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Clinical characterization of a hypersensitivity mixed bacterial and fungal dermatitis in a translational model of porcine NASH. Front Cell Infect Microbiol 2024; 13:1277045. [PMID: 38327680 PMCID: PMC10847572 DOI: 10.3389/fcimb.2023.1277045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Accepted: 12/28/2023] [Indexed: 02/09/2024] Open
Abstract
Introduction The development of animal models of chronic liver disease via diet modification is a promising avenue for translational research but can lead to unexpected side effects that impact model adoption. While these side effects are well characterized in rodent models of nonalcoholic steatohepatitis (NASH), limited knowledge of these effects exists for novel porcine models of NASH. To close this gap, the present study investigates the side effects of diet-based NASH induction in pigs, with a systematic analysis of the pathologic mechanisms underlying dermatitis development and evaluation of treatment approaches. Method Twelve pigs (10 large domestic pigs, 2 Goettingen minipigs) were fed a methionine- and choline-deficient, high-fat diet for 8 weeks to induce NASH. A retrospective review of each animal's clinical record was performed to identify the side effects of the diet. Following the identification of diet-associated dermatitis, severity was judged by using a novel gradation system that characterized the individual lesions and body regions resulting in a cumulative evaluation. In addition to this clinical assessment, the etiology of the dermatitis was investigated via histopathologic and microbiologic testing. Furthermore, the success of prophylactic and therapeutic treatment approaches was evaluated by considering dermatitis development and clinical course. Results All study animals demonstrated unexpected side effects of the methionine- and choline-deficient, high fat diet. In addition to marked dermatitis, study pigs showed impaired weight gain and developed steatorrhea and anemia. Based on the skin gradation system, five animals developed severe dermatitis, four animals moderate dermatitis, and three animals mild diet-associated dermatitis. Histological and microbiological evaluation of the affected skin showed signs of a hypersensitivity reaction with secondary infection by bacteria and fungi. The analysis showed that preemptive bathing extended the lesion-free duration by nearly 20 days. Furthermore, bathing in combination with a targeted antibiotic treatment represented a helpful treatment approach for diet-associated dermatitis. Conclusion The provision of a methionine- and choline-deficient, high fat diet represents an effective approach for inducing NASH liver disease in pigs but predisposes study animals to multiple side effects. These side effects are universal to animals on study but can be adequately managed and do not represent a significant limitation of this model.
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Development of a Corneal and Eye Protection Strategy in Domestic Swine. Comp Med 2023; 73:373-377. [PMID: 38087405 PMCID: PMC10702166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/12/2022] [Accepted: 06/20/2023] [Indexed: 12/18/2023]
Abstract
Large animal models are essential to research in facial paralysis, face transplant, craniofacial surgery, and ophthalmology. Pigs are a well-studied species with high similarity to human anatomy and physiology for these research areas. However, in contrast to cats and dogs protecting the cornea and eye is difficult in swine due to the inability to use an Elizabethan collar (E-collar) and the complexity of placing and maintaining a temporary tarsorrhaphy for corneal protection due to the strength of the pig levator muscle. This study presents an effective method to provide corneal and eye protection in the domestic swine for at least 50 d. Furthermore, protection of the eye and face is achieved through the innovative use of a modified ophthalmologic face shield. The findings from this study will advance large animal research in these fields, enabling innovation in surgery and tissue engineering in areas of both craniofacial and ophthalmologic research.
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Revisit and Perfect the Policy. Lab Anim (NY) 2022; 51:279. [PMID: 36284241 DOI: 10.1038/s41684-022-01075-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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A typology of North Sea oil and gas platforms. Sci Rep 2022; 12:8079. [PMID: 35577866 PMCID: PMC9109754 DOI: 10.1038/s41598-022-11975-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/22/2022] [Indexed: 11/29/2022] Open
Abstract
Since the commercial exploitation of marine oil and gas reserves began in the middle of the twentieth century, extensive networks of offshore infrastructure have been installed globally. Many of the structures are now nearing the end of their operational lives and will soon require decommissioning, generating renewed interest in their environmental impacts and in the ecological consequences of their removal. However, such work requires selection of a subsample of assets for surveying; censuses of the entire ‘population’ in any given jurisdiction are practically impossible due to their sheer number. It is important, therefore, that the selected sample is sufficiently representative of the population to draw generalized conclusions. Here, a formal clustering methodology, partitioning around medoids, was used to produce a typology of surface-piercing oil and gas platforms in the North Sea. The variables used for clustering were hydrocarbon product, operational state, platform design and material, and substructure weight. Assessing intra-cluster variability identified 13 clusters as the optimum number. The most important distinguishing variable was platform type, isolating floating platforms first, then concrete gravity-based and then fixed steel. Following clustering, a geographic trend was evident, with oil production more prevalent in the north and gas in the south. The typology allows a representative subset of North Sea oil and gas platforms to be selected when designing a survey, or an assessment of the representativeness of a previously selected subset of platforms. This will facilitate the efficient use of the limited funding available for such studies.
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Association of glucose metabolism and blood pressure during pregnancy with subsequent maternal blood pressure. J Hum Hypertens 2022; 36:61-68. [PMID: 33536549 PMCID: PMC8329103 DOI: 10.1038/s41371-020-00468-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/09/2020] [Accepted: 12/07/2020] [Indexed: 01/31/2023]
Abstract
The goal of this study was to examine associations of measures of maternal glucose metabolism and blood pressure during pregnancy with blood pressure at follow-up in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort. The HAPO Follow-Up Study included 4747 women who had a 75-g oral glucose tolerance test (OGTT) at ~28 weeks' gestation. Of these, 4572 women who did not have chronic hypertension during their pregnancy or other excluding factors, had blood pressure evaluation 10-14 years after the birth of their HAPO child. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), and hypertension (SBP ≥ 140 and/or DBP ≥ 90 or treatment for hypertension) at follow-up. Blood pressure during pregnancy was associated with all blood pressure outcomes at follow-up independent of glucose and insulin sensitivity during pregnancy. The sum of glucose z-scores was associated with blood pressure outcomes at follow-up but associations were attenuated in models that included pregnancy blood pressure measures. Associations with SBP were significant in adjusted models, while associations with DBP and hypertension were not. Insulin sensitivity during pregnancy was associated with all blood pressure outcomes at follow-up, and although attenuated after adjustments, remained statistically significant (hypertension OR 0.79, 95%CI 0.68-0.92; SBP beta -0.91, 95% CI -1.34 to -0.49; DBP beta -0.50, 95% CI -0.81 to -0.19). In conclusion, maternal glucose values at the pregnancy OGTT were not independently associated with maternal blood pressure outcomes 10-14 years postpartum; however, insulin sensitivity during pregnancy was associated independently of blood pressure, BMI, and other covariates measured during pregnancy.
