bluuebunny/crossref_metadata_2025 huggingface dataset:
An economic evaluation of atenolol vs. captopril in patients with Type 2 diabetes (UKPDS 54)
Authors: Gray A. , Clarke P. , Raikou M. , Adler A. , Stevens R. , Neil A. , Cull C. , Stratton I. , Holman R. ,   the UKPDS Group
Published: March 2003

Aims To compare the net cost of a tight blood pressure control policy with an angiotensin converting enzyme inhibitor (captopril) or β blocker (atenolol) in patients with Type 2 diabetes.

Design A cost‐effectiveness analysis based on outcomes and resources used in a randomized controlled trial and assumptions regarding the use of these therapies in a general practice setting.

Setting Twenty United Kingdom Prospective Diabetes Study Hospital‐based clinics in England, Scotland and Northern Ireland.

Subjects Hypertensive patients (n= 758) with Type 2 diabetes (mean age 56 years, mean blood pressure 159/94 mmHg), 400 of whom were allocated to the angiotensin converting enzyme inhibitor captopril and 358 to the β blocker atenolol.

Main outcome measuresLife expectancy and mean cost per patient.

ResultsThere was no statistically significant difference in life expectancy between groups. The cost per patient over the trial period was £6485 in the captopril group, compared with £5550 in the atenolol group, an average cost difference of £935 (95% confidence interval £188, £1682). This 14% reduction arose partly because of lower drug prices, and also because of significantly fewer and shorter hospitalizations in the atenolol group, and despite higher antidiabetic drug costs in the atenolol group.

ConclusionsTreatment of hypertensive patients with Type 2 diabetes using atenolol or captopril was equally effective. However, total costs were significantly lower in the atenolol group.

Diabet. Med. 18, 438–444 (2001)
Fulminant autoimmune Type 1 diabetes during interferon‐alpha therapy: a case of Th1‐mediated disease?
Authors: Bosi E. , Minelli R. , Bazzigaluppi E. , Salvi M.
Published: March 2003

Aim  A case of autoimmune Type 1 diabetes with some unique characteristics developing in a 29‐year‐old male during treatment with interferon‐alpha (IFN‐α) for chronic hepatitis C virus (HCV) hepatitis is reported.

Patient and methods In this patient IFN‐α treatment was well tolerated and successful in the cure of hepatitis with eradication of HCV infection within 3 months, but at 8.5 months Type 1 diabetes appeared and insulin therapy was started and maintained thereafter. HLA class II molecular typing was determined and retrospective measurement of islet cell (ICA), glutamate decarboxylase (GADA), tyrosin phosphatase IA‐2 (IA‐2A) and insulin (IAA) antibodies was performed in serum samples obtained before and at 0.5, 1, 2, 3, 4, 5, 6, 8.5, 10 and 13 months after the beginning of IFN‐α treatment.

Results Complete HLA class II typing was consistent with homozygosity for the HLA DRB *03011, DQA1 *0501, DQB1 *0201 haplotype. All autoantibodies were undetectable prior to IFN‐α therapy and remained undetectable up to 6 months of treatment; at 8.5 months, at the time of diabetes onset, ICA were detectable at low titre while GADA were present at high titre. Both ICA and GADA persisted at high levels in subsequent samples. IA‐2A remained undetectable in all serum samples, while IAA appeared only after treatment with exogenous insulin.

Discussion This appears to be a case of autoimmune Type 1 diabetes induced by IFN‐α treatment and developing on a predisposed genetic background with an unusually rapid development of the autoimmune process as reflected by the absence of detectable autoantibodies up to 2.5 months prior to disease onset. In this example of fulminant Type 1 diabetes a pathogenic process unbalanced towards a Th1‐mediated autoimmune response is hypothesized.

Diabet. Med. 18, 329–332 (2001)
Vibration perception threshold testing in patients with diabetic neuropathy: ceiling effects and reliability
Authors: Van Deursen R. W. M. , Sanchez M. M. , Derr J. A. , Becker M. B. , Ulbrecht J. S. , Cavanagh P. R.
Published: March 2003

Aims  To test the reliability of a new vibrometer (Maxivibrometer) which was constructed so that vibration perception threshold (VPT) could be determined without the disadvantage of the off‐scale measurements frequently experienced with the Biothesiometer.

Methods  The two devices were compared and tested on a group of diabetic neuropathic subjects and a group of healthy, matched control subjects. VPT was tested on the plantar surface of the feet.

Results  The Maxivibrometer gave an actual measurement in all cases even if subjects were severely neuropathic. The replication‐to‐replication and day‐to‐day intraclass correlation coefficients for the Maxivibrometer VPT were, except in one case, above 0.94, indicating excellent reliability. The Biothesiometer VPT could also be measured with excellent reliability but only within a limited range of mild to moderate neuropathy, so it appears to be an appropriate screening tool. The replication‐to‐replication intraclass correlation coefficient was 0.93.

Conclusions  Because VPT could be measured over a wide range with the Maxivibrometer, it was demonstrated that loss of sensation in diabetic neuropathy can progress far beyond the maximum VPT value of the Biothesiometer. The wide measurement range and the excellent reliability make the Maxivibrometer a valuable research tool to quantify loss of sensation, particularly in the presence of severe neuropathy and to record changes over time.

