bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predictors of insulin sensitivity in Type 2 diabetes mellitus
Authors: Bonora E. , Targher G. , Alberiche M. , Formentini G. , Calcaterra F. , Lombardi S. , Marini F. , Poli M. , Zenari L. , Raffaelli A. , Perbellini S. , Zenere M. B. , Saggiani F. , Bonadonna R. C. , Muggeo M. 
Published: March 2003

AbstractAims To identify the independent predictors of insulin sensitivity in Type 2 diabetes, and to establish whether isolated Type 2 diabetes (i.e. diabetes without overweight, dyslipidaemia and hypertension) is a condition of insulin resistance.Methods We examined 45 patients with non‐insulin‐treated Type 2 diabetes undergoing a 4‐h euglycaemic hyperinsulinaemic clamp (20 mU/m2 per min) combined with 3H‐3‐D‐glucose and 14C‐U‐glucose infusions and indirect calorimetry. We also examined 1366 patients with non‐insulin‐treated Type 2 diabetes randomly selected among those attending the Diabetes Clinic and in whom insulin resistance was estimated by Homeostasis Model Assessment (HOMA‐IR).Results In the 45 patients undergoing glucose clamp studies, insulin‐mediated total glucose disposal (TGD) was independently and negatively associated with systolic blood pressure (standardized β coefficient = −0.407, P = 0.003), plasma triglycerides (β= −0.355, P = 0.007), and HbA1c (β= −0.350, P = 0.008). The overall variability of TGD explained by these variables was 53%. Overweight diabetic subjects with central fat distribution, hypertension, hypertriglyceridaemia and poor glycometabolic control had insulin‐mediated TGD values markedly lower than their lean counterparts without hypertension, with normal triglycerides, and with good glycometabolic control (16 ± 5 vs. 31 ± 10 µmol/min per kg lean body mass, P < 0.01). Nevertheless, the latter still were markedly insulin‐resistant when compared with sex‐ and age‐matched non‐diabetic control subjects (31 ± 10 vs. 54 ± 13 µmol/min per kg lean body mass, P < 0.01). In the 1366 Type 2 diabetic patients of the epidemiological study, HOMA‐IR value was independently associated with HbA1c (β = 0.283, P < 0.0001), plasma triglycerides (β = 0.246, P < 0.0001), body mass index (β = 0.139, P < 0.001), waist girth (β = 0.124, P < 0.001) and hypertension (β = 0.066, P = 0.006).Conclusion Overweight, central fat distribution, dyslipidaemia, hypertension and poor glycometabolic control are strong independent predictors of insulin resistance in Type 2 diabetes. However, reduced insulin sensitivity can be found even when Type 2 diabetes is isolated and well controlled.Diabet. Med. 19, 535–542 (2002)
The relationship between blood glucose excursions and painful diabetic peripheral neuropathy: a pilot study
Authors: Oyibo S. O. , Prasad Y. D. M. , Jackson N. J. , Jude E. B. , Boulton A. J. M. 
Published: March 2003

AbstractAims Peripheral neuropathy affects 30% of Type 1 diabetic patients. Unfortunately, 10–20% of affected patients have disabling symptoms. The aim of this study was to examine the relationship between blood glucose excursions and pain in patients with symptomatic diabetic neuropathy.Methods Twenty Type 1 diabetic patients with peripheral neuropathy (10 painful and 10 painless) wore a continuous glucose monitoring system for 3 days. Symptomatic patients kept a daily pain score diary. The mean amplitude of glycaemic excursions (MAGE) and the M‐values (measure of glucose deviations from an arbitrarily selected point) were calculated.Results Groups were matched for (mean ± sd) age: 52.0
±
11.1 years; duration of diabetes: 24.8
±
10.7 years; HbA1c: 9.7
±
2.3%; duration of neuropathy: 5.6
±
2.6 years; and CGMS performance. The painful group had a greater mean glucose (12.1
±
2.9 mmol/l vs. 9.3
±
1.9 mmol/l, P