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Socio-economic, demographic, and clinical correlates of poor glycaemic control within insulin regimens among children with Type 1 diabetes: the SEARCH for Diabetes in Youth Study. Diabet Med 2019; 36:1028-1036. [PMID: 31050009 PMCID: PMC6635011 DOI: 10.1111/dme.13983] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/01/2019] [Indexed: 12/31/2022]
Abstract
AIM To examine the distribution and association of sociodemographic, adherence, and barriers-to-care factors in relation to glycaemic control within insulin regimens in US children with Type 1 diabetes in the SEARCH for Diabetes in Youth Study. METHODS Self- or parent-reported data from 1095 children with Type 1 diabetes aged 10-17 years were collected on insulin regimen, sociodemographics, diabetes self-management, diabetes-related family conflict and barriers to care. Multivariable logistic regression analysis identified poor glycaemic control correlates within each insulin regimen. RESULTS Participants included 694 children on insulin pump therapy, 188 receiving basal-bolus injections, and 213 on a mixed insulin regimen. Of these, 28.5%, 45.2% and 51.2%, respectively, had poor glycaemic control [HbA1c ≥ 80 mmol/mol (9.5%)]. Family conflict between parent and child regarding diabetes management was the only factor significantly associated with poor glycaemic control in all insulin regimens (insulin pump, P≤ 0.0001; basal-bolus injections, P=0.0002; mixed insulin regimen, P=0.0103). For children on insulin pump, poor control was significantly associated with non-white race (P=0.0008), living in multiple households (P=0.0331), having Medicaid insurance (P=0.0090), and decreased insulin adherence (P<0.0001). For children on a mixed insulin regimen, living in multiple households (P=0.0256) and not spending enough time with healthcare provider (P=0.0058) correlated with poor control. CONCLUSIONS A high percentage of US children with Type 1 diabetes had poor glycaemic control, especially those not using an insulin pump. Early identification of children with risk factors associated with poor glycaemic control within insulin regimens and addressing diabetes-related family conflict may allow interventions to improve diabetes management.
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Transfer from paediatric to adult care for young adults with Type 2 diabetes: the SEARCH for Diabetes in Youth Study. Diabet Med 2018; 35:504-512. [PMID: 29377258 PMCID: PMC6130201 DOI: 10.1111/dme.13589] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/22/2018] [Indexed: 12/17/2022]
Abstract
AIM To describe factors associated with transfer from paediatric to adult care and poor glycaemic control among young adults with Type 2 diabetes, using the SEARCH for Diabetes in Youth study. METHODS Young adults with Type 2 diabetes were included if they had a baseline SEARCH visit while in paediatric care at < 18 years and ≥ 1 follow-up SEARCH visit thereafter at 18-25 years. At each visit, HbA1c , BMI, self-reported demographic and healthcare provider data were collected. Associations of demographic factors with transfer of care and poor glycaemic control (HbA1c ≥ 75 mmol/mol; 9.0%) were explored with multivariable logistic regression. RESULTS 182 young adults with Type 2 diabetes (36% male, 75% minority, 87% with obesity) were included. Most (n = 102, 56%) reported transfer to adult care at follow-up; a substantial proportion (n = 28, 15%) reported no care and 29% did not transfer. Duration of diabetes [odds ratio (OR) 1.4, 95% confidence interval (95% CI) 1.1, 1.8] and age at diagnosis (OR 1.8, 95% CI 1.4, 2.4) predicted leaving paediatric care. Transfer to adult or no care was associated with a higher likelihood of poor glycaemic control at follow-up (adult: OR 4.5, 95% CI 1.8, 11.2; none: OR 4.6, 95% CI 1.4, 14.6), independent of sex, age, race/ethnicity or baseline HbA1c level. CONCLUSIONS Young adults with Type 2 diabetes exhibit worsening glycaemic control and loss to follow-up during the transfer from paediatric to adult care. Our study highlights the need for development of tailored clinical programmes and healthcare system policies to support the growing population of young adults with youth-onset Type 2 diabetes.
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Association between breastfeeding and insulin sensitivity among young people with Type 1 and Type 2 diabetes: the SEARCH Nutrition Ancillary Study. Diabet Med 2016; 33:1452-5. [PMID: 26972798 PMCID: PMC5018905 DOI: 10.1111/dme.13112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/08/2016] [Indexed: 11/28/2022]
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Abstract
We review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effect and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger's theorem, the Friedel sum rule, the Schrieffer-Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Noziéres exhaustion principle, Doniach's diagram, the Anderson lattice model, the Slave-Boson method, etc.
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Association of adherence to a Mediterranean diet with glycemic control and cardiovascular risk factors in youth with type I diabetes: the SEARCH Nutrition Ancillary Study. Eur J Clin Nutr 2016; 70:802-7. [PMID: 26908421 PMCID: PMC4935596 DOI: 10.1038/ejcn.2016.8] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Revised: 12/20/2015] [Accepted: 01/17/2016] [Indexed: 02/07/2023]
Abstract
Background/Objectives This study aimed to determine the association between a Mediterranean diet and glycemic control and other cardiovascular risk factors among youth with type 1 diabetes (T1D). Subjects/Methods Incident T1D cases aged <20 years at diagnosis between 2002 and 2005 were included. Participants were seen at baseline (N=793), 1-year (N=512) and 5-year follow-up visits (N=501). Mediterranean diet score was assessed using a modified KIDMED index (mKIDMED). Multivariate linear regression and longitudinal mixed model were applied to determine the association between mKIDMED score and log-HbA1c, lipids, blood pressure (BP), and obesity. Results In cross-sectional analyses using baseline data, for individuals with an HbA1c of 7.5%, a two-point higher mKIDMED score (one standard deviation) was associated with 0.15% lower HbA1c (P=0.02). A two-point higher mKIDMED score was associated with 4.0 mg/dL lower total cholesterol (TC) (P=0.006), 3.4 mg/dL lower low-density lipoprotein (LDL)-C (P=0.004), 3.9 mg/dL lower non-high-density lipoprotein (non-HDL)-C (P=0.004), and 0.07 lower LDL-C/HDL-C ratio (P=0.02). Using longitudinal data, a two-point increase in mKIDMED score was associated with 0.01% lower log-HbA1c (P=0.07), 1.8 mg/dL lower TC (P=0.05), 1.6 mg/dL lower LDL-C (P=0.03), and 1.8 mg/dL lower non-HDL-C (P=0.03) than would otherwise have been expected. HbA1c mediated about 20% of the association for lipids in both cross-sectional and longitudinal models. An unexpected positive association between mKIDMED score and systolic BP was found among non-Hispanic white youth in cross-sectional analyses (P=0.009). Mediterranean diet was not associated with obesity. Conclusions Mediterranean diet may improve glycemic control and cardiovascular health in T1D youth.