Diabet. Med. 18, 469–475 (2001)
The ADKnowl: identifying knowledge deficits in diabetes care
Authors: Speight J. , Bradley C.
Published: March 2003

Aims  To present the ADKnowl measure of diabetes‐related knowledge and evaluate its use in identifying the nature and extent of patient and health professional knowledge deficits.

Method  The ADKnowl was used in a large‐scale study of 789 patients (451 treated with insulin and 338 treated with tablets and/or diet) attending for annual review at one of two hospital out‐patient diabetes clinics

Results  Knowledge deficits were apparent in the patients. For example, 57% did not recognize the inaccuracy of the statement ‘fresh fruit can be eaten freely with little effect on blood glucose levels’. Seventy‐five percent of patients did not know that it is advisable to trim toenails to the shape of the toe. Knowledge deficits were identified for many other areas of diabetes management, e.g. prevention of hypoglycaemia, avoidance of ketoacidosis. Sixteen health professionals at the clinics answered the same items. Contrary to recommendations, 25% of health professionals thought that fresh fruit could be eaten freely. Seventy‐five percent of health professionals did not know the current recommendations for trimming toenails. As expected, HbA1c did correlate with scores from two specific items, while HbA1c did not correlate with summed ADKnowl score.

Conclusions  Patient knowledge deficits were identified. Some specific knowledge deficits among health professionals may be the cause of some patient knowledge deficits. The ADKnowl is a useful tool in assessing both patient and health professional knowledge deficits and is available for use in a context of continuing evaluation.

Diabet. Med. 18, 626–633 (2001)
Diabetic neuropathic cachexia and acute bilateral cataract formation following rapid glycaemic control in a newly diagnosed Type 1 diabetic patient
Authors: Yuen K. C. J. , Day J. L. , Flannagan D. W. , Rayman G.
Published: March 2003

In patients with Type 1 diabetes mellitus (DM), the development of complications within the first few years of diagnosis is very unusual and the development of complications within weeks of commencement of insulin therapy is exceptional. Diabetic neuropathic cachexia, unlike the other more common neuropathies associated with diabetes, is a rare form of peripheral neuropathy characterized by profound weight loss, painful dysaesthesias over the limbs and trunk with spontaneous resolution usually occurring within a year. The morphologically distinct diabetic or metabolic cataract in patients with newly diagnosed Type 1 DM is also a rare complication. We describe the first case of a young man with newly diagnosed Type 1 DM who developed these two rare complications within 3 months of diagnosis and insulin therapy commencement. Rapid development of complications in this patient raises two possibilities, i.e. a probable link between the pathophysiology of these two complications following rapid glycaemic control, and a subset of patients with unusual susceptibility to complications. We re‐emphasize the need for vigilant monitoring of complications in young diabetic patients, even in the first few years of their disease. In particular, young patients with visual impairment should be evaluated carefully for evidence of treatable eye complications.

Diabet. Med. 18, 854–857 (2001)
Amputations and diabetes: a case‐control study
Authors: Trautner C. , Haastert B. , Giani G. , Berger M.
Published: March 2003

Aims Data concerning the relative risk of amputations in diabetic patients compared with the general population are scarce. Therefore, we carried out a case control study to quantify the relationship between diabetes and amputations.

Methods In 20 hospitals in seven German cities and counties we obtained complete lists of non‐traumatic lower limb amputations performed in 1990 and 1991. Controls were selected from patients of the same surgical departments operated on in the same years. We drew a random sample of patients with procedures not likely to be associated with diabetes. Diabetic status was determined from patients’ records in both cases and controls. We calculated age‐ and sex‐specific and, using logistic regression, adjusted odds ratios (OR) and attributable risks.

Results N = 2400, mean age 61.7 (sd 16.3) years. Cases: n = 729; 486 (66.7%) of them had diabetes. Controls: n = 1671; 127 (7.6%) of them had diabetes. Adjusted OR: 18.2 (confidence interval (CI) 14.2–23.6). Adjusted attributable risk among exposed (ARE): 0.95 (CI 0.93–0.96). Adjusted population attributable risk (PAR): 0.62 (CI 0.57–0.66).

Conclusions This study has demonstrated a strong association between the risk of amputation and diabetes. The odds ratios and attributable risks for diabetic individuals are higher in the younger than in the older age groups. Population attributable risks are great. We conclude that the reduction of amputations in the general population will be achieved by improving foot care in people with diabetes.
Automated detection of diabetic retinopathy on digital fundus images
Authors: Sinthanayothin C. , Boyce J. F. , Williamson T. H. , Cook H. L. , Mensah E. , Lal S. , Usher D.
Published: March 2003

Aims The aim was to develop an automated screening system to analyse digital colour retinal images for important features of non‐proliferative diabetic retinopathy (NPDR).

Methods High performance pre‐processing of the colour images was performed. Previously described automated image analysis systems were used to detect major landmarks of the retinal image (optic disc, blood vessels and fovea). Recursive region growing segmentation algorithms combined with the use of a new technique, termed a ‘Moat Operator’, were used to automatically detect features of NPDR. These features included haemorrhages and microaneurysms (HMA), which were treated as one group, and hard exudates as another group. Sensitivity and specificity data were calculated by comparison with an experienced fundoscopist.

Results The algorithm for exudate recognition was applied to 30 retinal images of which 21 contained exudates and nine were without pathology. The sensitivity and specificity for exudate detection were 88.5% and 99.7%, respectively, when compared with the ophthalmologist. HMA were present in 14 retinal images. The algorithm achieved a sensitivity of 77.5% and specificity of 88.7% for detection of HMA.

