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BACKGROUND: Little is known about the therapeutic benefits of a value-based healthcare model compared to a traditional activity-based incentive model in psoriasis (PsO). OBJECTIVES: This prospective non-interventional study evaluated an outcome-based, patient-centred management model for patients with PsO. METHODS: In total, 49 patients with a Psoriasis Area and Severity Index (PASI) ≥3 who were starting or switching between treatments were included. Patients were assessed at baseline, 3 and 9 months. The patient benefit index (PBI) was calculated using predefined questionnaires. An expected PBI was calculated and adjusted for risk factors known to complicate treatment, that is overweight and smoking. The model remunerated the department on whether the observed PBI exceeded the expected PBI to incentivize over-performance. RESULTS: In total, 40 patients (80%) completed all three visits; 32.7% were smokers and 73.5% were overweight. Mean PASI at baseline was 11.5 (SD 9.1); PASI improved significantly from baseline through 3 months: mean reduction, 8.0 (SD 9.2), p < 0.001 and was maintained until 9 months: mean further reduction, 0.1 (SD 3.3), p = 0.893. The mean PBI was 2.5 (SD 1.3) and 2.8 (SD 1.1) at 3 and 9 months, respectively. A PBI ≥1 was achieved by 87.8% at 3 and 95.1% at 9 months. Overall, the department was remunerated a mean 2721.1 DKK (SD 4472.8) per patient. In subgroup analysis, the department was remunerated a mean of, respectively, 2428.6 (SD 5089.5), 2636.6 (SD 4471.3) and 3196.5 (SD 4497.1) DKK for patients with none, 1 or 2 risk factors, that is smoking or/and overweight. CONCLUSIONS: The model evaluated herein is the first value-based model to calculate remuneration from patient reported outcomes and showed to successfully predict the expected PBI and remunerate treatment based on whether the expected treatment goal was met or exceeded. This can be utilized in the patient-centred management of PsO.
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PURPOSE: Shear wave elastography (SWE), as a tool for diagnosing thyroid malignancy, has gathered considerable attention during the past decade. Diverging results exist regarding the diagnostic performance of thyroid SWE. METHODS: A comprehensive literature review of thyroid SWE was conducted using the terms "Thyroid" and "shear wave elastography" in PubMed. RESULTS: The majority of studies found SWE promising for differentiating malignant and benign thyroid nodules on a group level, whereas results are less convincing on the individual level due to huge overlap in elasticity indices. Further, there is lack of consensus on the optimum outcome reflecting nodule elasticity and the cut-off point predicting thyroid malignancy. While heterogeneity between studies hinders a clinically meaningful meta-analysis, the results are discussed in a clinical perspective with regard to applicability in clinical practice as well as methodological advantages and pitfalls of this technology. CONCLUSION: Technological as well as biological hindrances seem to exist for SWE to be clinically reliable in assessing benign and malignant thyroid nodules. Structural heterogeneity of thyroid nodules in combination with operator-dependent factors such as pre-compression and selection of scanning plane are likely explanations for these findings. Standardization and consensus on the SWE acquisition process applied in future studies are needed for SWE to be considered a clinically reliable diagnostic tool for detection of thyroid cancer.
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Diagnóstico por Imagen de Elasticidad/métodos , Nódulo Tiroideo/patología , Animales , Diagnóstico Diferencial , Estudios de Evaluación como Asunto , Humanos , Nódulo Tiroideo/clasificación , Nódulo Tiroideo/diagnóstico por imagenRESUMEN
In the last decades, several endangered breeds of livestock species have been re-established effectively. However, the successful revival of the Dutch and Danish Landrace goats involved crossing with exotic breeds and the ancestry of the current populations is therefore not clear. We have generated genotypes for 27 FAO-recommended microsatellites of these landraces and three phenotypically similar Nordic-type landraces and compared these breeds with central European, Mediterranean and south-west Asian goats. We found decreasing levels of genetic diversity with increasing distance from the south-west Asian domestication site with a south-east-to-north-west cline that is clearly steeper than the Mediterranean east-to-west cline. In terms of genetic diversity, the Dutch Landrace comes next to the isolated Icelandic breed, which has an extremely low diversity. The Norwegian coastal goat and the Finnish and Icelandic landraces are clearly related. It appears that by a combination of mixed origin and a population bottleneck, the Dutch and Danish Land-races are separated from the other breeds. However, the current Dutch and Danish populations with the multicoloured and long-horned appearance effectively substitute for the original breed, illustrating that for conservation of cultural heritage, the phenotype of a breed is more relevant than pure ancestry and the genetic diversity of the original breed. More in general, we propose that for conservation, the retention of genetic diversity of an original breed and of the visual phenotype by which the breed is recognized and defined needs to be considered separately.