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Quantum critical fluctuations in the heavy fermion compound Ce(Ni0.935Pd0.065)₂Ge₂. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:015602. [PMID: 25469766 DOI: 10.1088/0953-8984/27/1/015602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Electric resistivity, specific heat, magnetic susceptibility, and inelastic neutron scattering experiments were performed on a single crystal of the heavy fermion compound Ce(Ni0.935Pd0.065)2Ge2 in order to study the spin fluctuations near an antiferromagnetic (AF) quantum critical point (QCP). The resistivity and the specific heat coefficient for T ⩽ 1 K exhibit the power law behavior expected for a 3D itinerant AF QCP (ρ(T) ∼ T(3/2) and γ(T) ∼ γ0 - bT(1/2)). However, for 2 ⩽ T ⩽ 10 K, the susceptibility and specific heat vary as log T and the resistivity varies linearly with temperature. Furthermore, despite the fact that the resistivity and specific heat exhibit the non-Fermi liquid behavior expected at a QCP, the correlation length, correlation time, and staggered susceptibility of the spin fluctuations remain finite at low temperature. We suggest that these deviations from the divergent behavior expected for a QCP may result from alloy disorder.
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Q-dependence of the spin fluctuations in the intermediate valence compound CePd3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:225602. [PMID: 24824417 DOI: 10.1088/0953-8984/26/22/225602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report inelastic neutron scattering experiments on a single crystal of the intermediate valence compound CePd3. At 300 K the magnetic scattering is quasielastic, with half-width Γ = 23 meV, and is independent of momentum transfer Q. At low temperature, the Q-averaged magnetic spectrum is inelastic, exhibiting a broad peak centered near Emax = 55 meV. These results, together with the temperature dependence of the susceptibility, 4f occupation number, and specific heat, can be fit by the Kondo/Anderson impurity model. The low temperature scattering near Emax, however, shows significant variations with Q, reflecting the coherence of the 4f lattice. The intensity is maximal at (1/2, 1/2, 0), intermediate at (1/2, 0, 0) and (0, 0, 0), and weak at (1/2, 1/2, 1/2). We discuss this Q-dependence in terms of current ideas about coherence in heavy fermion systems.
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Vitamin D in youth with Type 1 diabetes: prevalence of insufficiency and association with insulin resistance in the SEARCH Nutrition Ancillary Study. Diabet Med 2013; 30:1324-32. [PMID: 23909945 PMCID: PMC3822440 DOI: 10.1111/dme.12297] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/30/2013] [Indexed: 01/06/2023]
Abstract
AIMS To determine the prevalence of plasma vitamin D (25-dihydroxyvitamin D) insufficiency in individuals with Type 1 diabetes and to determine the cross-sectional and longitudinal associations of plasma vitamin D with insulin resistance. METHODS Participants from the SEARCH for Diabetes in Youth Study [n = 1426; mean age 11.2 years (sd 3.9)] had physician-diagnosed Type 1 diabetes [diabetes duration mean 10.2 months (sd 6.5)] with data available at baseline and follow-up (approximately 12 and 24 months after baseline). Insulin resistance was estimated using a validated equation. Cross-sectional and longitudinal multivariate logistic regression models were used to determine the association of plasma vitamin D with insulin resistance, adjusting for potential confounders. RESULTS Forty-nine per cent of individuals had plasma vitamin D < 50 nmol/l and 26% were insulin resistant. In cross-sectional multivariate analyses, participants who had higher plasma vitamin D (65 nmol/l) had lower odds of prevalent insulin resistance than participants with lower plasma vitamin D (25 nmol/l) (odds ratio 0.70, 95% CI 0.57-0.85). This association was attenuated after additional adjustment for BMI z-score, which could be a confounder or a mediator (odds ratio 0.81, 95% CI 0.64-1.03). In longitudinal multivariate analyses, individuals with higher plasma vitamin D at baseline had lower odds of incident insulin resistance, but this was not significant (odds ratio 0.85, 95% CI 0.63-1.14). CONCLUSIONS Vitamin D insufficiency is common in individuals with Type 1 diabetes and may increase risk for insulin resistance. Additional prospective studies are needed to determine the association between plasma vitamin D and insulin resistance, and to further examine the role of adiposity on this association.
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Abstract
AIMS The aim of this pilot study was to generate an initial estimate of the prevalence and correlates of diabetic retinopathy in a racially and ethnically diverse sample of youth with Type 1 and Type 2 diabetes mellitus. METHODS A pilot study was conducted among 222 individuals with Type 1 diabetes (79% non-Hispanic white, 21% other) and 43 with Type 2 diabetes (28% non-Hispanic white, 72% other), all of > 5 years duration (mean duration 6.8 years) who participated in the SEARCH for Diabetes in Youth study. Diabetic retinopathy was assessed using non-mydriatic retinal photography of both eyes. RESULTS The prevalence of diabetic retinopathy was 17% for Type 1 diabetes and 42% for Type 2 diabetes (odds ratio 1.50, 95% CI 0.58-3.88; P = 0.40 adjusted for age, duration, gender, race/ethnicity, parental education and HbA(1c). HbA(1c) was significantly higher among those with any diabetic retinopathy (adjusted mean 79 mmol/mol, 9.4%) vs. no diabetic retinopathy (adjusted mean 70 mmol/mol, 8.6%) (P = 0.015). LDL cholesterol was also significantly higher among those with any diabetic retinopathy (adjusted mean 107.2 mg/dl) compared with those without diabetic retinopathy (adjusted mean 97.9 mg/dl) (P = 0.04). CONCLUSIONS The prevalence of diabetic retinopathy in contemporary young individuals was substantial, particularly among minority youth and those with Type 2 diabetes. Further long-term study of diabetic retinopathy in youth is needed.