Conclusions Fully automated computer algorithms were able to detect hard exudates and HMA. This paper presents encouraging results in automatic identification of important features of NPDR.

Diabet. Med. 19, 105–112 (2002)
A chaotic model for tight diabetes control
Authors: Holt T. A.
Published: March 2003

The principles of non‐linear dynamics (‘chaos’) theory may improve our understanding of the difficulties of blood glucose control in diabetes, may lead to alternative control strategies in selected individuals, and might even enlighten the issues involved in automated glucose control for the future. Possible experimental and mathematical methods of identifying chaotic behaviour in glucose profiles are briefly discussed. Advice based on this model is suggested for those aiming at tight blood glucose control.
Clinical characteristics, GAD antibody (GADA) and change of C‐peptide in Korean young age of onset diabetic patients
Authors: Ahn C. W. , Kim H. S. , Nam J. H. , Song Y. D. , Lim S. K. , Kim K. R. , Lee H. C. , Huh K. B.
Published: March 2003

Aims To investigate the association of clinical and immunological markers with diabetes classification in newly diagnosed young diabetic patients at disease onset.

Methods Eighty‐two diabetic patients recruited within 1 year of onset (mean age 23.0 ± 7.1, M:F = 46:36) were divided into three groups, namely: a low fasting C‐peptide (FC) level at baseline group (the low FC group (n = 14, FC < 0.18 nmol/l)), an intermediate FC group (n = 29, 0.18 nmol/l ≤ FC < 0.37 nmol/l), and a high FC group (n = 39, 0.37 nmol/l ≤ FC). Patients were reclassified at follow‐up (mean follow‐up period 3.7 ± 1.4 years) in the same manner as described above into low FC group (n = 31), intermediate FC group (n = 20), and high FC group (n = 31). The clinical characteristics and prevalence of GADA were compared.

Results Patients in the high FC group at baseline had a higher body mass index (BMI), a higher frequency of a family history of diabetes, a higher meal‐stimulated C‐peptide increment, a lower frequency of ketonuria, a lower frequency of history of diabetic ketoacidosis, and a lower frequency of insulin therapy at diagnosis than those in the low and intermediate FC groups at baseline. Insulin secretory capacity, which was represented by fasting C‐peptide, was affected by BMI at diagnosis and the presence of GADA. All the patients of the low FC group on follow‐up were finally classified as having Type 1 diabetes; moreover, the factors that determined the type of diabetes were lower BMI at onset, GADA positivity, insulin therapy, lower fasting C‐peptide level and lower meal‐stimulated C‐peptide increment at initial admission.

Conclusions Our study suggests that follow‐up involving C‐peptide and GADA measurements in combination with clinical characteristics is useful for discriminating between the types of diabetes in these groups.

Diabet. Med. 19, 227–233 (2002)
Heterogeneity in young adult onset diabetes: aetiology alters clinical characteristics
Authors: Owen K. R. , Shepherd M. , Stride A. , Ellard S. , Hattersley A. T.
Published: March 2003

Aims To describe the characteristics of hepatocyte nuclear factor (HNF) 1α mutation carriers diagnosed with diabetes after 25 years and compare them with young‐onset Type 2 diabetic patients (YT2D) diagnosed at the same age.

Subjects and methods We studied 44 (21 male, 23 female) patients with HNF‐1α mutations diagnosed with diabetes at ages 25–45 years and 44 YT2D subjects matched for sex and age of diagnosis.

Results Median age of onset of diabetes was 35 years in both groups. The HNF‐1α group demonstrated: lower body mass index (25.1 vs. 30.7 kg/m2; P < 0.001) and lower fasting triglycerides (1.37 vs. 2.96 mmol/l; P = 0.001) with similar fasting cholesterol level. They had lower glycated haemoglobin A1c (7.3 vs. 8.5%; P = 0.015) despite greater duration of diabetes (24 vs. 16 years; P = 0.02) and less frequent treatment with insulin (21% vs. 55%; P = 0.002). They were less likely to be treated for hypertension (13.3% vs. 56.3%; P = 0.009). Importantly, no difference was observed in reported parental history of diabetes between the two groups (65.9% vs. 63.6%; P = 0.92). Logistic regression showed that triglyceride levels and presence of anti‐hypertensive treatment were the most important independent variables.

Conclusions Patients with HNF‐1α mutations may present with diabetes as young adults between the ages of 25–45 years. In this age range a wide differential diagnosis of diabetes is observed. Conventional criteria of age of onset and family history will not differentiate HNF‐1α mutation carriers from YT2D subjects in this age range, but features of the metabolic syndrome, in particular fasting triglycerides and hypertension, are helpful. In patients diagnosed before 45 years without features of insulin resistance the diagnosis of HNF‐1α should be considered.
Post‐mortem findings in familial partial lipodystrophy, Dunnigan variety
Authors: Haque W. A. , Vuitch F. , Garg A.
Published: March 2003

Aims Familial partial lipodystrophy, Dunnigan variety (FPLD), is an autosomal dominant disorder due to missense mutations in the lamin A/C gene and is characterized by gradual loss of subcutaneous fat from the extremities and trunk, fat accumulation in the head, neck and intra‐abdominal areas, insulin resistance and its metabolic complications. We studied autopsy findings in two patients with FPLD to determine fat distribution and organ involvement.