=
0.02), a greater M‐value (68.4 vs. 31.1, P

=
0.02) and more glycaemic excursions (13 vs. 10, P < 0.01), compared with the painless group. However, there was no difference in the MAGE between both groups, and no correlation between the number of glycaemic excursions and the number of painful episodes in the painful group.Conclusions Patients with painful neuropathy have greater glucose flux and possibly poorer diabetes control, compared with patients with painless neuropathy.
Affluence is not related to delay in diagnosis of Type 2 diabetes as judged by the development of diabetic retinopathy
Authors: Litwin A. S. , Clover A. , Hodgkins P. R. , Luff A. J. 
Published: March 2003

AbstractAim To determine the relationship between affluence and the presence of diabetic retinopathy at time of diagnosis of Type 2 diabetes.Methods Records of patients held by Southampton Retinal Screening Programme were examined. Patients (n = 1844) newly diagnosed with Type 2 diabetes and subsequently receiving photographic retinal screening within 24 months were selected. Townsend scores for social deprivation were calculated and the patients with and without retinopathy at first screening were then compared.Results No significant difference was found in the median Townsend score of those people with (−0.2, interquartile range (IQR) −3.7 to 3.8) and those without (−0.5, IQR −3.3 to 3.6) diabetic retinopathy at first screening after diagnosis of Type 2 diabetes (P = 0.6).Conclusion The relative affluence of the area in which a person lives, as judged by postcode, does not appear to predict likelihood of diabetic retinopathy at diagnosis of Type 2 diabetes.
Proposed diagnostic thresholds for gestational diabetes mellitus according to a 75‐g oral glucose tolerance test. Maternal and perinatal outcomes in 3260 Danish women
Authors: Jensen D. M. , Damm P. , Sørensen B. , Mølsted‐Pedersen L. , Westergaard J. G. , Korsholm L. , Ovesen P. , Beck‐Nielsen H. 
Published: March 2003

AbstractAims To study if established diagnostic threshold values for gestational diabetes based on a 75‐g, 2‐h oral glucose tolerance test can be supported by maternal and perinatal outcomes.Methods Historical cohort study of 3260 pregnant women examined for gestational diabetes on the basis of risk indicators. Information on oral glucose tolerance test results and clinical outcomes were collected from medical records.Results There was an increased risk of delivering a macrosomic infant in women with 2‐h capillary blood glucose of 7.8–8.9 mmol/l compared with women with 2‐h glucose < 7.8 mmol/l. Despite treatment, 2‐h glucose of 9.0–11.0 mmol/l and ≥ 11.1 mmol/l were both associated with increased rates of macrosomia, spontaneous preterm delivery, hypertensive complications, and neonatal hypoglycaemia. Adverse outcomes tended to be more frequent in women with 2‐h glucose ≥ 11.1 mmol/l than in women with 2‐h glucose of 9.0–11.0 mmol/l.Conclusions The risk for several maternal and perinatal complications increased with the diagnostic threshold for 2‐h glucose. Large‐scale blinded studies are needed to clarify the question of a clinically meaningful diagnosis of gestational diabetes mellitus. Until these results are available, a 2‐h threshold level of 9.0 mmol/l after a 75‐g oral glucose tolerance test seems acceptable.
Methicillin‐resistant Staphylococcus aureus in the diabetic foot clinic: a worsening problem
Authors: Dang C. N. , Prasad Y. D. M. , Boulton A. J. M. , Jude E. B. 
Published: March 2003