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Racial and ethnic disparities in diabetes risk after gestational diabetes mellitus. Diabetologia 2011; 54:3016-21. [PMID: 22016046 DOI: 10.1007/s00125-011-2330-2] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 09/09/2011] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS To investigate racial/ethnic disparities in diabetes risk after gestational diabetes mellitus (GDM). METHODS This is a retrospective cohort study of women enrolled in the Kaiser Permanente Southern California health plan from 1995 to 2009. GDM status was identified on the basis of plasma glucose levels during pregnancy. The incidence of diabetes after the first delivery complicated by GDM before 31 December 2009 (n = 12,998) was compared with the experience for women without GDM (n = 64,668) matched on maternal age at delivery, race/ethnicity and year of delivery (1:5 ratio). Matched Cox regression was used to compare the RRs of diabetes associated with GDM within and across racial/ethnic groups. RESULTS Compared with the women without GDM, the HRs (95% CI) of diabetes for women after GDM were 6.5 (5.2, 8.0) in non-Hispanic white, 7.7 (6.8, 8.7) in Hispanic, 9.9 (7.5, 13.1) in black and 6.3 (5.0, 7.9) in Asian/Pacific Islanders after adjustment for parity, maternal education, comorbidity and number of outpatient visits before the index pregnancy. The HR of diabetes for black women was significantly higher than that for non-Hispanic white women (p = 0.032). Further adjustment for prepregnancy BMI reduced the diabetes risk association with GDM for each racial/ethnic group, but did not explain the risk differences across groups. CONCLUSIONS/INTERPRETATIONS Racial/ethnic disparities exist in risk of diabetes after GDM. Black women with GDM had the highest risk of developing diabetes. This highlights the importance of developing an effective diabetes screening and prevention programme in women with GDM, particularly black women with GDM.
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Heavy fermion scaling: uranium versus cerium and ytterbium compounds. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:094210. [PMID: 21339563 DOI: 10.1088/0953-8984/23/9/094210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In an effort to explore the differences between rare-earth-based and uranium-based heavy fermion (HF) compounds that reflect the underlying difference between local 4f moments and itinerant 5f moments we analyze scaling laws that relate the low temperature neutron spectra of the primary ('Kondo-esque') spin fluctuation to the specific heat and susceptibility. While the scaling appears to work very well for the rare earth intermediate valence (IV) compounds, for a number of key uranium compounds the scaling laws fail badly. There are two main reasons for this failure. First, the presence of antiferromagnetic (AF) fluctuations, which contribute significantly to the specific heat, alters the scaling ratios. Second, the scaling laws require knowledge of the high temperature moment degeneracy, which is often undetermined for itinerant 5f electrons. By making plausible corrections for both effects, better scaling ratios are obtained for some uranium compounds. We point out that, while both the uranium HF compounds and the rare earth IV compounds have spin fluctuation characteristic energies of order 5-25 meV, they differ in that the AF fluctuations that are usually seen in the uranium compounds are never seen in the rare earth IV compounds. This suggests that the 5f itineracy increases the f-f exchange relative to the rare earth case.
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Association testing of TCF7L2 polymorphisms with type 2 diabetes in multi-ethnic youth. Diabetologia 2011; 54:535-9. [PMID: 21109996 PMCID: PMC3766323 DOI: 10.1007/s00125-010-1982-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 10/25/2010] [Indexed: 10/18/2022]
Abstract
AIM/HYPOTHESIS Common variants in the transcription factor 7-like 2 (TCF7L2) gene have been associated with type 2 diabetes in adults. However, it is not known whether TCF7L2 variation increases the risk of early onset type 2 diabetes. Using a case-control design, we examined whether the reported variants [rs12255372 (T/G) and rs7903146 (T/C)] are associated with type 2 diabetes in SEARCH for Diabetes in Youth study participants. METHODS Variants were genotyped in 694 non-Hispanic white (NHW) youth (86 cases, mean age 15.5 years, mean BMI 34.8; and 608 controls, mean age 14.4 years, mean BMI 22.3) and 545 African-American (AA) youth (154 cases, mean age 15.9, mean BMI 37; and 391 controls, mean age 14.8, mean BMI 23.8). Logistic regression adjusted for age, sex, BMI and West African ancestry. RESULTS The association of the risk T allele with case/control status was different in AA and NHW youth (p = 0.025). Among AA youth, each copy of the T allele (rs7903146) was associated with a 1.97-fold (1.37, 2.82) increased odds for type 2 diabetes (p < 0.0001), after adjustment for age, sex, BMI and African ancestry. No significant association was detected in NHW youth (adjusted OR, 1.14; 0.73, 1.79). CONCLUSION/INTERPRETATION TCF7L2 variation is associated with an increased risk of early-onset type 2 diabetes among AA youth, and the association appears to be stronger in AA than NHW youth. This suggests potential different contributions of genetic and environmental factors to early-onset type 2 diabetes by race.
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Transition from heavy-fermion to mixed-valence behavior in Ce(1-x)Y(x)Al3: a quantitative comparison with the anderson impurity model. PHYSICAL REVIEW LETTERS 2010; 104:176402. [PMID: 20482120 DOI: 10.1103/physrevlett.104.176402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Indexed: 05/29/2023]
Abstract
We present a neutron scattering investigation of Ce1-xYxAl3 as a function of chemical pressure, which induces a transition from heavy-fermion behavior in CeAl3 (T{K}=5 K) to a mixed-valence state at x=0.5 (T{K}=150 K). The crossover can be modeled accurately on an absolute intensity scale by an increase in the k-f hybridization, V{kf}, within the Anderson impurity model. Surprisingly, the principal effect of the increasing V{kf} is not to broaden the low-energy components of the dynamic magnetic susceptibility but to transfer spectral weight to high energy.