Results Patient 1, a 66‐year‐old woman with the R482Q mutation, had diabetes mellitus, dyslipidaemia, and coronary artery disease and died suddenly. Autopsy confirmed the typical body fat distribution and further revealed excess fat deposition in the subpectoral regions extending to the axillae, in the axillary lymph nodes and in the retroperitoneum. Atherosclerotic vascular disease including old infarcts of the myocardium, temporal lobe and kidneys were noted. Severe amyloidosis of the pancreatic islets and grouped muscle atrophy of the quadriceps and diaphragmatic muscles were present. Patient 2, a 29‐year‐old woman belonging to a pedigree with the R62G mutation, died of hyperlipidaemia‐induced acute pancreatitis. Autopsy of patient 2 revealed extensive pancreatitis, hepatic steatosis and polycystic ovaries.

Conclusions Our study confirms typical body fat distribution and describes new sites of excess fat deposition. Our data show predisposition to atherosclerosis and polycystic ovaries and suggest that pancreatic amyloidosis may underlie development of hyperglycaemia in FPLD patients.

Diabet. Med. 19, 1022–1025 (2002)
Effect of hormone replacement therapy on inflammation‐sensitive proteins in post‐menopausal women with Type 2 diabetes
Authors: Manning P. J. , Sutherland W. H. F. , Allum A. R. , De Jong S. A. , Jones S. D.
Published: March 2003

Aims To test the effect of oral hormone replacement therapy (HRT) on plasma C‐reactive protein (CRP), soluble vascular cell adhesion molecule‐1 (VCAM‐1), soluble intercellular adhesion molecule‐1 (ICAM‐1) and IL‐6 concentrations and leucocyte count in post‐menopausal women with Type 2 diabetes.

Methods Post‐menopausal women with Type 2 diabetes (n
 
=
 61) were randomized in a double‐blind fashion to receive either continuous combined hormone replacement therapy (n
 
=
 29) with conjugated equine oestrogen (0.625 mg/day) plus medroxyprogesterone acetate (2.5 mg/day) or placebo (n   =  32) for 6 months. Study variables were measured at baseline and at the end of the study.

Results Eight women randomized to hormone replacement therapy and four women assigned to placebo group dropped out of the study. Plasma CRP increased (2.2 mg/l, 95% confidence interval 0.3–4.1 mg/l) significantly (P
 
=
 0.02) in women treated with HRT (n
 
=
 21) compared with placebo (n   =  29) taking baseline CRP, body mass index (BMI) and smoking status into account. Plasma levels of cell adhesion molecules, IL‐6 and leucocyte count did not change significantly during the study.

Conclusions These findings indicate that oral HRT with conjugated equine oestrogen plus medroxyprogesterone acetate increases plasma CRP levels but not necessarily global inflammatory activity in post‐menopausal diabetic women. An increase in plasma CRP may potentially increase risk of a cardiovascular event.
The epidemiology of diabetic limb sepsis: an African perspective
Authors: Abbas Z. G. , Gill G. V. , Archibald L. K.
Published: March 2003

We review the epidemiology of foot and hand sepsis in adult diabetes patients in Africa. Limb sepsis in these patients is associated with significant morbidity and mortality. The pathogenesis of diabetic foot infections in these patient populations appears to be similar to that for patients in industrialized countries —ulcers and underlying peripheral neuropathy being the most important risk factors. Prevention of peripheral neuropathy through aggressive glycaemic control may be the most important primary control measure for foot infections. The tropical diabetic hand syndrome (TDHS) is being increasingly seen in diabetes patients in certain parts of Africa. The syndrome is acute, usually follows minor trauma to the hand, and is associated with a progressive synergistic form of gangrene. The major risk factors for TDHS are unknown but recent data suggest poor glycaemic control is associated with poor outcome. Treatment of TDHS requires aggressive surgery. Hence, preventive efforts for both foot and hand sepsis include aggressive glucose control, and education on hand and foot care and the importance of seeking medical attention promptly at the earliest onset of symptoms.

Diabet. Med. 19, 895–899 (2002)
Preventing glycaemic excursions in diabetic patients requiring percutaneous endoscopic gastrostomy (PEG) feeding after a stroke
Authors: Kerr D. , Hamilton P. , Cavan D. A.
Published: March 2003

Aims and methods Enteral feeding for diabetic patients with a stroke is often associated with hyperglycaemia and/or hypoglycaemia, which can adversely influence neurological recovery. We have developed a structured enteral feeding programme aimed at establishing ‘normal’ feeding patterns and avoiding marked glycaemic excursions.

Results Of 332 consecutive patients admitted to an acute stroke unit, 20 of 41 diabetic patients required PEG feeding. Over the initial 24–48 h, patients had 22‐ h feeds with continuous intravenous infusion of soluble insulin. Thereafter, they were established on three feeds per day. Soluble insulin was given prior to each feed with isophane insulin at 2200 h. Average duration of feed was 13 ± 8 days with an achieved glucose level of 8.7 ± 2.5 (mean ±sd) mmol/l associated with 0.8 episodes of biochemical hypoglycaemia (< 3 mmol/l) each week.

Conclusions A structured enteral feeding programme for PEG‐fed diabetic patients can improve the quality of care with avoidance of marked glycaemic excursions.

