The clinical variability of maternally inherited diabetes and deafness is associated with the degree of heteroplasmy in blood leukocytes

CONTEXT

Maternally inherited diabetes and deafness (MIDD) is a rare form of diabetes with a matrilineal transmission, sensorineural hearing loss, and macular pattern dystrophy due to an A to G transition at position 3243 of mitochondrial DNA (mtDNA) (m.3243A>G). The phenotypic heterogeneity of MIDD may be the consequence of different levels of mutated mtDNA among mitochondria in a given tissue.

OBJECTIVE

The aim of the present study was thus to ascertain the correlation between the severity of the phenotype in patients with MIDD and the level of heteroplasmy in the blood leukocytes.

PARTICIPANTS

The GEDIAM prospective multicenter register was initiated in 1995. Eighty-nine Europid patients from this register, with MIDD and the mtDNA 3243A>G mutation, were included. Patients with MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes) or with mitochondrial diabetes related to other mutations or to deletions of mtDNA were excluded.

RESULTS

A significant negative correlation was found between levels of heteroplasmy and age of the patients at the time of sampling for molecular analysis, age at the diagnosis of diabetes, and body mass index. After adjustment for age at sampling for molecular study and gender, the correlation between heteroplasmy levels and age at the diagnosis of diabetes was no more significant. The two other correlations remained significant. A significant positive correlation between levels of heteroplasmy and HbA(1c) was also found and remained significant after adjustment for age at molecular sampling and gender.

CONCLUSIONS

These results support the hypothesis that heteroplasmy levels are at least one of the determinants of the severity of the phenotype in MIDD.

Positron emission tomography/computed tomography introduction in the clinical management of patients with suspected recurrence of ovarian cancer: a cost-effectiveness analysis

Aim of this study was to evaluate the economic impact of the introduction of positron emission tomography/computed tomography (PET/CT) in the early detection of recurrent ovarian cancer through a cost-effectiveness analysis of different diagnostic strategies. Thirty-two consecutive patients with suspected ovarian cancer recurrence, studied by both contrast enhanced abdominal CT and PET/CT, were retrospectively included in the study. Three different diagnostic strategies were evaluated and compared: (1) CT only or baseline strategy; (2) PET/CT for negative CT or strategy A; (3) PET/CT for All or strategy B. For each one, expected costs, avoided surgery and incremental cost-effectiveness ratio (ICER) were calculated to identify the most cost-effective strategy. The number of positive patients increased from baseline strategy (20/32) to strategy A and B (30/32 and 29/32 respectively). Positron emission tomography/computed tomography reoriented physician choice in 31% and 62% of patients (strategies A and B respectively). Strategy A is dominated by strategy B, which is more expensive (2909 euro vs. 2958 euro), but also more effective (3 cases of surgery avoided) and presents an ICER of 226.77 euro per surgery avoided (range: 49.50-433.00 euro). Positron emission tomography/computed tomography introduction in this population is cost-effective and allowed to redirect the clinical management of patients towards more appropriate therapeutic choices.

Insulin glargine provides greater improvements in glycaemic control vs. intensifying lifestyle management for people with type 2 diabetes treated with OADs and 7-8% A1c levels. The TULIP study

AIM

To determine whether earlier administration of insulin glargine (glargine) vs. the intensification of lifestyle management (LM) improves glycaemic control in type 2 diabetes patients with A1c 7-8% treated with oral therapy.

METHODS

TULIP [Testing the Usefulness of gLargine when Initiated Promptly in type 2 diabetes mellitus (T2DM)] was a 9-month, 12-visit, open-label, multinational, multicentre, randomized study to evaluate starting glargine or intensifying LM in T2DM patients aged 40-75 years, body mass index (BMI) 24-35 kg/m2 and A1c 7-8%, treated with maximum doses of metformin and sulphonylurea for > or = 2 years. Glargine was injected once daily (evening) and titrated to fasting blood glucose 0.7-1.0 g/l. In the LM arm, dietary and physical activity counselling recommended stable weight for people with BMI < 27 kg/m2 or weight loss of 3 kg for patients with BMI > or = 27 kg/m2. A total of 215 patients were randomized to glargine (n = 106) or LM (n = 109). The primary objective was patients achieving A1c < 7% at endpoint. Secondary endpoints included changes in A1c, in fasting plasma glucose (FPG), body weight and hypoglycaemia incidence.

