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1.
J Med Entomol ; 59(3): 976-986, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35134194

RESUMO

Ixodes pacificus Cooley & Kohls is the primary vector of Lyme disease spirochetes to humans in the western United States. Although not native to Alaska, this tick species has recently been found on domestic animals in the state. Ixodes pacificus has a known native range within the western contiguous United States and southwest Canada; therefore, it is not clear if introduced individuals can successfully survive and reproduce in the high-latitude climate of Alaska. To identify areas of suitable habitat within Alaska for I. pacificus, we used model parameters from two existing sets of ensemble habitat distribution models calibrated in the contiguous United States. To match the model input covariates, we calculated climatic and land cover covariates for the present (1980-2014) and future (2070-2100) climatologies in Alaska. The present-day habitat suitability maps suggest that the climate and land cover in Southeast Alaska and portions of Southcentral Alaska could support the establishment of I. pacificus populations. Future forecasts suggest an increase in suitable habitat with considerable uncertainty for many areas of the state. Repeated introductions of this non-native tick to Alaska increase the likelihood that resident populations could become established.


Assuntos
Ixodes , Ixodidae , Doença de Lyme , Alaska , Animais , Ecossistema , Incerteza , Estados Unidos
2.
Ecol Appl ; 30(4): e02081, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31971646

RESUMO

The ability to quantify spatial patterns and detect change in terrestrial vegetation across large landscapes depends on linking ground-based measurements of vegetation to remotely sensed data. Unlike non-overlapping categorical vegetation types (i.e., typical vegetation and land cover maps), species-level gradients of foliar cover are consistent with the ecological theories of individualistic response of species and niche space. We collected foliar cover data for vascular plant, bryophyte, and lichen species and 17 environmental variables in the Arctic Coastal Plain and Brooks Foothills of Alaska from 2012 to 2017. We integrated these data into a standardized database with 13 additional vegetation survey and monitoring data sets in northern Alaska collected from 1998 to 2017. To map the patterns of foliar cover for six dominant and widespread vascular plant species in arctic Alaska, we statistically associated ground-based measurements of species distribution and abundance to environmental and multi-season spectral covariates using a Bayesian statistical learning approach. For five of the six modeled species, our models predicted 36% to 65% of the observed species-level variation in foliar cover. Overall, our continuous foliar cover maps predicted more of the observed spatial heterogeneity in species distribution and abundance than an existing categorical vegetation map. Mapping continuous foliar cover at the species level also revealed ecological patterns obscured by aggregation in existing plant functional type approaches. Species-level analysis of vegetation patterns enables quantifying and monitoring landscape-level changes in species, vegetation communities, and wildlife habitat independently of subjective categorical vegetation types and facilitates integrating spatial patterns across multiple ecological scales. The novel species-level foliar cover mapping approach described here provides spatial information about the functional role of plant species in vegetation communities and wildlife habitat that are not available in categorical vegetation maps or quantitative maps of broadly defined vegetation aggregates.


Assuntos
Ecossistema , Plantas , Alaska , Regiões Árticas , Teorema de Bayes
3.
J Clin Densitom ; 20(2): 216-225, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-26781430

RESUMO

Conventional quantitative computed tomography (QCT) uses a phantom scanned simultaneously with the anatomical region of interest. A newly developed method called asynchronous QCT does not require a phantom to be present during the patient scan. This allows the inclusion of computer tomography scans performed without any calibration standard in a different clinical context than bone densitometry, for example, in a screening context. In the present study, the asynchronous and the conventional quantitative computed tomographies were compared. Specifically, short-term precision, a phantom-induced bias, methodical equivalence of the asynchronous and the conventional methods, and interobserver variability were investigated. Ten phantom scans served for investigation of short-term precision. A prospective dataset of 43 study participants (44-80 years, mean 63.8 ± 8.6 years) was acquired over 3 clinical sites. Trabecular regions of the spine as well as cortical and trabecular regions of the hip (femoral neck, trochanter, intertrochanter, and shaft) were analyzed with respect to the presence or absence of a phantom and with regard to the synchronous and asynchronous calibration methods. Regarding precision, all variations of the mean areal and volumetric densities were lower for the asynchronous method than for the conventional method. The presence of the phantom resulted in a bias of 2.3 mg/cm3, and the choice of the asynchronously or synchronously calibrated analysis resulted in a bias of 3.7 mg/cm3 at the spine. Both were statistically, but not clinically, significant. The total hip was statistically, but not clinically, significantly different by 0.008 g/cm2. The bone density values between the 2 techniques correlated highly with one another at all regions investigated. Interobserver variability between 2 trained observers showed a difference of 0.2 mg/cm3 (spine) and differences less or equal to 0.009 g/cm2 (hip), which again was regarded as clinically nonsignificant. In summary, the asynchronously calibrated QCT provides results comparable to the established synchronously calibrated QCT.