Diabet. Med. 19, 1006–1008 (2002)
Prevalence of diabetic eye disease in patients entering a systematic primary care‐based eye screening programme
Authors: Younis N. , Broadbent D. M. , Harding S. P. , Vora J. P.
Published: March 2003

Aims Large‐scale, baseline prevalence measurements in a population at the institution of systematic retinal screening are currently unavailable. We report the prevalence of all grades of retinopathy at entry into a systematic primary care‐based diabetic eye screening programme.

Methods Primary care‐based photographic screening utilizing mydriasis and three‐field non‐stereoscopic photography for all patients with diabetes (except those under continuing care of an ophthalmologist) in Liverpool. Sight‐threatening diabetic eye disease (STED) was defined as any of: moderate preproliferative retinopathy or worse, circinate maculopathy or exudates within one disc diameter of the centre of fovea.

Results Type 1 diabetes mellitus (DM) (n = 831): baseline prevalence (95% confidence interval (CI)) of any retinopathy, proliferative diabetic retinopathy (PDR) and STED was 45.7% (42.3–49.1), 3.7% (2.4–5.0) and 16.4% (13.9–18.9), respectively. Presence of STED was associated with increased disease duration (odds ratio (OR) 1.09 per year; P < 0.0001) and higher in men (OR 2.15; P = 0.001). Type 2 DM (n = 7231): baseline prevalence (95% CI) of any retinopathy, PDR and STED was 25.3% (24.3–26.3), 0.5% (0.3–0.7) and 6.0% (5.5–6.5), respectively. Presence of STED was associated with longer time since diagnosis of DM (OR 1.03; P < 0.0001) and insulin use (OR 2.46; P < 0.0001).

Conclusion This study provides baseline information for health providers on prevalence of all grades of retinopathy and STED in a large population at the establishment of systematic screening. Baseline prevalence of STED was high and highest in patients with a longer disease duration in both Type 1 and Type 2 DM.

Diabet. Med. 19, 1014–1021 (2002)
The relationship between range size and niche breadth: a test using five species ofGammarus(Amphipoda)
Authors: Gaston Kevin J. , Spicer John I.
Published: March 2003

Data for five closely related species of gammarid crustaceans are used to examine interspecific relationships between the breadth of fundamental tolerance or capacity and geographical range size.Gammarus duebeniis, almost without exception, the most tolerant species and that with the best physiological performance. Although there is some limited variation, the remaining species can be ranked broadly in the sequenceG. zaddachi >G. salinus > G. oceanicus > G. locusta. The wide tolerance and high performance ofG. duebeniis associated with the occupation of a wider range of environmental ‘types’ than any other of the species. In terms of geographical range size, the species can be ranked from most to least widespread in the sequenceG. oceanicus >G. duebeni > G. zaddachi > G. salinus > G. locusta. This provides little support for Brown’s hypothesis, or the argument that the more widely distributed species within a taxonomic assemblage also tend to have the widest fundamental niches. However, if marine (G. oceanicusandG. locusta) and estuarine (G. duebeni,G. zaddachi, G. salinus) species are considered separately, then in each case the species with the largest geographical range is also the most tolerant/best performer. In this sense, the jack‐of‐all‐trades is the master‐of‐all, rather than the master‐of‐none.
Small mammal diversity along elevational gradients in the Philippines: an assessment of patterns and hypotheses
Authors: Heaney Lawrence R.
Published: March 2003

1 It is widely accepted that tropical lowland rain forest holds the greatest diversity of organisms, and it is often implied that this general pattern is also true for virtually all individual higher‐level taxa. Standardized elevational transect surveys of non‐flying small mammals (Insectivora and Rodentia) on geologically old, species‐rich islands in the Philippines consistently show maximum diversity and relative abundance in upper montane/lower mossy forest at 1500–2200 m, often exceeding lowland species richness and relative abundance by a factor of three or more.

2 On mountains where maximum elevation exceeds 2000 m, there is a decline in species richness above about 1500–2000 m, yielding a curvilinear pattern of species richness along the elevational gradient. The peak in species richness occurs at the area of transition from montane to mossy forest, which is also the point at which rainfall probably peaks. In parallel with species richness, relative abundance of small mammals in the Philippines also increases from the lowlands to 1500–2200 m, increasing by a factor from two to 10.

3 Twelve hypotheses concerning patterns of diversity along elevational gradients, plus the null hypothesis, are evaluated. The null hypothesis of no variation and the hypotheses that maximum diversity is in the lowlands, that diversity is highest in areas of least perturbation, and that diversity increases with increasing area, are rejected. There is weak or ambiguous support for the hypotheses that diversity is greatest in areas of community interdigitation, that diversity is highest in the area of highest productivity, that diversity is correlated with habitat complexity, and that diversity is correlated with habitat diversity. There is strongest support for the hypotheses that diversity is correlated with annual rainfall, with total abundance of individuals in the community, with food resource diversity, with areas of reduced competition from other organisms, and with areas characterized by high rates of speciation.

