunología , Diabetes Mellitus Tipo 1/enzimología , Diabetes Mellitus Tipo 1/inmunología , Glutamato Descarboxilasa/inmunología , Islotes Pancreáticos/enzimología , Traslado Adoptivo , Animales , Autoantígenos/genética , Autoantígenos/fisiología , Autoinmunidad , ADN sin Sentido , Diabetes Mellitus Tipo 1/patología , Femenino , Expresión Génica , Glutamato Descarboxilasa/genética , Glutamato Descarboxilasa/fisiología , Insulina/sangre , Insulina/metabolismo , Islotes Pancreáticos/inmunología , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Trasplante de Islotes Pancreáticos , Activación de Linfocitos , Masculino , Ratones , Ratones Endogámicos NOD , Ratones SCID , Ratones Transgénicos , Linfocitos T/inmunología , Transgenes
14.
J Appl Microbiol ; 107(4): 1119-30, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19486422

RESUMEN

AIMS: Isomaltulose (palatinose) is a slowly digestible sucrose isomer that can reduce both the glycemic and insulinemic response to foods. The aim of this study was to clone and express a sucrose isomerase (SIase) gene and characterize the protein that is responsible for the production of isomaltulose in the micro-organism Enterobacter sp. FMB-1. METHODS AND RESULTS: A cosmid clone containing c. 6 kbp region encoding an SIase gene was identified. The 5969-bp chromosomal DNA fragment covering the SIase (esi) gene in Enterobacter sp. FMB-1 was sequenced. Although this DNA fragment contained several open reading frames other than esi, only the presence of esi was sufficient to produce isomaltulose in recombinant Escherichia coli. The esi gene was expressed in E. coli, leading to the characterization of its SIase activity. CONCLUSIONS: The Enterobacter sp. FMB-1 esi gene was successfully cloned and expressed in E. coli. This gene encoded a functional SIase that produced isomaltulose from sucrose. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first molecular analysis of an SIase gene in an Enterobacter strain. The functional expression of the Enterobacter sp. FMB-1 esi gene in E. coli offers an alternative choice for the industrial production of isomaltulose.


Asunto(s)
Clonación Molecular , Enterobacter/enzimología , Genes Bacterianos , Transferasas Intramoleculares/genética , Isomaltosa/análogos & derivados , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Cromatografía en Capa Delgada , ADN Bacteriano/genética , Enterobacter/genética , Regulación Bacteriana de la Expresión Génica , Biblioteca de Genes , Transferasas Intramoleculares/metabolismo , Isomaltosa/genética , Isomaltosa/metabolismo , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
15.
J Natl Cancer Inst ; 56(4): 757-62, 1976 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-176408

RESUMEN

Chromosome preparations were made of bone marrow cells and peripheral lymphocytes isolated from chicks that developed leukemia following infection with JM-V herpes-virus. Karyotypic analysis revealed a high frequency of chromosome breaks and aneuploidy, as well as some pulverization of chromosomes. The number of chromosome breaks began to increase at 2-3 days post infection, and by 5 days post infection it reached 12.7% of bone marrow cells and 17.2% of peripheral lymphocytes. Similarly, the number of aneuploid metaphase figures increased rapidly and reached 12% of bone marrow cells and 19% of peripheral lymphocytes at 5 days post infection. Some specificity was observed in the chromosomes that were affected.


Asunto(s)
Virus de la Leucosis Aviar , Aberraciones Cromosómicas , Herpesviridae , Leucemia Experimental/genética , Aneuploidia , Animales , Médula Ósea/ultraestructura , Células de la Médula Ósea , Leucemia Experimental/etiología , Leucemia Linfoide/genética , Linfocitos/ultraestructura , Factores de Tiempo
16.
Cryo Letters ; 27(4): 223-34, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16990950

RESUMEN

The applicability of cryopreservation protocols to a broad range of genotypes is a key issue for genebanks. We tried to identify the critical factors causing differences in survival of cryopreserved shoot tips using potato varieties coming from cultivated and wild species. The droplet-vitrification method, a combination of droplet-freezing and solution-based vitrification, was selected from several protocols. High survival after freezing was observed after dehydration with PVS2 for 20 min, cooling shoot tips placed in a droplet of PVS2 solution on aluminum foil strips by immersing the foil strips in liquid nitrogen, warming them by plunging the foil strips into a 0.8 M sucrose solution (at 40 degrees C) for 30 s and unloading in 0.8 M sucrose for 30 min. This optimized protocol was successfully applied to 12 accessions with survival ranging between 64.0 and 94.4%.