Assuntos
Densidade Óssea , Calibragem , Colo do Fêmur/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Osso Esponjoso/diagnóstico por imagem , Diáfises/diagnóstico por imagem , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Imagens de Fantasmas , Estudos Prospectivos
4.
Osteoporos Int ; 23(8): 2151-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22143491

RESUMO

UNLABELLED: In vivo hr-pQCT precision was determined in 42 postmenopausal women using double baseline measurements from a multicenter trial of odanacatib. Errors, e.g., at the radius below 1.3% for BMD and below 6.3% for trabecular structure, were comparable to single-center results. Motion artifacts remain a challenge, particularly at the forearm. INTRODUCTION: The short-term in vivo precision of BMD, trabecular bone structure, cortical thickness and porosity of the forearm and tibia was measured by hr-pQCT. Also the effect of image quality on precision was evaluated. METHODS: In 42 postmenopausal women (age 64.4 ± 6.8 years) out of 214 subjects enrolled in a multi center advanced imaging phase III study of odanacatib (DXA spine or hip T-scores between -1.5 and -3.5), double baseline hr-pQCT (XtremeCT) measurements with repositioning were performed. The standard ultradistal location and a second, more proximally located VOI were measured at the radius and tibia to better assess cortical thickness and porosity. Image analysis and quality grading (grades: perfect, slight artifacts, pronounced artifacts, unacceptable) were performed centrally. RESULTS: At the radius RMS%CV values varied from 0.7% to 1.3% for BMD and BV/TV and from 5.6% to 6.3% for Tb.Sp, Tb.Th, Tb.N, and cortical porosity. Numerically at the tibia, precision errors were approx. 0.5% lower for BMD and 1% to 2% lower for structural parameters although most differences were insignificant. In the radius but not in the tibia, precision errors for cortical thickness were smaller at the distal compared to the ultradistal location (1% versus 2%). CONCLUSIONS: BMD precision errors were lower than those for trabecular architecture and cortical porosity. Motion artifacts remain a challenge, particularly at the forearm. Quality grading remains subjective, and more objective evaluation methods are needed. Precision in the context of a multicenter clinical trial, with centralized training and scan analysis, was comparable to single-center results previously reported.


Assuntos
Densidade Óssea/fisiologia , Osteoporose Pós-Menopausa/diagnóstico por imagem , Rádio (Anatomia)/diagnóstico por imagem , Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Pessoa de Meia-Idade , Pós-Menopausa
5.
Am J Physiol Endocrinol Metab ; 293(1): E385-95, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17456640

RESUMO

Information on the pathophysiology of glucocorticoid-induced osteoporosis (GIO) is limited, since its clinical picture often reflects a combined effect of glucocorticoids (GC) and the treated systemic disease (i.e., inflammation and immobility). In 50 healthy adult (30-mo-old) primiparous Göttingen minipigs, we studied the short-term (8 mo, n = 30) and long-term (15 mo, n = 10) effect of GC on bone and mineral metabolism longitudinally and cross-sectionally compared with a control group (n = 10). All animals on GC treatment received prednisolone orally at a dose of 1.0 mg x kg body wt(-1) x day(-1) for 8 wk and thereafter at 0.5 mg/kg body wt(-1) x day(-1). In the short term, GC reduced bone mineral density (BMD) at the lumbar spine by -47.5 +/- 5.1 mg/cm(3) from baseline (P < 0.001), which was greater (P < 0.05) than the loss [not significant (NS)] in the control group of -11.8 +/- 12.6 mg/cm(3). Calcium absorption decreased from baseline by -2,488 +/- 688 mg/7 days (P < 0.001) compared with -1,380 +/- 1,297 mg/7 days (NS) in the control group. Plasma bone alkaline phosphatase (BAP) decreased from baseline by -17.8 +/- 2.2 U/l (P < 0.000), which was significantly different (P < 0.05) from the value of the control group of -1.43 +/- 4.8 U/l. In the long term, the loss of BMD became more pronounced and bone mineral content (BMC), trabecular thickness, mechanical stability, calcium absorption, 25-hydroxyvitamin D(3), 1,25-dihydroxyvitamin D(3), and parathyroid hormone tended to be lower compared with the control group. There was a negative association between the cumulative dose of GC and BMD, which was associated with impaired osteoblastogenesis. In conclusion, the main outcomes after GC treatment are comparable to symptoms of GC-induced osteoporosis in human subjects. Thus the adult Göttingen miniature pig appears to be a valuable animal model for GC-induced osteoporosis.