4 Causality is difficult to evaluate because many hypotheses make non‐exclusive predictions, they probably represent non‐independent aspects of causal factors (in other words, there is much interaction among the processes highlighted by the various hypotheses), and they represent the range from proximate to ultimate and from descriptive to causal. All the hypotheses probably represent phenomena that exist in nature, but few (or none) represent phenomena found in all taxa. The primary challenge in the future will not be simply to accept or reject individual hypotheses, but rather to determine the circumstances under which the various causal factors are most important, how they interact, and how they can be combined into a more comprehensive and general multi‐factorial model.
Using simple environmental variables to estimate below‐ground productivity in grasslands
Authors: Gill R. A. , Kelly R. H. , Parton W. J. , Day K. A. , Jackson R. B. , Morgan J. A. , Scurlock J. M. O. , Tieszen L. L. , Castle J. V. , Ojima D. S. , Zhang X. S.
Published: March 2003

In many temperate and annual grasslands, above‐ground net primary productivity (NPP) can be estimated by measuring peak above‐ground biomass. Estimates of below‐ground net primary productivity and, consequently, total net primary productivity, are more difficult. We addressed one of the three main objectives of the Global Primary Productivity Data Initiative for grassland systems to develop simple models or algorithms to estimate missing components of total system NPP. Any estimate of below‐ground NPP (BNPP) requires an accounting of total root biomass, the percentage of living biomass and annual turnover of live roots. We derived a relationship using above‐ground peak biomass and mean annual temperature as predictors of below‐ground biomass (r2 = 0.54; P = 0.01). The percentage of live material was 0.6, based on published values. We used three different functions to describe root turnover: constant, a direct function of above‐ground biomass, or as a positive exponential relationship with mean annual temperature. We tested the various models against a large database of global grassland NPP and the constant turnover and direct function models were approximately equally descriptive (r2 = 0.31 and 0.37), while the exponential function had a stronger correlation with the measured values (r2 = 0.40) and had a better fit than the other two models at the productive end of the BNPP gradient. When applied to extensive data we assembled from two grassland sites with reliable estimates of total NPP, the direct function was most effective, especially at lower productivity sites. We provide some caveats for its use in systems that lie at the extremes of the grassland gradient and stress that there are large uncertainties associated with measured and modelled estimates of BNPP.
Net primary productivity mapped for Canada at 1‐km resolution
Authors: Liu J , Chen J. M. , Cihlar J. , Chen W.
Published: March 2003

Aim To map net primary productivity (NPP) over the Canadian landmass at 1‐km resolution.

Location Canada.

Methods A simulation model, the Boreal Ecosystem Productivity Simulator (BEPS), has been developed. The model uses a sunlit and shaded leaf separation strategy and a daily integration scheme in order to implement an instantaneous leaf‐level photosynthesis model over large areas. Two key driving variables, leaf area index (every 10 days) and land cover type (annual), are derived from satellite measurements of the Advanced Very High Resolution Radiometer (AVHRR). Other spatially explicit input data are also prepared, including daily meteorological data (radiation, precipitation, temperature, and humidity), available soil water holding capacity (AWC) and forest biomass. The model outputs are compared with ground plot data to ensure that no significant systematic biases are created.

Results The simulation results show that Canada’s annual net primary production was 1.22 Gt C year−1 in 1994, 78% attributed to forests, mainly the boreal forest, without considering the contribution of the understorey. The NPP averaged over the entire landmass was ~140 g C m−2 year−1 in 1994. Geographically, NPP varied greatly among ecozones and provinces/territories. The seasonality of NPP is characterized by strong summer photosynthesis capacities and a short growing season in northern ecosystems.

Conclusions This study is the first attempt to simulate Canada‐wide NPP with a process‐based model at 1‐km resolution and using a daily step. The statistics of NPP are therefore expected to be more accurate than previous analyses at coarser spatial or temporal resolutions. The use of remote sensing data makes such simulations possible. BEPS is capable of integrating the effects of climate, vegetation, and soil on plant growth at a regional scale. BEPS and its parameterization scheme and products can be a basis for future studies of the carbon cycle in mid‐high latitude ecosystems.
Latitudinal extent and natural history characteristics of birds in Nicaragua
Authors: Gillespie Thomas W.
Published: March 2003

This paper assesses the latitudinal extent of terrestrial breeding birds in Nicaragua. In particular, associations among latitudinal midpoint, body mass, and latitudinal extent are examined; significant differences between natural history characteristics (trophic guild, forest dependence, number of forest types) and latitudinal extent are identified; and a test is undertaken of Rapoport's rule for birds at the edge of their northern or southern range in Nicaragua. Birds in Nicaragua were classified into four categories based on latitudinal extent: birds generally restricted to Central America (20%); birds near the edge of their range within Nicaragua (34%); Neotropical birds (42%); and Pan‐American birds (4%). Latitudinal midpoint had a significant negative correlation with latitudinal extent over different taxonomic scales. Natural history characteristics of trophic guild, forest dependence and number of forest types can account for significant differences in species latitudinal extent. Carnivores had greater latitudinal extents than most other trophic guilds, non‐forest birds had greater latitudinal extents than birds that require patchy forest, and birds that occur in four or more forest types had greater latitudinal extents than birds restricted to one or two forest types. Contrary to Rapoport's rule, birds with a northern affinity or latitudinal midpoint north of Nicaragua had significantly smaller latitudinal extents than birds with a southern affinity or latitudinal midpoint south of Nicaragua. A comparison of natural history characteristics of birds with northern and southern affinities found no difference between trophic guild or forest dependence but a significant difference among the number of forest types used by forest birds. Birds with a southern affinity were restricted to fewer forest types than birds with a northern affinity.
Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro‐ecosystems of Mesoamerica
Authors: Gordon James E. , Barrance Adrian J. , Schreckenberg Kate
Published: March 2003

Aim To test the potential to conserve rare dry forest tree and shrub species circa situm.