RESULTS

Two hundred and eleven (52.6% male) patients were randomized and treated; mean (+/- s.d.) age 60.7 +/- 7.9 years, weight 84.5 +/- 13.1 kg, BMI 29.9 +/- 3.5 kg/m2 and A1c 7.6 +/- 0.4%. More patients reached A1c < 7% (66 vs. 38%; p < 0.0001) or < 6.5% (34 vs. 11%; p = 0.0001) with glargine vs. LM. The change in FPG from baseline to study endpoint was significantly greater in the glargine vs. the LM arm (-0.50 +/- 0.47 vs. -0.05 +/- 0.39 g/l respectively; p < 0.0001). Compared with the glargine group, the LM group showed a decrease in weight (+0.9 +/- 2.9 vs. -2.5 +/- 3.2 kg; p < 0.0001), as well as the expected lower symptomatic hypoglycaemia (55.3 vs. 25.0%; p < 0.0001) and nocturnal hypoglycaemia (20.4 vs. 5.6%; p = 0.0016). No significant changes were observed from baseline to study endpoint in any of the lipid parameters tested.

CONCLUSIONS

In patients with T2DM with A1c 7-8%, who were previously treated by conventional LM and OAD therapy, adding glargine resulted in greater improvements in glycaemic control vs. intensifying LM.

Incidence and characteristics of lower limb amputations in people with diabetes

AIMS

To estimate the incidence, characteristics and potential causes of lower limb amputations in France.

METHODS

Admissions with lower limb amputations were extracted from the 2003 French national hospital discharge database, which includes major diagnoses and procedures performed during hospital admissions. For each patient, diabetes was defined by its record in at least one admission with or without lower limb amputation in the 2002-2003 databases.

RESULTS

In 2003, 17 551 admissions with lower limb amputation were recorded, involving 15 353 persons, which included 7955 people with diabetes. The crude incidence of lower limb amputation in people with diabetes was 378/100 000 (349/100 000 when excluding traumatic lower limb amputation). The sex and age standardized incidence was 12 times higher in people with than without diabetes (158 vs. 13/100 000). Renal complications and peripheral arterial disease and/or neuropathy were reported in, respectively, 30% and 95% of people with diabetes with lower limb amputation. Traumatic causes (excluding foot contusion) and bone diseases (excluding foot osteomyelitis) were reported in, respectively, 3% and 6% of people with diabetes and lower limb amputation, and were 5 and 13 times more frequent than in people without diabetes.

CONCLUSIONS

We provide a first national estimate of lower limb amputation in France. We highlight its major impact on people with diabetes and its close relationship with peripheral arterial disease/neuropathy and renal complications in the national hospital discharge database. We do not suggest the exclusion of traumatic causes when studying the epidemiology of lower limb amputation related to diabetes, as diabetes may contribute to amputation even when the first cause appears to be traumatic.

Retinal and renal complications in patients with a mutation of mitochondrial DNA at position 3,243 (maternally inherited diabetes and deafness). A case-control study

AIMS/HYPOTHESIS

We assessed the prevalence and determinants of retinal and renal complications in patients with maternally inherited diabetes and deafness (MIDD).

METHODS

This was a multicentre prospective study comparing the prevalence of retinopathy and renal disease in 74 patients with MIDD and 134 control patients matched for sex, age and clinical presentation at onset of diabetes, duration of diabetes and current treatment. Comparisons were adjusted for HbA(1c) and hypertension.

RESULTS

In MIDD patients, HbA(1c) (7.6 +/- 1.6 vs 8.5 +/- 2.0%, p < 0.002), systolic blood pressure (126.6 +/- 16.2 vs 133.1 +/- 17.3 mmHg, p < 0.007) and prevalence of hypertension (33.8 vs 64.2%, p < 0.0001) were lower than in control patients. Prevalence of diabetic retinopathy was 3.7-fold lower in MIDD patients (6/74, 8 vs 40/134, 29.6%, p < 0.0001). Differences between groups remained significant after adjustment for hypertension, systolic blood pressure and HbA(1c). In MIDD, urinary albumin excretion (314.8 vs 80.1 mg/24 h, p = 0.035) and creatinine plasma levels (103.5 vs 82.2 micromol/l, p = 0.0178) were higher and GFR was lower. Impaired renal function (GFR <60 ml/min) was four- to sixfold more frequent in MIDD. Differences between MIDD and control diabetic patients further increased when adjusted for HbA(1c) and systolic blood pressure (p < 0.0001). Adjustment for treatment with an ACE inhibitor or angiotensin II receptor antagonist did not modify the results.