Assuntos
Densidade Óssea/efeitos dos fármacos , Glucocorticoides , Minerais/metabolismo , Osteoporose/induzido quimicamente , Paridade , Animais , Peso Corporal/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiologia , Cálcio/sangue , Cálcio/urina , Força Compressiva/efeitos dos fármacos , Modelos Animais de Doenças , Feminino , Osteoporose/metabolismo , Fósforo/sangue , Fósforo/urina , Gravidez , Suínos , Fatores de Tempo
6.
Bone ; 40(3): 645-55, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17174621

RESUMO

The Göttingen minipig is one of the few large animal models that show glucocorticoid (GC)-induced bone loss. We investigated whether GC-induced loss of bone mineral density (BMD) and bone strength in minipigs can be recovered by treatment with the bisphosphonate ibandronate (IBN). 40 primiparous sows were allocated to 4 groups when they were 30 months old: GC treatment for 8 months (GC8), for 15 months (GC15), GC treatment for 15 months plus IBN treatment for months 8-15 (GC&IBN), and a control group without GC treatment. Prednisolone was given at a daily oral dose of 1 mg/kg body weight for 8 weeks and thereafter 0.5 mg/kg body weight. IBN was administered intramuscularly and intermittently with an integral dose of 2.0 mg/kg body weight. BMD of the lumbar spine (L1-3) was assessed in vivo by Quantitative Computed Tomography (QCT) at months 0, 8, and 15. Blood and urine samples were obtained every 2-3 months. After sacrificing the animals lumbar vertebrae L4 were tested mechanically (Young's modulus and ultimate stress). Histomorphometry was performed on L2 and mineral content determined in ashed specimens of T12 and L4. In the GC&IBN group, the GC associated losses in BMD of -10.5%+/-1.9% (mean+/-standard error of the mean, p<0.001) during the first 8 months were more than recovered during the following 7 months of IBN treatment (+14.8%+/-1.2%, p<0.0001). This increase was significantly larger (p<0.0001) than the insignificant +2.1%+/-1.2% change in group GC15. At month 15, the difference between groups GC&IBN and GC15 was 22% (p<0.01) for BMD, 48% (p<0.05) for Young's modulus, and 31% (p<0.14) for ultimate stress; bone-specific alkaline phosphatase showed trends to lower values (p<0.2) while deoxypyridinoline was comparable. This minipig study demonstrates that GC-induced impairment of bone strength can be effectively and consistently treated by IBN. GC&IBN associated alterations in BMD and bone turnover markers can be monitored in vivo using QCT of the spine and by biochemical analyses, reflecting the changes in bone strength.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Difosfonatos/uso terapêutico , Glucocorticoides/efeitos adversos , Osteoporose/induzido quimicamente , Osteoporose/prevenção & controle , Absorciometria de Fóton , Fosfatase Alcalina/sangue , Fosfatase Alcalina/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Feminino , Ácido Ibandrônico , Vértebras Lombares/efeitos dos fármacos , Suínos , Porco Miniatura
7.
J Clin Microbiol ; 37(3): 807-11, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9986861

RESUMO

The Sphaeropsidales, coelomycetous fungi producing asexual conidia within enclosed conidiomata (pycnidia), are saprobic on numerous vascular plants. Despite their ubiquitous nature, only a limited number of genera have been documented as causing human disease. We report what we believe to be the first human case of osteomyelitis due to a Phomopsis species in a chronically immunosuppressed female. The patient developed a subcutaneous abscess on the distal phalanx of the right fourth finger complicated by osteomyelitis. Operative specimens revealed fungal hyphae and a pure culture of mould. The patient was treated with a 6-month course of itraconazole. At 16 months of follow-up, she remained free of recurrence. Phomopsis species differ from the similar, more frequently reported Phoma species by having immersed, thick-walled, multiloculate conidiomata and by the production of alpha (short, ellipsoidal) and beta (long, filamentous) conidia.


Assuntos
Ascomicetos , Terapia de Imunossupressão/efeitos adversos , Micoses/complicações , Osteomielite/microbiologia , Artrite Reumatoide/tratamento farmacológico , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Feminino , Humanos , Imunossupressores/efeitos adversos , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Micoses/diagnóstico , Osteomielite/diagnóstico por imagem , Osteomielite/patologia , Prednisona/efeitos adversos , Radiografia
8.
J Hand Ther ; 6(3): 190-3, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8401799

RESUMO

Studies have shown that functional activities involving pronation and supination, such as turning a doorknob or a screwdriver, involve wrist positions of extension and/or ulnar deviation. Previous studies of isometric forearm pronation and supination strength have utilized a neutral wrist position, resulting in a possible underestimation of true functional strength. Twenty healthy subjects between the ages of 24 and 45 years were assessed for isometric pronation and supination strength using cylinder, screwdriver, and doorknob handle adaptations. Maximal strength in both pronation and supination was observed with the use of the doorknob handle. Although pronation strength was exceeded by supination strength within all three handle adaptations, the difference was statistically significant for the screwdriver and doorknob handles. The results suggest that in clinical and research-oriented testing of maximal forearm rotation strength, further consideration must be given to the terminal grip device and positioning of the wrist.


Assuntos
Traumatismos do Braço/fisiopatologia , Pronação/fisiologia , Supinação/fisiologia , Adulto , Fenômenos Biomecânicos , Ergometria/instrumentação , Feminino , Humanos , Contração Isométrica , Masculino , Punho
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