Location Oaxaca, Mexico and Southern Honduras.

Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Species’ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.

Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.

Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found.
Identification of a new connexin gene GJA11 (Cx59) using degenerate PCR primers
Authors: Coucke Paul J. , Laer Lut Van , Meyers Johan , Hauwe Peter Van , Ottschytsch Natacha , Wauters Jan G. , Kelley Philip , Willems Patrick J. , Camp Guy Van
Published: March 2003

Introduction Connexins (Cx) comprise a family of homologous proteins that are involved in the intercellular exchange of ions and small metabolites between adjacent cells. So far, mutations in seven different connexins have been found in humans, each resulting in a genetic disease.

Methods Based on the sequence alignment of known human Cx genes, we developed degenerate PCR primers that we anticipated would amplify members of the Cx gene family, in order to identify novel Cx genes.

Results By subcloning and sequencing the PCR products, we identified a previously unidentified connexin gene that we named Cx59 (GJA11). Using FISH we localized the GJA11 gene to chromosome 1p34, and by the analysis of a YAC contig of this region, we mapped this gene within the linkage interval of an Indonesian family with autosomal dominant nonsyndromic hearing loss (ADNSHL). Because mutations in other connexins, namely GJB3 (Cx31) and GJB6 (Cx30), lead to similar forms of ADNSHL, GJA11 (Cx59) was a very strong candidate gene. Therefore, we performed mutation analysis of the coding region of GJA11 in patients of this Indonesian family, but no disease‐causing mutation was found.
Major discoveries on the dermal skeleton of fossil and Recent polypteriforms: a review
Authors: Daget Jacques , Gayet Mireille , Meunier François J , Sire Jean‐Yves
Published: March 2003

Following the discovery of the first living polypterid, Polypterus bichir, in 1802, almost two centuries later we now know of 15 living species (including four subspecies), 14 belonging to the genus Polypterus and one to the genus Erpetoichthys (Calamoichthys) all inhabiting intertropical Africa. The polypterid fossil record was for a long time reduced to some scarce, disarticulated bones, mainly scales, found in various African deposits covering a wider area than the actual geographical distribution. With the discovery, on one hand, of polypterid scales, vertebrae, dermal bones of the cranium and dorsal spiny rays in South America and, on the other hand, of scales and numerous dorsal spiny rays in Niger and Sudan, and two articulated fossils in Morocco, the story of the polypteriforms has revealed some of its mysteries. The discovery of isopedine between dentine and bony basal plate in the scales of living and fossil polypterid species is considered a synapomorphy of the group, and has been an important aid in discriminating polypterid scales from other ganoid scales. A review of the main findings during the last 20 years is presented.
Diadromy, diversity and divergence: implications for speciation processes in fishes
Authors: McDowall R M
Published: March 2003

Ghoti papers

Ghoti aims to serve as a forum for stimulating and pertinent ideas. Ghoti publishes succinct commentary and opinion that addresses important areas in fish and fisheries science. Ghoti contributions will be innovative and have a perspective that may lead to fresh and productive insight of concepts, issues and research agendas. All Ghoti contributions will be selected by the editors and peer reviewed.

Etymology of Ghoti

George Bernard Shaw (1856–1950), polymath, playwright, Nobel prize winner and the most prolific letter writer in history, was an advocate of English spelling reform. He was reportedly fond of pointing out its absurdities by proving that ‘fish’ could be spelt ‘ghoti’. That is: ‘gh’ as in ‘rough’, ‘o’ as in ‘women’ and ‘ti’ as in palatial.

Diadromous migrations can have what seem to be opposing roles in the processes of developing genetic diversity between populations of a species, in terms of morphological and behavioural divergence and speciation. On the one hand, diadromy promotes gene flow among populations, and thereby hinders development of genetic structuring within species and prevents speciation across a species’ broad range. On the other hand, diadromy fosters dispersion and the invasion of new habitats and, when accompanied by the establishment of landlocked/freshwater limited populations, promotes speciation. Examples of both processes can be observed across the diversity of diadromous fishes.
Depensation: evidence, models and implications
Authors: Liermann  , Hilborn
Published: March 2003

We review the evidence supporting depensation, describe models of two depensatory mechanisms and how they can be included in population dynamics models and discuss the implications of depensation. The evidence for depensation can be grouped into four mechanisms: reduced probability of fertilisation, impaired group dynamics, conditioning of the environment and predator saturation. Examples of these mechanisms come from a broad range of species including fishes, arthropods, birds, mammals and plants. Despite the large number of studies supporting depensatory mechanisms, there is very little evidence of depensation that is strong enough to be important in a population’s dynamics. However, because factors such as demographic and environmental variability make depensatory population dynamics difficult to detect, this lack of evidence should not be interpreted as evidence that depensatory dynamics are rare and unimportant. The majority of depensatory models are based on reduced probability of fertilisation and predator saturation. We review the models of these mechanisms and different ways they can be incorporated in population dynamics models. Finally, we discuss how depensation may affect optimal harvesting, pest control and population viability analysis.
Tumours and related lesions of the endocrine system of bony and cartilaginous fishes
Authors: Leatherland  , Down
Published: March 2003