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Cabras/clasificación , Cabras/genética , Repeticiones de Microsatélite , Animales , Conservación de los Recursos Naturales , Femenino , Masculino , FilogeografíaRESUMEN
Mapping of QTL affecting fur quality traits (guard hair length, guard hair thickness, density of wool, surface of the fur and quality) and skin length was performed in a three-generation mink population (F2 design). In the parental generation, Nordic Brown mink were crossed reciprocally with American Black short nap mink. In all, 1082 mink encompassing three generations were used for the analyses. The mink were genotyped for 104 microsatellites covering all 14 autosomes. The QTL analyses were performed by least-square regression implemented in gridqtl software. Genetic and phenotypic correlations and heritabilities were estimated using the average information-restricted maximum-likelihood method. Evidence was found for QTL affecting fur quality traits on nine autosomes. QTL were detected for guard hair thickness on chromosomes 1, 2, 3, 6 and 13; for guard hair length on chromosomes 2, 3 and 6; for wool density on chromosomes 6 and 13; for surface on chromosomes 7, 12 and 13; for quality on chromosomes 6, 7, 11 and 13; and for skin length on chromosomes 7 and 9. Proximity of locations of QTL for guard hair length, guard hair thickness and for wool density and quality suggests that some of the traits are in part under the influence of the same genes. Traits under the influence of QTL at close or identical positions also were traits that were strongly genotypically correlated. Based on the results of correlation analyses, the most important single traits influencing the quality were found to be density of wool, guard hair thickness and appearance of the surface.
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Cabello , Visón/genética , Sitios de Carácter Cuantitativo , Animales , Mapeo Cromosómico , Ligamiento Genético , Genotipo , Repeticiones de Microsatélite , FenotipoRESUMEN
BACKGROUND: Radioiodine (131I) therapy is widely used for treatment of non-toxic goiters. A limitation for this treatment is a low thyroid radioiodine uptake (RAIU), often encountered in these patients. AIM: To estimate the impact of various factors on the thyroid RAIU. METHODS: We examined prospectively 170 patients (146 females; age range: 22-87 yrs) with nodular goiter (median 64 ml, range: 20-464 ml) selected for 131I therapy. Serum TSH was sub-normal in 42.4%. None were treated with anti-thyroid drugs. The thyroid RAIU was determined at 24h and 96 h. The goiter volume was measured by ultrasound (no.=127), or by magnetic resonance imaging (no.=43). RESULTS: The 24h and the 96 h RAIU were 34.2 ± 9.8(SD)% (range: 11.4-66.0%) and 34.0 ± 10.0% (range: 10.5-60.9%), respectively. Sixty-one patients had a 24h RAIU <30% and these individuals were older than patients with a 24h RAIU ≥ 30% (median 58 vs 51 yrs, p=0.02). These two subgroups did not differ significantly in other variables. Overall, the 24h RAIU was positively correlated to the serum (s) free T4-index (r=0.20, p=0.01), and negatively to age (r=-0.18, p=0.02), but not significantly related to serum TSH or thyroid volume. Age correlated positively with thyroid volume (r=0.31, p < 0.001). In a regression analysis, s-free T4-index and age remained as the only determinants of the 24h and the 96 h RAIU. CONCLUSIONS: In patients with a symptomatic nodular goiter, serum T4 and age are the major determinants of the thyroid RAIU. A sub-normal serum TSH is not a marker of a compromised thyroid RAIU but reflects that the iodine is confined to a few 'hot spots'.