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Abstract
PURPOSE To examine the course of development of vascular disorders in the Royal College of Surgeons (RCS) rat and how these may lead to retinal ganglion cell loss. METHODS Whole-mount retinae from RCS rats were first stained for neurofilament protein and then for NADPH-diaphorase staining. A separate group of RCS rats was injected with Type II Peroxidase and the retinae were subsequently processed for peroxidase histochemistry. RESULTS The first changes in the deep vascular plexus occur as the photoreceptor layer is lost and it comes into close proximity to the retinal pigment epithelial (RPE) cell layer. RPE cells migrate onto retinal vessels, and at such locations vascular complex develop. These are first found ventral to the optic nerve head and then gradually progress over most of the retina. The inner retinal vessels that supply the complexes cross the optic nerve fiber layer and appear to be under tension. They ligate axons, which leads to retinal ganglion cell loss. CONCLUSIONS These observations show vascular changes can have secondary repercussions for neurons distant from the primary lesion.
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Abstract
Recent advances in stem cell biology have led to the exploration of stem cell-based therapies to treat a wide range of human diseases. In the ophthalmic field, much hope has been placed on the potential use of these cells to restore sight, particularly in those conditions in which other established treatments have failed and in which visual function has been irreversibly damaged by disease or injury. At present, there are many limitations for the immediate use of embryonic stem cells to treat ocular disease, and as more evidence emerges that adult stem cells are present in the adult human eye, it is clear that these cells may have advantages to develop into feasible therapeutic treatments without the problems associated with embryonic research and immune rejection. Here we discuss the current prospects for the application of various adult ocular stem cells to human therapies for restoration of vision.
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Changes in quality of life over the first year after stroke: findings from the Sunnybrook Stroke Study. J Stroke Cerebrovasc Dis 2007; 9:121-7. [PMID: 17895208 DOI: 10.1053/jscd.2000.5868] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/1999] [Accepted: 10/28/1999] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the longitudinal patterns of recovery of quality of life over the first year after stroke to understand the factors that are influential in this process. METHOD A sample of 116 stroke survivors with mild to moderate impairment was followed-up at 3 months and at 1 year after stroke onset. Changes in scores on a quality of life measure were assessed in association with changes in impairment and disability over this 9-month period. The use of rehabilitation services over the first year was also documented. RESULTS The quality of life of these survivors improved over the first year after stroke. Improvements in motor disability and depressive symptoms were found to be associated with improvements in quality of life. Additionally, survivors receiving rehabilitation therapy reported an improvement in quality of life that was independent of changes in disability and depressive symptoms. CONCLUSIONS Opportunities to enhance the quality of life of stroke survivors exist throughout the first year of recovery. Improvements in functional ability and depression are important for long-term improvements in quality of life. Rehabilitation therapy is a potentially important resource.
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Factors that affect the food choices made by girls and young women, from minority ethnic groups, living in the UK. J Hum Nutr Diet 2007; 20:311-9. [PMID: 17635308 DOI: 10.1111/j.1365-277x.2007.00766.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Lower birth weight, often found in infants from minority ethnic groups, may be partly because of the disproportionate representation of ethnic minority groups in low-income areas. To develop an intervention, to improve the nutritional intake of young women from populations at risk of low-birth-weight babies, which would be culturally sensitive and well received by the intended recipients, a community development approach was used to investigate factors that might influence food choice and the nutritional intake of girls and young women from ethnic minority groups. METHODS Focus group discussions were conducted across the UK, to explore factors that might affect the food choices of girls and young women of African and South Asian decent. The data was analysed using deductive content analysis (Qual. Soc. Res., 1, 2000, 1). Discussions were around the broad themes of buying and preparing food, eating food and dietary changes, and ideas for an intervention to improve diet. RESULTS The focus group discussions indicated that all the communities took time, price, health and availability into consideration when making food purchases. The groups were also quite similar in their use of 'Western' foods which tended to be of the fast food variety. These foods were used when there was not enough time to prepare a 'traditional' meal. CONCLUSION Many issues that affect the food choice of people who move to the UK are common within different ethnic groups. The idea of a practical intervention based on improving cooking skills was popular with all the groups.
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Kondo interactions and magnetic correlations in CePt2 nanocrystals. PHYSICAL REVIEW LETTERS 2007; 98:157206. [PMID: 17501380 DOI: 10.1103/physrevlett.98.157206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Indexed: 05/15/2023]
Abstract
The evolution of the Kondo effect and antiferromagnetic (AF) correlations with size reduction in CePt2 nanoparticles (3.1-26 nm) is studied by analysis of the temperature-dependent specific heat and magnetic susceptibility. The AF correlations diminish with size reduction. The Kondo effect predominates at small particle size with trivalent, small Kondo temperature (TK) magnetic regions coexisting with strongly mixed-valent, large TK nonmagnetic regions. We discuss the role of structural disorder, background density of states and the electronic quantum size effect on the results.
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Lattice disorder and size-induced kondo behavior in CeAl2 and CePt(2+x). PHYSICAL REVIEW LETTERS 2006; 97:097204. [PMID: 17026397 DOI: 10.1103/physrevlett.97.097204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Indexed: 05/12/2023]
Abstract
When the size of CeAl2 and CePt(2+x) particles is reduced to the nanometer scale, antiferromagnetism is suppressed and Kondo behavior predominates, with the Kondo temperature T(K) either decreasing (CeAl2) or increasing (CePt(2+x)) relative to the bulk. Local structure measurements show that these nanoparticles are significantly distorted. While such distortions should strongly affect magnetic and electronic properties, we find they cannot explain the observed changes in T(K). Other size-induced changes to the electronic structure must, therefore, play a significant role.
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Localized excitation in the hybridization gap in YbAl3. PHYSICAL REVIEW LETTERS 2006; 96:117206. [PMID: 16605862 DOI: 10.1103/physrevlett.96.117206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Indexed: 05/08/2023]
Abstract
The intermediate valence compound YbAl3 exhibits a broad magnetic excitation in the inelastic neutron scattering spectrum with characteristic energy E1 approximately 50 meV, equal to the Kondo energy (T(K) approximately 600-700 K). In the low temperature (T < T(coh) approximately 40 K) Fermi liquid state, however, a new peak in the scattering occurs at E2 approximately 33 meV, which lies in the hybridization gap that exists in this compound. We report inelastic neutron scattering results for a single-crystal sample. The scattering at energies near E1 qualitatively has the momentum (Q) dependence expected for interband scattering across the indirect gap. The scattering near E2 has a very different Q dependence: it is a weak function of Q over a large fraction of the Brillouin zone and is smallest near (1/2,1/2, 1/2). A possibility is that the peak at E2 arises from a spatially localized excitation in the hybridization gap.