CONCLUSIONS/INTERPRETATION

This study indicates that diabetic retinopathy is less prevalent in MIDD than in control diabetes. This suggests that retinal alterations due to mitochondrial disease may have a protective role. By contrast, nephropathy is far more frequent in MIDD, suggesting the presence of a specific renal disease independent of diabetic nephropathy.

The crack tip: a nanolab for studying confined liquids

We study the equilibrium properties of a liquid phase condensed at the nanoscale between the surfaces of a sharp crack in fused silica in a moist controlled atmosphere. The extension of the condensed phase along the fracture is measured by in situ atomic force microscopy phase imaging and it is shown to be determined by a critical distance between the opposite crack surfaces, which is an increasing function of humidity. The present technique is very promising for measuring the properties of confined liquids at the nanoscale as well as for modeling the physics and chemistry of slow crack propagation in glasses.

Insulin therapy for type 2 diabetes: premixed or basal-prandial?

It is logical to begin type 2 insulin therapy with an injection of an intermediate-acting or a long-acting insulin at bedtime, but one should treat to target, i.e. aim at fasting glycaemias lower than 1.20 g/l to obtain an HbA(1c) close to 7%. Nevertheless, basal insulin therapy does not prevent progression to insulin-secretory deficiency. If necessary, recourse should be made to multiple-injection protocols, taking into account postprandial hyperglycaemia. For every level of HbA(1c), the suppression of postprandial hyperglycaemia, 1 point of HbA(1c) can be gained in theory, whereas reducing the fasting glycaemia to values of less than 1.10 g/l reduces HbA(1c) to close to 7%, whatever the initial level of HbA(1c). However, when a diabetic is clearly not controlled, the preprandial acting use of rapid analogues allows the fasting glycaemia to be improved significantly. Inversely, an early treatment with basal insulin, by correcting glucotoxicity, can also decrease postprandial hyperglycaemia. Many industry-sponsored studies comparing insulin therapy regimens show annoying biased interpretations of results. It does not seem pertinent to compare a single injection with two or even three injections, nor to compare an efficient titration with an inefficient titration or to eliminate oral drugs, in particular sulphonylureas combined with a basal insulin. If premix insulins can give satisfactory results in patients who maintain a sufficient residual insulin-secretion, we think it would be preferable to adopt the basal-prandial regimen and a step-by-step escalating therapy. The first stage consists in combining oral therapy with an injection of NPH insulin or a long-acting analogue at bedtime, aiming at a fasting glycaemia of less than 1.20 g/l. In the next stages, a single injection of rapid-acting insulin analogue is added each time. The main advantage of this regimen is to fix a target adapted to each injection and, as a result, to facilitate forced titration of the doses.

Cost-effectiveness analysis in the clinical management of patients with known or suspected lung cancer: [18F]fluorodeoxyglucose PET and CT comparison

AIM

The aim of this study was to evaluate the economic impact of the introduction of positron emission tomography (PET) in the clinical management of patients with known or suspected lung cancer through a cost-effectiveness analysis of different diagnostic strategies.

METHODS

In Italy, 75 patients with known or suspected lung cancer were included in the study. Three different diagnostic strategies were compared: 1) baseline or traditional strategy, i.e. computed tomography (CT) alone; 2) strategy A, i.e. PET for indefinite CT; 3) strategy B, i.e. PET for all. For each strategy expected costs and life expectancy, as measured by life year saved (LYS), were evaluated. Incremental cost-effectiveness ratio (ICER) was calculated to identify the most effective strategy.

RESULTS

Compared to the baseline strategy, the introduction of PET changed the clinical management in 40% of cases in strategy A and in 51% of cases in strategy B, with an optimization of the clinical management. Costs of strategy A (2735.42 Euro) and strategy B (2984.52 Euro) were, respectively, 8% and 18% higher than the baseline strategy (2534.81 Euro). LYS was 2.04 and 2.64 for strategy A and B, which were, respectively, 4% and 35% higher than the baseline strategy (1.96 LYS). The ICERs were 2507.63 Euro/LYS and 415.17 Euro/LYS for strategy A and B, respectively. Strategy A is dominated by strategy B, which is more expensive, but also more effective.