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Envejecimiento/fisiología , Bocio Nodular/metabolismo , Radioisótopos de Yodo/metabolismo , Glándula Tiroides/metabolismo , Glándula Tiroides/patología , Tirotropina/sangre , Tiroxina/sangre , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Bocio Nodular/patología , Bocio Nodular/radioterapia , Humanos , Radioisótopos de Yodo/uso terapéutico , Persona de Mediana Edad , Estudios Prospectivos , Pruebas de Función de la Tiroides , Glándula Tiroides/efectos de la radiación , Adulto JovenRESUMEN
Inbreeding is an increasing problem in farmed mink, because of limited exchange of individuals between farms. In this study, genetic relatedness within seven American mink (Neovison vison) colour strains originating from 13 different mink farms in Denmark was analysed using 21 polymorphic microsatellite loci. We detected large differences in the level of relatedness (range 0.017-0.520) within colour strains. Moreover, a very strong and highly significant negative correlation between the level of relatedness and fecundity was observed (r = 0.536, P < 0.001) [Correction added after online publication on 9 March 2011: r(2) has been changed to r]. To our knowledge, this is the first time that such a correlation has been demonstrated for commercially farmed mink.
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Fertilidad/genética , Variación Genética , Endogamia , Visón/genética , Visón/fisiología , Análisis de Varianza , Animales , Teorema de Bayes , Cruzamiento/métodos , Dinamarca , Fertilidad/fisiología , Marcadores Genéticos/genética , Genotipo , Cabello/fisiología , Heterocigoto , Repeticiones de Microsatélite/genética , Pigmentación/genética , Pigmentación/fisiología , Especificidad de la Especie , Estados UnidosRESUMEN
Venomous snake bite and subsequent coagulopathy is a significant source of morbidity and mortality worldwide. The gold standard to treat coagulopathy caused by these venoms is the administration of antivenom; however, despite this therapy, coagulopathy still occurs and recurs. Of interest, our laboratory has demonstrated in vitro and in vivo that coagulopathy-inducing venom exposed to carbon monoxide (CO) is inhibited, potentially by an attached heme. The present investigation sought to determine if venoms derived from snakes of the African genera Atheris, Atractaspis, Causus, Cerastes, Echis, and Macrovipera that have no or limited antivenoms available could be inhibited with CO or with the metheme-inducing agent, O-phenylhydroxylamine (PHA). Assessing changes in coagulation kinetics of human plasma with thrombelastography, venoms were exposed in isolation to CO or PHA. Eight species were found to have procoagulant activity consistent with the generation of human thrombin, while one was likely fibrinogenolytic. All venoms were significantly inhibited by CO/PHA with species-specific variation noted. These data demonstrate indirectly that the heme is likely bound to these disparate venoms as an intermediary modulatory molecule. In conclusion, future investigation is warranted to determine if heme could serve as a potential therapeutic target to be modulated during treatment of envenomation by hemotoxic enzymes.
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Antivenenos/farmacología , Coagulación Sanguínea/efectos de los fármacos , Hemo/metabolismo , Hidroxilaminas/farmacología , Compuestos Organometálicos/farmacología , Venenos de Víboras/toxicidad , Animales , Humanos , Tromboelastografía , ViperidaeRESUMEN
Lameness is an important factor for culling animals. Strong legs and feet improve herd life of dairy cows. Therefore, many countries include leg and feet conformation traits in their breeding programs, often as early predictors of longevity. However, few countries directly measure lameness related traits to include these in a breeding program. Lameness indices in 3 different lactations and 5 leg conformation traits (rear legs side view, rear legs rear view, hock quality, bone quality, and foot angle) were measured on granddaughters of 19 Danish Holstein grandsires with 33 to 105 sons. A genome scan was performed to detect quantitative trait loci (QTL) based on the 29 autosomes using microsatellite markers. Data were analyzed across and within families for QTL affecting lameness and leg conformation traits. A regression method and a variance component method were used for QTL detection. Two QTL each for lameness in the first [Bos taurus autosome (BTA); BTA5, BTA26] and second (BTA19, BTA22) lactations were detected. For the 5 different leg conformation traits, 7 chromosome-wise significant QTL were detected across families for rear legs side view, 5 for rear legs rear view, 4 for hock quality, 4 for bone quality, and 1 for foot angle. For those chromosomes where a QTL associated with 2 different traits was detected (BTA1, BTA11, BTA15, BTA26, and BTA27), a multitrait-1-QTL model and a multitrait-2-QTL model were performed to characterize these QTL as single QTL with pleiotropic effects or distinct QTL.