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565: Prevalence of Female Pelvic Floor Disorders by Age and Race/Ethnicity in a Managed Health Care Population. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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566: Pregnancy Planning and Lifestyle Behaviors among Nonpregnant Women of Childbearing Age-Southern California, 1998–2000. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s142a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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The effect of high dose atorvastatin therapy on lipids and lipoprotein subfractions in overweight patients with type 2 diabetes. Atherosclerosis 2004; 174:141-9. [PMID: 15135263 DOI: 10.1016/j.atherosclerosis.2004.01.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2003] [Revised: 12/15/2003] [Accepted: 01/21/2004] [Indexed: 11/28/2022]
Abstract
Few data are available on the effects of high dose statin therapy on lipoprotein subfractions in type 2 diabetes. In a double blind randomised placebo-controlled trial we have studied the effects of 80 mg atorvastatin over 8 weeks on LDL, VLDL and HDL subfractions in 40 overweight type 2 diabetes patients. VLDL and LDL subfractions were prepared by density gradient ultracentrifugation. Triglycerides, cholesterol, total protein and phospholipids were measured and mass of subfractions calculated. HDL subfractions were prepared by precipitation. Atorvastatin 80 mg produced significant falls in LDL subfractions (LDL(1) 66.2 mg/dl:36.6 mg/dl, LDL(2) 118:56.6 mg/dl, LDL(3) 36.9:19.9 mg/dl all P < 0.01 relative to placebo) and VLDL subfractions (VLDL(1) 55:22.1 mg/dl, VLDL(2) 40.1:19.1 mg/dl, VLDL(3) 52.6:30 mg/dl all P < 0.01 relative to placebo). There was no change in the proportion of LDL present as LDL(3). There was a reduction in the proportion of VLDL as VLDL(1) and a reciprocal increase in the proportion as VLDL(3). Changes in VLDL subfractions were associated with changes in lipid composition, particularly a reduction in cholesterol ester and a reduction in the cholesterol ester/triglyceride ratio. Effects on HDL subfractions were largely neutral. High dose atorvastatin produces favourable effects on lipoprotein subfractions in type 2 diabetes which may enhance antiatherogenic potential.
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Abstract
There is currently no real treatment for blinding disorders that stem from the degeneration of cells in the retina and affect at least 50 million individuals worldwide. The excitement that accompanied the first studies showing the potential of retinal cell transplantation to alleviate the progress of blindness in such diseases as retinitis pigmentosa and age-related macular degeneration has lost some of its momentum, as attempts to apply research to the clinic have failed so far to provide effective treatments. What these studies have shown, however, is not that the approach is flawed but rather that the steps that need to be taken to achieve a viable, clinical treatment are many. This review summarizes the course of retinal transplant studies and points to obstacles that still need to be overcome to improve graft survival and efficacy and to develop a protocol that is effective in a clinical setting. Emphasis is given particularly to the consequences of introducing transplants to sites that have been considered immunologically privileged and to the role of the major histocompatibility complex classes I and II molecules in graft survival and rejection.
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Dependence of the effective masses in YbAl3 on magnetic field and disorder. PHYSICAL REVIEW LETTERS 2003; 90:166404. [PMID: 12731987 DOI: 10.1103/physrevlett.90.166404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2002] [Indexed: 05/24/2023]
Abstract
The susceptibility and specific heat--and hence the effective mass--of the intermediate valence compound YbAl3 show anomalous enhancement below the Fermi liquid temperature T(coh) approximately 40 K. We show that these anomalies are suppressed by alloying in Yb1-xLuxAl3 indicating high sensitivity to lattice coherence. The de Haas-van Alphen effective masses for key branches of the Fermi surface are reduced by magnetic fields B>40 T. We argue that this reduction does not arise from 4f polarization but reflects renormalization of the quasiparticle states by the field.
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Abstract
Fluvastatin was the first wholly synthetic statin to the market and is effective in reducing total and low density lipoprotein cholesterol, which translates into reductions in coronary heart disease events. The Lescol Intervention Prevention Study has established the effectiveness of the early use of statins in reducing recurrent events in high-risk patients with coronary heart disease post percutaneous coronary interventions. Fluvastatin is well-tolerated with few side effects. The occurrence of significant abnormalities in liver enzymes is infrequent, and the risk of myositis and rhabdomyolysis seems to be less than with other statins. There have been no reports of fatal rhabdomyolysis to date. The potential for drug interactions with fluvastatin is low. It seems safe in combination with cyclosporin and there have been few reports of rhabdomyolysis when using fluvastatin in combination with other lipid-lowering agents. It is nevertheless important to be vigilant for this potentially important side effect and, as with other statins, inform patients of the potential risk and suggestive symptoms. Fluvastatin provides a useful option in treating hypercholesterolaemia in patients at high risk of coronary heart disease.
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Two energy scales and slow crossover in YbAl3. PHYSICAL REVIEW LETTERS 2002; 88:117201. [PMID: 11909426 DOI: 10.1103/physrevlett.88.117201] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2001] [Revised: 01/30/2002] [Indexed: 05/23/2023]
Abstract
Experimental results for the susceptibility, magnetization, specific heat, 4f occupation number, Hall effect, and magnetoresistance for single crystals of the intermediate valence (IV) compound YbAl3 show that, in addition to the Kondo temperature scale T(K) approximately 670 K, there is a low temperature scale T(coh) approximately 30-40 K for the onset of Fermi liquid coherence. Furthermore, the crossover from the low temperature Fermi liquid regime to the high temperature local moment regime is slower than predicted by the Anderson impurity model. We suggest that these effects are generic for IV compounds and we discuss them in terms of the theory of the Anderson lattice.