AbstractAims  To determine if there has been a change in the prevalence of pathogenic organisms in foot ulcers in diabetic patients in 2001 compared with our previous study in 1998.Methods  A retrospective analysis of wound swabs taken from infected foot ulcers in diabetic patients attending the outpatient clinic in the Manchester Foot Hospital over a twelve‐month period. A total of 63 patients with positive wound swabs were identified.Results  Gram‐positive aerobic bacteria still predominate (84.2%) and the commonest single isolate remains Staphylococcus aureus (79.0%) which is higher than we previously reported. MRSA was isolated in 30.2% of the patients which is almost double the proportion of MRSA‐affected patients three years ago. This did not appear to be related to prior antibiotic usage. There was no increase in hospitalisation because of MRSA infection.Conclusions  The problem of MRSA continues to increase despite the precautions taken to prevent MRSA spread. There is a need for a multi‐centre study looking into the prevalence of MRSA in diabetic foot ulcer and how this can be reduced in the diabetic foot clinic.
The role of fire disturbance for global vegetation dynamics: coupling fire into a Dynamic Global Vegetation Model
Authors: Thonicke Kirsten , Venevsky Sergey , Sitch Stephen , Cramer Wolfgang 
Published: March 2003

AbstractDisturbances from fire, wind‐throw, insects and other herbivores are, besides climate, CO2, and soils, critical factors for composition, structure and dynamics of most vegetation. To simulate the influence of fire on the dynamic equilibrium, as well as on potential change, of vegetation at the global scale, we have developed a fire model, running inside the modular framework of the Lund–Potsdam–Jena Dynamic Global Vegetation Model (LPJ‐DGVM).Estimated litter moisture is the main driver of day‐to‐day fire probability. The length of the fire season is used to estimate the fractional area of a grid cell which is burnt in a given year. This affected area is converted into an average fire return interval which can be compared to observations.When driven by observed climate for the 20th century (at a 0.5° longitude/latitude resolution), the model yielded fire return intervals in good agreement with observations for many regions (except parts of semiarid Africa and boreal Siberia). We suggest that further improvement for these regions must involve additional process descriptions such as permafrost and fuel/fire dynamics.
Mammals on mountainsides: elevational patterns of diversity
Authors: Brown James H. 
Published: March 2003

AbstractThe four major papers in this special feature present and interpret data from field studies on the distributions and diversity of small mammals in elevational gradients on mountains in the Philippines, Borneo, southern Mexico and western United States. In the introductory paper, Lomolino places these studies in the context of historical, methodological and conceptual themes in contemporary biogeography. In this final paper, I focus on some important similarities and interesting differences among the four case studies. All of the studies provide evidence for the influence of ecological factors, such as climate, productivity and habitat heterogeneity, on mammalian diversity. All also provide evidence for the influence of historical dispersal, extinction, and speciation events. Perhaps the most interesting result is the documentation of a frequent, but not universal, peak in species diversity at some elevation intermediate between the base and peak of a mountain. Efforts to understand the mechanistic basis for this pattern — and why it differs from the continuous decrease in diversity from the equator to the poles — promise to contribute to developing a general theoretical explanation for the major patterns of biodiversity on earth.
Elevation gradients of species‐density: historical and prospective views
Authors: Lomolino MARK. V. 
Published: March 2003

AbstractStudies of elevation clines in diversity and composition of ecological communities date back to the origins of biogeography. A modern resurgence of interests in these elevational clines is likely to contribute important insights for developing a more general theory of species diversity. In order to gain a more comprehensive understanding of geographical clines in diversity, the research programme for montane biogeography should include statistically rigorous tests of apparent patterns, comparisons of patterns among regions and taxonomic or ecological groups of species, and analyses of clines in environmental variables concurrent with biogeographical surveys. The conceptual framework for this research programme should be based on the assumption that elevational gradients in species diversity result from a combination of ecological and evolutionary processes, rather than the presumed independent effects of one overriding force. Given that montane ecosystems are hot spots of biological diversity, an expanded and integrated programme for biogeographic surveys in montane regions should provide valuable insights for conservation biologists.
Breaking taboos in the tropics: incest promotes colonization by wood‐boring beetles
Authors: Jordal Bjarte H. , Beaver Roger A. , Kirkendall Lawrence R. 
Published: March 2003