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Enfermedades de los Bovinos/genética , Bovinos/anatomía & histología , Bovinos/genética , Cojera Animal/genética , Extremidad Inferior/anatomía & histología , Sitios de Carácter Cuantitativo/genética , Animales , Dinamarca , Femenino , Marcadores Genéticos , Variación Genética , Masculino , Modelos GenéticosRESUMEN
Hypofibrinogenemia is an important clinical consequence following envenomation by Lachesis muta muta, usually attenuated or prevented by administration of antivenom. The venom of L. m. muta contains both a metalloproteinase fibrinogenase and a serine protease thrombin-like enzyme, and exposure of fibrinogen to iron (Fe) and carbon monoxide (CO) has been demonstrated to decrease its catalysis by such enzymes. Using thrombelastographic analytical techniques, it was determined that this venom displayed weak procoagulant effects combined with fibrinogenolytic effects, and pretreatment of plasma with Fe and CO markedly attenuated venom-mediated effects. Additional experiments involving heparin exposure and varying calcium concentrations demonstrated that modification of fibrinogen with Fe and CO in human plasma rendered fibrinogen not recognizable to the fibrinogenolytic metalloproteinase but did not prevent polymerization by the thrombin-like serine protease. Lastly, when venom was exposed to CO in isolation and then placed in plasma, the fibrinogenase was inhibited but the thrombin-like enzyme was not inhibited. In sum, utilizing relatively facile modifications, we demonstrated with thrombelastography that Fe and/or CO addition can protect human plasmatic coagulation from fibrinogenase activity but not the effects of the thrombin-like activity of L. m. muta venom.
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Antivenenos/farmacología , Coagulación Sanguínea/efectos de los fármacos , Monóxido de Carbono/farmacología , Hierro/farmacología , Venenos de Víboras/toxicidad , Viperidae , Animales , Fibrinógeno/metabolismo , Humanos , Metaloendopeptidasas/toxicidad , Plasma/efectos de los fármacos , Plasma/fisiología , Serina Proteasas/toxicidad , TromboelastografíaRESUMEN
The aims of this study were (1) to confirm previously identified quantitative trait loci (QTL) on bovine chromosomes 6, 11, 14, and 23 in the Danish Holstein cattle population, (2) to assess the pleiotropic nature of each QTL on milk production traits by building multitrait and multi-QTL models, and (3) to include pedigree information on nongenotyped individuals to improve the estimation of genetic parameters underlying the random QTL model. Nineteen grandsire families were analyzed by single-trait (ST) and multitrait (MT) QTL mapping methods. The variance component-based QTL mapping model was implemented via restricted maximum likelihood (REML) to estimate QTL position and parameters. Segregation of the previously identified QTL was confirmed on bovine chromosomes 6, 11, and 14, but not on 23. A highly significant (1% chromosome-wise level) QTL was found on chromosome 6, between 37 and 73 cM. This QTL had a strong effect on protein percentage (PP) and fat percentage (FP) according to ST analyses, and effects on PP, FP, milk yield (MY), fat yield (FY), and protein yield (PY) in MT analyses. A QTL affecting PP was detected on chromosome 11 (at 70 cM) using ST analysis. The MT analysis revealed a second QTL (at 67 cM) approaching significance with an effect on MY. The ST analysis identified a QTL for MY and FP on chromosome 14, between 10 and 24 cM. The extended pedigree (nongenotyped animals) was included to estimate genetic parameters underlying the random QTL model; that is, additive polygenic and QTL variances. In general, the estimates of the QTL variance components were smaller but more precise when the extended pedigree was considered in the analysis.