CONCLUSION

In Italy, the introduction of PET in the clinical management of all patients with known or suspected lung cancer previously evaluated with CT is cost-effective and allows to gain 2.64 life years at an annual cost of about 415 Euro.

Unexpected similarity of intestinal sugar absorption by SGLT1 and apical GLUT2 in an insect (Aphidius ervi,Hymenoptera) and mammals

Sugars are critical substrates for insect metabolism, but little is known about the transporters and epithelial routes that ensure their constant supply from dietary resources. We have characterized glucose and fructose uptakes across the apical and basolateral membranes of the isolated larval midgut of the aphid parasitoid Aphidius ervi. The uptake of radiolabeled glucose at the basal side of the epithelium was almost suppressed by 200 μM cytochalasin B, uninhibited by phlorizin, and showed the following decreasing rank of specificity for the tested substrates: glucose > glucosamine > fructose, with no recognition of galactose. These functional properties well agree with the expression of GLUT2-like transporters in this membrane. When the apical surface of the epithelium was also exposed to the labeled medium, a cation-dependent glucose uptake, inhibited by 10 μM phlorizin and by an excess of galactose, was detected suggesting the presence in the apical membrane of a cation-dependent cotransporter. Radiolabeled fructose uptakes were only partially inhibited by cytochalasin B. SGLT1-like and GLUT5-like transporters were detected in the apical membranes of the epithelial cell by immunocytochemical experiments. These results, along with the presence of GLUT2-like transporters both in the apical and basolateral cell membranes of the midgut, as we recently demonstrated, allow us to conclude that the model for sugar transepithelial transport in A. ervi midgut appears to be unexpectedly similar to that recently proposed for sugar intestinal absorption in mammals.

Comparison of dinner with bedtime administration of insulin glargine in type 1 diabetic patients treated with basal-bolus regimen

OBJECTIVE

To establish the equivalence in efficacy (HbA(1c)) of insulin glargine injected at dinner versus bedtime in a large number of patients with type 1 diabetes using a fast-acting analogue (FAA) or regular human insulin (RHI) as prandial insulin in an insulin glargine-bolus regimen.

RESEARCH DESIGN AND METHODS

In a 26-week trial, 1178 patients with type 1 diabetes and treated with different basal-bolus regimens were randomized to receive insulin glargine once daily at dinner (n=589) or at bedtime (n=589) while continuing their previous prandial insulin (FAA: 75%; RHI: 25% of patients). The primary objective was to demonstrate equivalence in terms of HbA(1c) levels at endpoint.

RESULTS

Baseline characteristics were similar in the two groups. At endpoint, HbA(1c) (mean+/-standard deviation [S.D.]) had decreased by 0.25+/-0.66% to 7.77+/-0.96% in the dinnertime group (P<0.0001), and by 0.24+/-0.76% to 7.83+/-1.07% in the bedtime group (P<0.0001). The HbA(1c) difference between dinner and bedtime was -0.022% (two-sided 90% confidence interval [CI] -0.09; 0.05), demonstrating statistical equivalence of HbA(1c) at endpoint between the two groups. Equivalence was also demonstrated within prandial groups: HbA(1c) difference between dinner and bedtime was -0.03% (two-sided 90% CI: -0.11; 0.06) for FAAs and -0.04% (two-sided 90% CI: -0.19; 0.11) for RHIs. The incidence of severe hypoglycaemia did not differ between the treatment groups.

CONCLUSION

These data confirm that insulin glargine in combination with either FAA or RHI is equally effective and safe, whether it is administered at dinner or bedtime.

Growth Factors and Chemokines: A Comparative Functional Approach Between Invertebrates and Vertebrates

Growth factors and cytokines control and coordinate a broad spectrum of fundamental cellular functions, and are evolutionarily conserved both in vertebrates and invertebrates. In this review, we focus our attention on the functional phylogenetic aspects of growth factors/cytokines like the Transforming Growth Factor-beta (TGF-beta), the Connective Tissue Growth Factor (CTGF), and the Vascular Endothelial Growth Factor (VEGF). We will also delve into the activites of two chemokine families, interleukin (IL)-8 (or CXCL8) and CC chemokine ligand 2/monocyte chemoattractant protein-1 (CCL2). These molecules have been selected for their involvement in immune responses and wound healing processes, where they mediate and finely regulate various regeneration processes like angiogenesis or fibroplasia, not only in vertebrates, but also in invertebrates.