Abstract

Inbreeding and parthenogenesis are especially frequent in colonizing species of plants and animals, and inbreeding in wood‐boring species in the weevil families Scolytinae and Platypodidae is especially common on small islands. In order to study the relationship between colonization success, island attributes and mating system in these beetles, we analysed the relative proportions of inbreeders and outbreeders for 45 Pacific and Old World tropical islands plus two adjacent mainland sites, and scored islands for size, distance from nearest source population, and maximum altitude.
The numbers of wood‐borer species decreased with decreasing island size, as expected; the degree of isolation and maximum island altitude had negligible effects on total species numbers.
Numbers of outbreeding species decreased more rapidly with island size than did those of inbreeders. Comparing species with similar ecology (e.g. ambrosia beetles) showed that this difference was best explained by differential success in colonization, rather than by differences in resource utilization or sampling biases. This conclusion was further supported by analyses of data from small islands, which suggested that outbreeding species have a higher degree of endemism and that inbreeding species are generally more widespread.
Recently established small populations necessarily go through a period of severe inbreeding, which should affect inbreeding species much less than outbreeding ones. In addition, non‐genetic ecological and behavioural (‘Allee’) effects are also expected to reduce the success of outbreeding colonists much more than that of inbreeders: compared with inbreeders, outbreeders are expected to have slower growth rates, have greater difficulties with mate‐location and be vulnerable to random extinction over a longer period.
The concept of the taxon cycle in biogeography
Authors: Ricklefs Robert E. , Bermingham Eldredge 
Published: March 2003

AbstractTaxon cycles are sequential phases of expansion and contraction of the ranges of species, associated generally with shifts in ecological distribution. The important contribution of the taxon cycle to biogeographical analysis is its emphasis on evolutionary and ecological interactions among colonizing and resident species, which influence their extinction dynamics and establish patterns of geographical distribution. Taxon cycles were inferred originally from the distribution of species across island archipelagos, where a correlation was noted between gaps in island occupancy and the degree of phenotypic differentiation. This pattern implied that phases of colonization were followed by range contraction, while endemic Antillean species that were undifferentiated between islands suggested secondary expansion and the beginning of a new cycle. This interpretation was met with scepticism, but reconstruction of phylogenetic relationships from gene sequences has now permitted us to characterize taxon cycles in Lesser Antillean birds. The relative timing of phases of the cycle can be deduced from genetic divergence between island populations. We have found that taxon cycles have periods in the order of 106 years and that cycles in different lineages occur independently of each other and independently of Pleistocene climate cycles. Individual island populations may persist for several millions of years on the larger islands of the Lesser Antilles; occasional expansion phases lead to the replacement of island populations that have disappeared, thus reducing the archipelago‐wide rate of extinction to nil. What drives taxon cycles is unknown, but we speculate that they may be caused by co‐evolution with enemy populations, and a probable mechanism would involve infrequent mutations influencing parasite virulence and avian host disease resistance. Taxon cycles undoubtedly occur on continents, but the geographical configuration of island archipelagos reveals more clearly their presence and invites their study.
Distributional change and conservation on the Andean flank: a palaeoecological perspective
Authors: Bush Mark B. 
Published: March 2003

ABSTRACTAim To review the insights that palaeoecology can offer on the threat posed to Andean communities by global climate change.Location The geographical focus is the eastern flank of the tropical Andes, with particular reference to Peru.Method The article presents a synthetic review of the problem.Results Species‐rich communities of the eastern Andean flank are threatened both by development and climate change. If, as predicted, the cloudbase and frost line lifts 600 m elevation this century, there will be a substantial loss of cloud forest habitat. Palaeoecology provides insights on the location and nature of past ecotones, the continuity of niche availability, and estimates for rates and modes of migration. With further warming and drying of lower montane regions, upslope migration of species will be individualistic: a new equilibrium with the altered climate is unlikely to be attained. The zone of agriculture will move upslope faster than the migrating trees and so landscape conversion will negate the ability of some species to respond to the new conditions. Conservation of the lower reaches of modern cloud forest is advocated as a means to limit this foreseeable extinction event.Main Conclusions Climate change will induce changes in plant and animal communities. Human disturbance will invade climatically marginal agricultural lands at the pace of climate change. Rapid migratory response such as that witnessed at the onset of the Holocene may not be evident as climates warm, because Holocene climatic stability has reduced outlying upslope populations that may have served as expansion nuclei. Conservation must aim to maintain plant and animal niches, rather than particular communities of species.
Environmental factors and vegetation composition, Lefka Ori massif, Crete, S. Aegean
Authors: Vogiatzakis I. N. , Griffiths G. H. , Mannion A. M. 
Published: March 2003