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Kinetic and Kinematic Responses of the RID2a, Hybrid III and Human Volunteers in Low-Speed Rear-End Collisions. STAPP CAR CRASH JOURNAL 2001; 45:239-56. [PMID: 17458748 DOI: 10.4271/2001-22-0011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
An anthropomorphic test device (ATD) which accurately models the kinematic and kinetic responses of human subjects during head restraint contact in low-speed rear-end collisions is needed to evaluate present and future seat and vehicle designs. The primary goal of this study was to quantify the biofidelity of a new rear-impact ATD, the RID2a, by comparing its dynamic response to those of human subjects under identical test conditions. For this study, a RID2a and a Hybrid III ATD were each exposed to 10 low-speed rear-end collisions: five at a speed change of 4 km/h and five at a speed change of 8 km/h. Sagittal plane kinematics of the head and upper torso, head restraint contact forces, and the reaction loads and moment at the atlanto-occipital joint were determined and compared to the response of eleven male human subjects. Both ATDs produced repeatable response corridors. As observed by others, the Hybrid III did not replicate many features of the human response. Aside from the vertical response of the head and T1 in the global reference frame, the kinematic and kinetic responses of the RID2a reproduced most features of the human response. Head restraint forces observed in both the human subjects and the RID2a contained large vertical components that placed the neck in tension during head restraint contact. The results of this study indicated that the RID2a was able to model the overall kinematic and kinetic responses relevant to some recently-proposed mechanisms of whiplash injury.
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Screening for diabetes in general practice: cross sectional population study. BMJ (CLINICAL RESEARCH ED.) 2001; 323:548-51. [PMID: 11546702 PMCID: PMC48161 DOI: 10.1136/bmj.323.7312.548] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To assess the policy proposed by the American Diabetes Association of universal screening in general practice of all patients aged over 45 years for diabetes. DESIGN Cross sectional population study. SETTING Local general practice in the United Kingdom. PARTICIPANTS All patients aged over 45 not known to have diabetes. MAIN OUTCOME MEASURES Prevalence of diabetes in the screened population, cardiovascular risk profile of patients diagnosed as having diabetes after screening. RESULTS Of 2481 patients aged over 45 and not known to have diabetes, 876 attended for screening. There were no significant demographic differences between the screened and unscreened patients. Prevalence of diabetes in patients with age as a sole risk factor was 0.2% (95% confidence interval 0% to 1.4%). Prevalence of diabetes in patients with age and one or more other risk factors (hypertension, obesity, or a family history of diabetes) was 2.8% (1.6% to 4.7%). Four hours a week for a year would be needed to screen all people over 45 in the practice's population; about half this time would be needed to screen patients with risk factors other than age. More than 80% of patients newly diagnosed as having diabetes had a 10 year risk of coronary heart disease >15%, 73% (45% to 92%) were hypertensive, and 73% (45% to 92%) had a cholesterol concentration >5 mmol/l. CONCLUSIONS Screening for diabetes in general practice by measuring fasting blood glucose is feasible but has a very low yield in patients whose sole risk factor for diabetes is age over 45. Screening in a low risk population would best be targeted at patients with multiple risk factors.
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Actos (pioglitazone): a new treatment for type 2 diabetes. HOSPITAL MEDICINE (LONDON, ENGLAND : 1998) 2001; 62:411-6. [PMID: 11480129 DOI: 10.12968/hosp.2001.62.7.1611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Type 2 diabetes is increasingly common and can be difficult to control. By directly targeting insulin resistance, the thiazolidinediones offer a new mode of treatment. Here, the pharmacology, clinical trial evidence, side-effects and current clinical uses of pioglitazone are reviewed.
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Abstract
It has been shown that photoreceptor degeneration can be limited in experimental animals by transplantation of fresh RPE to the subretinal space. There is also evidence that retinal cell transplants can be used to reconstruct retinal circuitry in dystrophic animals. Here we describe and review recent developments that highlight the necessary steps that should be taken prior to embarking on clinical trials in humans.
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Progressive visual sensitivity loss in the Royal College of Surgeons rat: perimetric study in the superior colliculus. Neuroscience 2001; 103:51-63. [PMID: 11311787 DOI: 10.1016/s0306-4522(00)00557-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The Royal College of Surgeons rat has a retinal pigment epithelial cell defect which causes a progressive loss of rods occurring primarily over the first few months of life. We have studied the consequences of this degenerative process on visual sensitivity across the visual field. Sensitivities were determined in the superior colliculus for unit responses recorded from 22 days up to one year of age from sites encompassing the whole visual field representation. Following visual sensitivity assessment, retinae were examined anatomically at the light and electron microscopic level. At 22 days of age, sensitivities in dystrophic rats were comparable to those of non-dystrophics at any age (40+/-1 and 41+/-1dB, respectively), despite the fact that signs of degenerative events were clear at the electron microscopic level, including presence of pyknotic photoreceptor nuclei, disorganised outer segments and accumulation of debris. However, loss in sensitivity was first detected only at 28-36 days of age (27+/-4dB). From then on, sensitivities progressively decreased to reach a plateau by 180-240 days (4+/-2dB). Starting around 90 days and onward, there was a positive gradient of sensitivities from temporal to nasal field. Drops in visual sensitivity were parallelled by several changes in visual response properties, including prolonged latency, inconsistent responsiveness, appearance of bursting spontaneous activity and activation of units by stimuli presented outside their classical receptive fields. The measure of visual sensitivities by recording visual responses at specific sites in the superior colliculus provides a reliable point-to-point assessment of retinal function comparable to visual perimetry testing in humans. This experimental approach provides the background for answering questions arising during the development of potential experimental therapies for retinal degeneration using animal models like the Royal College of Surgeons rat.
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Split sample analysis of serum folate levels after 18 days in frozen storage. Clin Lab 2001; 46:483-6. [PMID: 11034534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Reliable measurement of folate is becoming increasingly important as links between dietary folate intake, the use of vitamins containing folic acid, and health outcomes such as birth defects and cardiovascular disease are identified. This study was undertaken to formally assess whether the quantity of folate in serum declines after the serum is frozen and stored. Blood samples from 83 pregnant women were tested for serum folate shortly after collection and again after 18 days of storage at -20 degrees C. A shift from higher to lower serum folate categories was observed after 18 days of storage. For the first test, 40.9 % of the samples were > or = 20 microg/L compared with 19.3 % of the test results on second test. For the 75 samples in the quantifiable range (< 40 microg/L), a mean decrease of 5.0 microg/L (+/- 0.5) of serum folate was observed (p < 0.0001). When compared to serum samples stored in a non frost-free freezer at -20 degrees C or -70 degrees C, serum stored in a frost-free freezer at -20 degrees C for even a short period of time may be relatively unstable and sensitive to minor temperature fluctuations associated with the freeze-thaw cycles.