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Bovinos/genética , Lactancia/genética , Sitios de Carácter Cuantitativo/genética , Animales , Cruzamiento , Mapeo Cromosómico/métodos , Mapeo Cromosómico/veterinaria , Dinamarca , Femenino , Marcadores Genéticos , Variación Genética , Genotipo , Modelos Lineales , Masculino , LinajeRESUMEN
Thousands suffer poisonous snake bite, often from defibrinogenating species annually. Three rattlesnake species in particular, the timber rattlesnake, Eastern diamondback rattlesnake, and Southern Pacific rattlesnake, cause clinically relevant hypofibrinogenemia via thrombin-like activity in their venom. It has been demonstrated that iron (Fe) and carbon monoxide (CO) change the ultrastructure of plasma thrombi and improve coagulation kinetics. Thus, the present investigation sought to determine if pretreatment of plasma with Fe and CO could attenuate venom-mediated catalysis of fibrinogen via thrombin-like activity. Human plasma was pretreated with ferric chloride (0-10 µM) and CO-releasing molecule-2 (0-100 µM) prior to exposure to 2.5-10 µg/ml of venom obtained from the aforementioned three species of rattlesnake. Coagulation kinetics were determined with thrombelastography. All three snake venoms degraded plasmatic coagulation kinetics to a significant extent, especially diminishing the speed of clot growth and strength. Pretreatment of plasma with Fe and CO completely abrogated the effects of all three venoms on coagulation kinetics. Further in vitro investigation of other pit viper venoms that possess thrombin-like activity is indicated to see if there is significant conservation of venom enzymatic target recognition of specific amino acid sequences such that Fe and CO can reliably attenuate venom-mediated catalysis of fibrinogen. These data also serve as a rationale for future preclinical investigation.
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Coagulación Sanguínea/efectos de los fármacos , Monóxido de Carbono/farmacología , Cloruros/farmacología , Venenos de Crotálidos/toxicidad , Compuestos Férricos/farmacología , Compuestos Organometálicos/farmacología , Plasma/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Fibrinógeno/metabolismo , Humanos , Técnicas In Vitro , Plasma/química , Plasma/metabolismo , TromboelastografíaRESUMEN
The 15q13.3 microdeletion syndrome is caused by a 1.5-MB hemizygous microdeletion located on 15q13.3 affecting seven genes: FAN1; MTMR10; TRPM1; miR-211; KLF13; OTUD7A; and CHRNA7. The 15q13.3 microdeletion increases the risk of intellectual disability, epilepsy, autism spectrum disorder and schizophrenia, though the clinical profile varies considerably. Two mouse models of this syndrome, with hemizygous deletion of the orthologous region in the murine genome, have recently been shown to recapitulate a number of the behavioral and physiological deficits that characterize the human condition. Still, little is known of the underlying biological mechanisms. Eleven human cases with homozygous deletion of the 15q13.3 region have been reported, all with severe functional and physiological impairments. We therefore hypothesized that a 15q13.3 homozygous knockout would confer more pronounced behavioral and physiological deficits in mice than the 15q13.3 hemizygous deletion. Here we report the characterization of a 15q13.3 knockout mouse. We observed marked deficits including altered seizure susceptibility, autistic behavior-related phenotypes, and auditory sensory processing. Several of these deficits, albeit less pronounced, were also found in the 15q13.3 hemizygous littermates indicating a gene-dosage dependency. Our findings strongly indicate that studies of the hemi- and homozygous 15q13.3 mouse strains will facilitate understanding of the biological mechanisms of severe mental disorders.
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Trastorno Autístico/fisiopatología , Conducta Animal , Trastornos de los Cromosomas/fisiopatología , Modelos Animales de Enfermedad , Epilepsia/fisiopatología , Discapacidad Intelectual/fisiopatología , Ratones , Esquizofrenia/fisiopatología , Convulsiones/fisiopatología , Animales , Trastornos de la Percepción Auditiva/genética , Trastornos de la Percepción Auditiva/fisiopatología , Trastorno Autístico/genética , Trastorno Autístico/psicología , Deleción Cromosómica , Trastornos de los Cromosomas/genética , Trastornos de los Cromosomas/psicología , Cromosomas Humanos Par 15/genética , Condicionamiento Psicológico , Convulsivantes/toxicidad , Epilepsia/inducido químicamente , Epilepsia/genética , Miedo , Hemicigoto , Homocigoto , Discapacidad Intelectual/genética , Discapacidad Intelectual/psicología , Ratones Noqueados , Comportamiento de Nidificación , Pentilenotetrazol/toxicidad , Inhibición Prepulso , Reflejo de Sobresalto , Esquizofrenia/genética , Psicología del Esquizofrénico , Convulsiones/genética , Convulsiones/psicología , Conducta Social , Vocalización AnimalRESUMEN
The gene coding for the alpha, beta-interferon (alpha, beta-IFN) receptor is localized to chromosome 21. Cells from patients with Down's syndrome contain an extra chromosome 21, and thereby an expected 1.5-times increase in the number of genes located to this chromosome and in consequence a 1.5-times increase in cell surface alpha-IFN receptors. Actual measurements of these by competition binding experiments with human recombinant alpha-IFN on peripheral blood mononuclear cells (PBMC) from patients with Down's syndrome resulted in a mean of 1.69, which is in accordance to the theoretical 1.50, but slightly overestimated due to the calculation method. The increased gene dosage of the alpha-IFN receptor was quantitatively verified by Southern blot-hybridizations. Further characterization of alpha-IFN receptor binding showed insignificant differences in dissociation constants among patients and healthy individuals.