ABSTRACTAim The aim of this study was to explore the environmental factors that determine the spatial distribution of oro‐mediterranean and alti‐mediterranean plant communities in Crete.Location The paper provides a quantitative analysis of vegetation–environment relationships for two study areas within the Lefka Ori massif Crete, a proposed Natura 2000 site.Methods Eleven environmental variables were recorded: altitude, slope, aspect, percentage of bare rock, percentage of unvegetated ground, soil depth, pH, organic matter content and percentages of sand, silt and clay content. Classification of the vegetation was based on twinspan, while detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) were used to identify environmental gradients linked to community distribution.Results One hundred and twenty‐five species were recorded from 120 plots located within the two study areas. Forty‐seven of the recorded species are endemic, belonging to 35 families. Hemicryptophytes and chamaephytes were the most frequent, suggesting a typical oro‐mediterranean life form spectrum. The samples were classified into five main community types and one transitional. The main gradients, identified by CCA, were altitude and surface cover type in the North‐west site, while in the Central site the gradients were soil formation‐development and surface cover type.Main conclusions The use of classification in combination with ordination techniques resulted in a good discrimination between plant communities and a greater understanding of controlling environmental factors. The methodology adopted can be employed for improving baseline information on plant community ecology and distribution in Mediterranean mountain zones.
The coincidence of people and biodiversity in Europe
Authors: Araújo Miguel B. 
Published: March 2003

ABSTRACTA positive correlation between human population density and species richness has been recorded across the tropics. Here I investigate whether this correlation holds true for Europe. Analyses reveal a positive correlation between human population density and plant (rho = 0.505), mammal (rho = 0.471) and reptile and amphibian (rho = 0.556) species richness. The results are largely concordant with those obtained in similar studies for Africa. However, contrary to previous analyses, the correlation found between people and breeding bird species richness (rho = 0.186) was weak. Of three measures of endemism used, only combined European endemic species richness correlated with human density (rho = 0.437). Richness among combined restricted‐range European endemics was not correlated (rho = 0.095) with human density, while richness among all combined restricted‐range species was only weakly correlated with human density (rho = 0.167). The results partially support the idea of a correlation between people and biodiversity, although there are some important exceptions. Discussion of possible mechanisms underling the observed patterns is undertaken.
Genomic structure of the mouse trefoil factor (Tff) gene cluster in 17q
Authors: Kayademir Tuncay , Rosewell Ian , Blin Nikolaus , Gött Peter 
Published: March 2003

AbstractIntroduction In vertebrates, trefoil factor (TFF) domain peptides constitute a class of peptides secreted by the mucous epithelia of the gastrointestinal tract. These peptides promote healing and protection in the gastrointestinal tract. Since the three known human genes are clustered in 21q22.3, a similar arrangement in a paralogous region was possible in mice. The murine intestinal trefoil factor is encoded by the gene Tff3 and was mapped to murine chromosome 17.Materials and methods Three bacterial and one yeast artificial chromosome recombinants (BAC and YAC) were identified and used for characterisation by PCR, restriction mapping, hybridisation, and fluorescence in situ hybridisation (FISH).Results and discussion Here we have characterised the genomic structure of all three mouse Tff genes starting with a contig formed by one YAC and three BACs. In a similar fashion to the TFF gene cluster in humans, the Tff genes cover a region of approx. 40 kb in the transcriptional order Tff1–Tff2–Tff3 and localised on mouse chromosome 17. Based on this conserved genomic structure, we propose a model of how mammalian TFF genes may have evolved by exon duplication and unequal crossing over.