The literature pertaining to the prevalence and histopathology of endocrine cell and tissue tumours and related lesions (TRL) in bony and cartilaginous fishes is catalogued and reviewed in the context of the embryological origin of the various components of the endocrine system. Reports of TRLs of endocrine cells or tissues of fishes are relatively rare, and of these, most describe thyroid neoplasms that appear to be simple hyperplasia. The vast majority of published reports of endocrine TRLs in fishes are case‐studies, and thus, with a few notable exceptions, the aetiology of the lesions is unknown. The exceptions include the epizootics of thyroid neoplasms in introduced Pacific salmon in the Great Lakes, which appear to have an environmental aetiology, and epizootics of gonadal stromal cell neoplasms. The latter were all found in either hybrid species or highly inbred captive strains of fishes, suggesting a genetic involvement in the tumourigenesis. The possible aetiologies for the reported TRLs in wild and captive fish species are discussed, and various hypotheses proposing infectious agents, genetic factors and environmental contaminants are considered.
Cerebral blood flow velocity and perfusion in purulent meningitis: a comparative TCD and 99MTC‐HMPAO‐SPECT study
Authors: Haring H.‐P. , Kampfl A. , Grubwieser G. , Donnemiller E. , Pfausler B. , Schmutzhard E.
Published: March 2003

In 15 patients (median age 33 years; range 17–74 years) suffering from acute pneumococcal (10 cases) and meningococcal (five cases) meningitis, cerebral blood flow velocity (CBFV) was measured in the M1– segment of the middle cerebral artery (MCA) by transcranial Doppler sonography, and cerebral perfusion changes were evaluated by 99m‐Tchexamethylpropylene amine oxime single photon emission computed tomography (HMPAO SPECT). The objective of the study was to test whether increased CBFV during the acute phase of purulent meningitis reflects hyperemia, and to evaluate focal perfusion abnormalities and their correlation to CBFV changes.

In eight patients with marked side‐differences in CBFVs during the acute phase of the disease SPECT scans were normal in five. In three patients unilateral perfusion defects correlated with the side of higher CBFV. In seven patients presenting with symmetrically elevated CBFV, SPECT scans were normal in four and revealed focal abnormalities in the remaining three. Follow up SPECT scans were normal in 14/15 patients.

The results of our study suggest that elevated CBFV in acute bacterial meningitis does not reflect cerebral hyperemia. Focal cerebral perfusion defects occur independently from functional alterations in the cerebral macrovasculature. A causative pathophysiologic relationship of high CBFV and focal perfusion defects cannot be drawn from these data.
Neurophysiological and radiological findings in myotonic dystrophy patients
Authors: Fierro B. , Daniele O. , Aloisio A. , Buffa D. , Bua V. La , Oliveri M. , Manfrè L. , Brighina F.
Published: March 2003

Somatosensory evoked potentials (SEPs) and brainstem auditory evoked potentials (BAEPs) were recorded in 10 patients with myotonic dystrophy and in 20 sex and age‐matched healthy controls. In all patients a brain MRI examination was also performed. In our results, the significantly longer absolute peak latencies of the SEPs and the abnormal increasing of the later components of the BAEPs suggest an involvement of the afferent sensory and central auditory pathways. Brain MRI showed white matter hyperintense lesions (WMHL) in eight patients (80%). No correlations were found between individual abnormal electrophysiological parameters or severity of WMHL and age, age at onset, disease duration or muscular impairment. The total number (SEP + BAEP) of electrophysiological abnormalities significantly correlated with muscular impairment (p < 0.05) and MRI changes (p < 0.05), suggesting a strict pathogenetic linkage between muscular and nervous system alterations in this disease.
Influence of IFN‐β1b (Betaferon) on cytokine mRNA profiles in blood mononuclear cells and plasma levels of soluble VCAM‐1 in multiple sclerosis
Authors: Matusevicius D. , Kivisäkk P. , Navikas V. , Tian W.‐Z. , Söderström M. , Fredrikson S. , Link H.
Published: March 2003

Inflammatory cell infiltration within the central nervous system (CNS) and upregulation of both pro‐ and anti‐inflammatory cytokines are characteristic for multiple sclerosis (MS). Treatment with interferon‐β1b (IFN‐β1b) reduces the number and severity of MS relapses. To examine whether treatment with IFN‐β1b affects levels of cytokine mRNA expressing blood mononuclear cells (MNC) we employed in‐sit hybridization with synthetic oligonucleotide probes to detect and enumerate IFN‐γ, TNF‐α, IL‐10, TGF‐β and perforin mRNA expressing cells in MS patients before treatment with IFN‐β1b and during tretmetn for 3–6 weeks and for 3–6 monts. Numbers of blood MNC spontaneously expressing TNF‐α and IL‐10 mRNA were lower after 3–6 months of treatment, while numbers of IFN‐γ, TGF‐β and perforin mRNA expressing MNC were not affected by treatment. IFN‐β1b had no influence on levels of MBP‐reactive IFN‐γ, TNF‐α, TGF‐β, IL‐10 or perforin mRNA expressing blood MNC determined after 3–6 weeks 3–6 months of treatment. Parallel measurements of plasma concentrations of soluble vascular cell adhesion molecule‐1 (sVCAM‐1) revealed elevated levels after 3–6 weeks of treatment and these levels remained higher after 3–6 months of treatment. The results suggest that IFN‐β1b treatment upregulates plasma levels of sVCAM‐1, but has little effects on numbers of blood MNC expressing mRNA of the pro‐ and anti‐inflammatory cytokines under study.