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Síndrome de Down/genética , Interferón-alfa/metabolismo , Monocitos/metabolismo , Receptores de Interferón/genética , Cromosomas Humanos Par 21 , Simulación por Computador , Expresión Génica , Humanos , Receptores de Interferón/metabolismoRESUMEN
The pancreatic beta-cell mass and function in C57BL/KsJ mice is markedly reduced the day after the last injection of five daily injections of a subdiabetogenic, 40 mg/kg, dose of streptozocin (STZ). In this study, we prepared an H-2 alloantiserum by injecting C57BL/6J mice (H-2b) with spleen lymphocytes from C57BL/KsJ (H-2d) mice. The alloantiserum given on five consecutive days, 5 h before each injection of STZ, did not prevent the initial beta-cytotoxic effect of STZ detected by perfusion of the pancreas and subsequent morphometric analysis of in situ dithizone-perfused pancreas. However, 12 days after the first injection of STZ, total insulin release in response to D-glucose, total pancreatic insulin, and pancreatic glucagon was greater in the alloantiserum-treated mice compared with controls receiving normal mouse serum. It is concluded that an H-2 alloantiserum may protect the function and amounts of beta-cells remaining after the initial five low-dose STZ injections.
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Diabetes Mellitus Experimental/terapia , Antígenos H-2/inmunología , Inmunización Pasiva , Islotes Pancreáticos/fisiopatología , Animales , Glucemia/análisis , Diabetes Mellitus Experimental/fisiopatología , Glucagón/sangre , Insulina/sangre , Insulina/metabolismo , Secreción de Insulina , Islotes Pancreáticos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Interferon-alpha (IFN-alpha) is important in the innate immune defense, particularly in viral infections. IFN-alpha induces 2',5'A synthetase, the products of which, 2',5'-oligoadenine nucleotides, activate mRNA degrading enzymes. IFN-alpha is the first detectable cytokine in the insulitis lesion seen in recent-onset IDDM, and insulin promoter directed expression of IFN-alpha in transgenic mice leads to development of IDDM. Here, we demonstrate that IFN-alpha induces 2',5'A synthetase activity only in insulin-producing betaTC3 cells and in isolated single rat beta-cells but not in alphaTC3 cells or in isolated rat non-beta-cells. The increased responsiveness of beta-cells but not non-beta-cells to IFN-alpha with the ensuing activation of the mRNA-degrading 2',5'A synthetase system suggests why only the beta-cells are destroyed in the diabetogenic process.
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2',5'-Oligoadenilato Sintetasa/biosíntesis , Insulina/biosíntesis , Interferón-alfa/farmacología , Islotes Pancreáticos/fisiología , Animales , Línea Celular , Células Cultivadas , Diabetes Mellitus Tipo 1/inmunología , Inducción Enzimática , Expresión Génica , Insulina/genética , Interferón-alfa/biosíntesis , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/inmunología , Cinética , Masculino , Ratones , Ratones Transgénicos , Poli I-C/farmacología , Regiones Promotoras Genéticas , ARN Bicatenario/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas LewRESUMEN
Streptozotocin (SZ) given in five low doses causes diabetes and an associated lymphocytic infiltration of the pancreatic islets. Using C57BL/KsJ-mice, we demonstrate a reduction in islet number (--38%) and volume (--64%) within 1 day following the last injection of SZ. A substantial fall of insulin secretory capacity (--84%) in the in vitro perfused pancreas matches the reduction in islet cell volume. The parameters of decreased islet function seem to precede the peak of lymphocytic infiltration, occurring 3 days after the last dose of SZ. These functional changes are readily demonstrable before a rise in fasting blood glucose, but they seem to be reflected more readily by a rise in nonfasting blood glucose levels. With development of overt diabetes, as measured by elevated fasting and nonfasting glucose levels, the measures of islet volume and function are reduced to levels only 1--2% of those found in control mice. Taken together, these observations reflect a rapid, islet-toxic effect of SZ that substantially decreases insulin secretory capacity. When islet function falls more than 90%, blood glucose levels begin to reflect the pathophysiologic process. In many aspects, the low-dose SZ model of diabetes parallels the development of diabetes in man. If so, measures other than blood sugar must be developed to identify at an early stage processes reducing islet volume and function.