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Lattice disorder in strongly correlated lanthanide and actinide intermetallics. JOURNAL OF SYNCHROTRON RADIATION 2001; 8:191-195. [PMID: 11512723 DOI: 10.1107/s0909049500019026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2000] [Accepted: 11/28/2000] [Indexed: 05/23/2023]
Abstract
Lanthanide and actinide intermetallic compounds display a wide range of correlated-electron behavior, including ferromagnetism, antiferromagnetism, nonmagnetic (Kondo) ground states, and so-called 'non-Fermi liquid' (NFL) behavior. The interaction between f electrons and the conduction band is a dominant factor in determining the ground state of a given system. However, lattice disorder can create a distribution of interactions, generating unusual physical properties. These properties may include NFL behavior in many materials. In addition, lattice disorder can cause deviations from standard Kondo behavior that is less severe than NFL behavior. A review of the lattice disorder mechanism within a tight-binding model is presented, along with measurements of the YbBCu4 and UPd(x)Cu(5-x) systems, demonstrating the applicability of the model. These measurements indicate that while the YbBCu4 system appears to be well ordered, both site interchange and continuous bond-length disorder occur in the UPd(x)Cu(5-x) series. Nevertheless, the measured bond-length disorder in UPdCu4 does not appear to be enough to explain the NFL properties simply with the Kondo disorder model.
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Abstract
Our previous work showed that stereotaxic microextrusion of columns of purified peripheral nerve-derived Schwann cells into the thalamus of syngeneic adult rats induces host axons to grow into the column and form a new fiber tract. Here we describe the time course of cellular events that lead to the formation of this new tract. At 2 h postoperation, numerous OX42-positive microglia accumulated at the graft-host interface, after which donor columns became progressively and heavily infiltrated by microglia/macrophages that took on an elongated morphology in parallel with the highly orientated processes of the donor Schwann cells. The penetration of host astrocytic processes into the Schwann cell columns was substantially slower in onset, being first detected at 4 days postoperation. This event was contemporaneous with the in-growth of host thalamic axons. Between 7 and 14 days postoperation, GFAP-positive astrocytes became fully incorporated into the transplants, where they too adopted an elongated form, orientated in parallel with the longitudinal axis of the graft. Thus, the columns became a mosaic of elongated and highly orientated donor Schwann cells intimately mingled with host microglia, astrocytes, and numerous, largely unbranched 200-kDa neurofilament-positive axons from the adjacent thalamus. Electron microscopy demonstrated that the processes of donor Schwann cells and host astrocytes within the column formed tightly packed bundles that were surrounded by a partial or complete basal lamina. Control columns, formed by extruding freeze-thaw-killed Schwann cells or purified peripheral nerve fibroblasts induced a reactive injury response by the adjacent host microglia and astrocytes, but neither host astrocytes nor neurofilament-positive axons were incorporated into the columns. A better understanding of the mechanisms that regulate the interactions between donor and host glia should facilitate improved integration of such grafts and enhance their potential for inducing tissue repair.
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Inelastic magnetic neutron scattering in CeT2Si2(T=Au, Pd, Ru or Pt): crystal fields and quasi-elastic scattering. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/21/6/016] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
Domestic violence is a complex issue at both an individual and public health level. Barriers to disclosure often lie with the doctor rather than the victim. Assessment of risk and devising a safety plan are important steps for the doctor to undertake with the victim. Recommendations for joint counselling or marriage guidance for the couple are usually not appropriate. The efficacy of population screening for domestic violence has not yet been demonstrated. More limited opportunistic screening is recommended, especially in the emergency department, mental health and obstetric settings, and general practice. Health professionals can be a bridge to resources within the community, but this requires knowledge of and liaison with those services.
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Pioglitazone. Int J Clin Pract 2000; 54:614-8. [PMID: 11220991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Pioglitazone is a thiazolidinedione. As a PPAR-gamma agonist it alters the expression of a number of genes, resulting in a reduction in insulin resistance. Clinical trial data involving over 4500 patients with type 2 diabetes suggest it is effective both as monotherapy and in combination with sulphonylureas, metformin and insulin, producing both significant falls in HbA1c and favourable improvements in lipid parameters. It is well tolerated, with a low incidence of side-effects. Unlike troglitazone, its use has not been associated with hepatotoxicity. It has recently been licensed in the US for use as monotherapy and in combination with insulin, metformin and sulphonylureas. Its European license is more restrictive, allowing use in combination with metformin, and in combination with sulphonylureas in those intolerant of metformin. It provides a useful new option in the treatment of type 2 diabetes mellitus.
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The influence of intrapartum antibiotics on the clinical spectrum of early-onset group B streptococcal infection in term infants. Pediatrics 2000; 106:244-50. [PMID: 10920146 DOI: 10.1542/peds.106.2.244] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE The use of intrapartum antibiotics to prevent early-onset group B streptococcal (EOGBS) infection has left pediatricians in a quandary about the appropriate evaluation and treatment of infants at risk for this infection. The aim of this study was to determine whether intrapartum antibiotic prophylaxis changed the constellation and timing of onset of clinical signs of group B streptococcal (GBS) infection in term infants. METHODOLOGY We conducted a retrospective chart review of infants who had EOGBS infection and were born in Southern California Kaiser Permanente Hospitals from 1988 through 1996. Objective criteria were used to ascertain maternal risk of infection, intrapartum antibiotic prophylaxis, and onset of clinical signs of infection. RESULTS Three hundred nineteen infants with EOGBS sepsis, bacteremia, or clinically suspected infection were identified from a population of 277 912 live births. Of the 172 term infants with culture-positive infection who had clinical signs of infection, 95% exhibited them in the first 24 hours of life. All of the infants exposed to intrapartum antibiotics became ill within the first 24 hours of life. CONCLUSIONS Exposure to antibiotics during labor did not change the clinical spectrum of disease or the onset of clinical signs of infection within 24 hours of birth for term infants with EOGBS infection. A 48-hour stay is not required to monitor asymptomatic term infants exposed to intrapartum antibiotics for onset of GBS infection.
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