Asunto(s)
Criopreservación/métodos , Brotes de la Planta/fisiología , Solanum/genética , Solanum/fisiología , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Conservación de los Recursos Naturales , Crioprotectores/farmacología , Medios de Cultivo/farmacología , Técnicas de Cultivo/métodos , Relación Dosis-Respuesta a Droga , Genotipo , Glicerol/farmacología , Brotes de la Planta/citología , Brotes de la Planta/efectos de los fármacos , Solanum/citología , Sacarosa/farmacología , Temperatura , Factores de Tiempo
17.
Diabetes ; 42(3): 435-43, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8381754

RESUMEN

The best experimental evidence indicating that viruses have an etiological role in the pathogenesis of diabetes comes from studies of mice infected with EMC virus. For this study we generated mutant viruses from stocks of diabetogenic EMC-D and nondiabetogenic EMC-B viruses by serial passages of the viruses in L-cell cultures at high MOI. The genomic sequence information and the biological activities of three different plaque-purified diabetogenic variants of EMC virus (EMC-D, EMC-D1/6A, EMC-D2/4) and six different plaque-purified nondiabetogenic variants (EMC-B, EMC-BS, EMC-B1/G, EMC-DV1, EMC-D4/1B, EMC-D3/1) revealed that only one amino acid, Ala (776th amino acid on the polyprotein), is critical for the diabetogenicity of EMC virus. The G base at the nucleotide position 3155 (Ala[GCC]776 in the polyprotein) is unique to all diabetogenic variants, whereas the A base at the same position (Thr[ACC]776 in the polyprotein) is identical to all nondiabetogenic variants. A single-point mutation (G to A; Ala to Thr) results in the conversion of the diabetogenic variant into a nondiabetogenic variant of EMC virus. On the basis of these observations, we conclude that a single amino acid, Ala776, on the polyprotein of EMC virus appears responsible for the inducement of diabetes in susceptible mice. Conversion of Ala776 into Thr776 on the polyprotein by a point mutation, G to A at the nucleotide position 3155, results in the loss of diabetogenicity.


Asunto(s)
Cápside/genética , Diabetes Mellitus Tipo 1/microbiología , Virus de la Encefalomiocarditis/genética , Alanina , Animales , Secuencia de Bases , Proteínas de la Cápside , ADN Viral/genética , Masculino , Ratones , Datos de Secuencia Molecular , Mutación
18.
Diabetes ; 41(8): 998-1008, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1628775

RESUMEN

Six CD4+ and three CD8+ islet-reactive T-cell clones were established from lymphocytes infiltrating the pancreatic islets of NOD mice. Two of six CD4+ T-cell clones responded to NOD islet cells only, not to spleen cells. The remaining four clones responded to both islet cells and spleen cells from NOD mice, but not to cells from other strains of mice, including SJL, C3H, C57BL/6, and DBA/2 mice. None of the CD4+ T-cell clones had a cytotoxic effect on the cultured islet cells. On the other hand, all of the CD8+ T-cell clones showed both a proliferative response and a cytotoxic effect on the islet cells, with the restriction of MHC class I H-2Db. Electron microscopic studies revealed that islet-specific CD4+ T-cells attached closely to islet cells but did not destroy them. In contrast, CD8+ T-cell clones showed pseudopodialike protrusions into beta-cells, but not alpha- or delta-cells, leading to selective destruction of beta-cells. CD8+ CTLs could not be isolated from islets of NOD mice less than 10 wk of age, even if the islets showed lymphocytic infiltration, whereas CD4+ T-cells could be isolated from islets of these younger NOD mice. On the basis of these observations, we concluded that CD4+ and CD8+ T-cells interact differently with beta-cells at different stages in T-cell--mediated beta-cell destruction. CD4+ T-cells may secrete cytokines, which in turn activate effector cell populations, whereas CD8+ T-cells may act as a final effector directly involved in beta-cell destruction.