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Diabetes Mellitus Experimental/fisiopatología , Hiperglucemia/inducido químicamente , Islotes Pancreáticos/fisiopatología , Estreptozocina/farmacología , Animales , Glucemia/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/patología , Cinética , Masculino , RatonesRESUMEN
Basal and yellow fever vaccination-induced 2',5'-oligoadenylate synthetase (2',5'A) activity was determined in blood mononuclear cells (peripheral blood lymphocytes [PBLs]) from insulin-dependent diabetes mellitus (IDDM) and matched control subjects. The live attenuated yellow fever vaccine represented a primary stimulus in all subjects. First, basal 2',5'A activity increased severalfold in response to yellow fever vaccination. In IDDM subjects, this increase was significantly lower (P = .025). Second, the 2',5'A activity increased proportionately to the higher basal 2',5'A activity in IDDM subjects. In control subjects, the increase in 2',5'A activity was not dependent on the basal activity. There was no relationship between basal or stimulated 2',5'A activity and age, sex, duration of IDDM, age at onset of IDDM, metabolic control, or HLA-DQ beta-chain gene polymorphism. There is a direct relationship between 2',5'A activity and latent viral infections associated with the presence of double-stranded RNA and with cellular interferons (IFNs) formed in response to viral infections. The higher basal 2',5'A activity (P = .05) in relation to the stimulated activity may therefore signify a latent infection or the presence of double-stranded RNA in PBLs of IDDM subjects. In vitro stimulation of PBLs showed increased IFN sensitivity in IDDM subjects. Analysis of 2',5'A activity is proposed to be a sensitive measure of the activation of the IFN system and the level of latent infectivity.
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2',5'-Oligoadenilato Sintetasa/biosíntesis , Diabetes Mellitus Tipo 1/inmunología , Linfocitos/enzimología , Vacunas Virales/administración & dosificación , Virus de la Fiebre Amarilla/inmunología , 2',5'-Oligoadenilato Sintetasa/genética , Adulto , Anticuerpos Antivirales/análisis , Proteína C-Reactiva/análisis , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/enzimología , Inducción Enzimática , Femenino , Hemoglobina Glucada/análisis , Humanos , Inmunoglobulinas/análisis , Interferón Tipo I/farmacología , Cinética , Recuento de Leucocitos , Linfocitos/inmunología , Masculino , Pruebas de Neutralización , Polimorfismo de Longitud del Fragmento de Restricción , Valores de Referencia , Análisis de RegresiónRESUMEN
The natural history of diabetic neuropathy and its risk factors are not well understood, apart from the recognition that prevalence increases with duration and, in many studies, degree of glycemia. The role of potential risk factors was therefore evaluated in a cross-sectional analysis from the baseline examination of the Pittsburgh Epidemiology of Diabetes Complications Study. We present results from the first 400 subjects seen at baseline examination. Neuropathy was determined by a trained internist with a standardized examination and was defined as the presence of at least two of three criteria: abnormal sensory or motor signs, symptoms consistent with neuropathy, and decreased tendon reflexes. The prevalence of neuropathy in this cohort was 34% (18%, 18-29 yr old, 58% greater than or equal to 30 yr old) with no difference by sex. By focusing on subjects greater than or equal to 18 yr old, all significant univariate variables (e.g., duration, glycosylated hemoglobin [HbA1]) were analyzed in 3 multiple logistic regression models: all subjects greater than or equal to 18 yr old and separating the same subjects into two groups based on age (18-29 and greater than or equal to 30 yr). Duration, HbA1, smoking status, and high-density lipoprotein cholesterol were found to be associated with neuropathy in the models for the greater than or equal to 18-yr-old group and the greater than or equal to 30-yr-old group. In the 18- to 29-yr-old group, duration, HbA1, and hypertension status were found to be significantly associated with neuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)