Asunto(s)
Autoinmunidad/fisiología , Islotes Pancreáticos/inmunología , Linfocitos T/inmunología , Animales , Antígenos CD4/inmunología , Antígenos CD8/inmunología , Citotoxicidad Inmunológica/fisiología , Citometría de Flujo , Técnicas In Vitro , Islotes Pancreáticos/ultraestructura , Complejo Mayor de Histocompatibilidad/inmunología , Ratones , Ratones Endogámicos NOD , Ratones Endogámicos , Linfocitos T/ultraestructura
19.
Diabetes ; 37(12): 1722-6, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2847947

RESUMEN

The administration of cyclophosphamide to nonobese diabetic (NOD) male mice produces a rapid progression to overt diabetes (greater than 70%) with severe insulitis in 2-3 wk, whereas none of the untreated control NOD male mice became diabetic. When the thin sections of islets from the NOD male mice, which received silica for the preservation of islets and subsequently cyclophosphamide, were examined under the electron microscope, clusters of endogenous retrovirus-like particles (type A) were frequently found in the beta-cells. In contrast, retrovirus-like particles were rarely found in the beta-cells from NOD male mice that received only silica. Other endocrine cells, including alpha-, delta-, pancreatic polypeptide-producing, and exocrine acinar cells, did not contain such viruslike particles. These viruslike particles were also not found in spleen, liver, or kidney in either cyclophosphamide-treated or untreated NOD male mice. There was a clear correlation between the presence of retrovirus-like particles in the beta-cells and insulitis lesions in the cyclophosphamide-treated mice. On the basis of these observations, we conclude that the beta-cell-specific expression of endogenous retrovirus (like particles) is associated with the development of insulitis and diabetes in NOD mice.


Asunto(s)
Diabetes Mellitus Experimental/microbiología , Islotes Pancreáticos/microbiología , Ratones Mutantes , Infecciones por Retroviridae/complicaciones , Animales , Ciclofosfamida/farmacología , Diabetes Mellitus Experimental/etiología , Inflamación , Islotes Pancreáticos/patología , Masculino , Ratones , Microscopía Electrónica
20.
Diabetes ; 40(12): 1586-97, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1661690

RESUMEN

A single administration of complete Freund's adjuvant (CFA), type 1 carrageenan (Car), or silica 7, 2, and 2 days, respectively, before infection with a low dose (1 x 10(2) plaque-forming units/mouse) of encephalomyocarditis D (EMC-D) virus resulted in a significant increase in the incidence of diabetes in SJL/J mice (100%) compared with untreated EMC-D virus-infected mice (40%). Peritoneal macrophages were isolated from uninfected SJL/J mice, which had been treated once with silica, and transferred into SJL/J mice 2 days before low-dose EMC-D infection. Approximately 90% of the mice became diabetic, whereas 30% of mice that received virus alone became diabetic. The depletion of macrophages by treatment with the combined anti-Mac-1 and anti-Mac-2 monoclonal antibodies after a single administration of CFA, Car, or silica resulted in almost complete prevention of beta-cell destruction in EMC-D virus-infected mice. Furthermore, none of the mice in which macrophages were depleted by long-term treatment with silica and 10% of the mice treated with Car before virus infection became diabetic. On the basis of these observations, we conclude that macrophages are directly involved in the destruction of beta-cells, leading to the development of clinical diabetes in EMC-D virus-infected mice.


Asunto(s)
Diabetes Mellitus Experimental/fisiopatología , Virus de la Encefalomiocarditis/patogenicidad , Islotes Pancreáticos/patología , Macrófagos/fisiología , Animales , Anticuerpos Monoclonales/inmunología , Carragenina/administración & dosificación , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Experimental/patología , Técnica del Anticuerpo Fluorescente , Adyuvante de Freund/administración & dosificación , Insulina/análisis , Anticuerpos Insulínicos , Islotes Pancreáticos/microbiología , Células L , Activación de Macrófagos , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos , Dióxido de Silicio/administración & dosificación
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