Hematopoietic cell formation in leech wound healing

The angiogenic process in vertebrates and hirudineans has been compared. The leech Hirudo medicinalis, subjected to an angiogenic stimulus (surgical explant or cytokine treatment) responds, as a vertebrate, with the formation of an extensive network of new vessels accompanied by the production of circulating cells. The reviewed data confirm the surprising similarity between hirudinean and vertebrate processes in wound healing, and suggest that basic common events such as antigenic expressions of endothelial and hemopoietic cells, cytokine secretion and regulation as well as extracellular matrix interactions, are conserved and extended across diverse species, tissues and developmental phases.

Should diabetic patients be asked to test their blood glucose 90 to 120 minutes after the beginning of their meals?

There are three distinct objectives in reducing the post-prandial blood glucose peaks: 1st to reduce the risk of foetal macrosomia in pregnancy, 2nd to reduce cardiovascular morbi-mortality, 3rd to lower the HbA1c. With 6-7 glycaemic controls per day and fractionning their meals, motivated women with gestational diabetes reach this goal. But there is no data today directly proving that post-prandial glycaemia is specifically related to the development of micro and macrovascular complications. So to reduce the cardiovascular risk, there are more arguments in favour of lowering HbA1c or prescribing statins than in prescribing a hypoglycaemic drug acting selectively on post-prandial glycaemia. Lastly, to reduce HbA1c near to the goal of 7%, the most important is to reduce the preprandial glycaemia below 1.20 g/l. The patients must be required to monitor their post-prandial glycaemia 2 hours after the beginning of the meal only when the aim is to lower the HbA1c below 7% or 6.5%, for example during pregnancy, or in case of discrepancy between glycaemia at 8 a.m. and 7 p.m. (below 1.20 g/)l and HbA1c (above 7%). In other cases, in type 2 diabetes, two glycaemias per day, fasting and vesperal, seems sufficient.

Structure and function of the extraembryonic membrane persisting around the larvae of the parasitoid Toxoneuron nigriceps

The embryo of Toxoneuron nigriceps (Hymenoptera, Braconidae) is surrounded by an extraembryonic membrane, which, at hatching, releases teratocytes and gives rise to a cell layer embedding the body of the 1st instar larva. This cell layer was studied at different developmental times, from soon after hatching up to the first larval moult, in order to elucidate its ultrastructural, immunocytochemical and physiological function. The persisting "larval serosa" shows a striking structural and functional complexity: it is a multifunctional barrier with protective properties, limits the passage of macromolecules and it is actively involved in the enzymatic processing and uptake of nutrients. The reported results emphasizes the important role that the embryo-derived host regulation factors may have in parasitism success in Hymenoptera koinobionts.

Screening of Lactobacillus spp. and Pediococcus spp. for glycosidase activities that are important in oenology

AIMS

To assess glycosidase activities from a range of Lactobacillus and Pediococcus species and characterize these activities under conditions pertinent to the wine industry.

METHODS AND RESULTS

Lactic acid bacteria were cultured in MRS broth supplemented with apple juice before being harvested, washed and assayed for glycosidase activity using p-nitrophenol-linked substrates. All strains exhibited a detectable capacity for the hydrolysis of the beta- and alpha-d-glucopyranosides. The magnitude of these activities and their response to the physico-chemical parameters investigated varied in a strain-dependent manner. The use of an assay buffer with a pH below 4 generally resulted in a reduced hydrolysis of both substrates while temperature optima ranged between 35 and 45 degrees C. The effect of the inclusion of ethanol in the assay buffer (up to 12%, v/v) ranged from near complete inhibition to increases in activity approaching 80%. With the clear exception of a single strain, glucose and fructose (0.1-20 g l(-1)) acted as inhibitors. An assessment of glycosidase activity during simultaneous exposure to glucose and ethanol at a pH of 3.5 suggested that ethanol decreased loss of activity under these wine-like conditions.

CONCLUSIONS

Lactobacillus spp. and Pediococcus spp. possess varying degrees of beta- and alpha-d-glucopyranosidase activities, which in turn are influenced differently by exposure to ethanol and/or sugars, temperature and pH. Several strains appeared suited for further evaluation under winemaking conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work highlights the fact that strains of Lactobacillus and Pediococcus have the potential to influence the glycoside composition of wine. Tailoring of wine may therefore be possible through selective application of strains or enzymatic extracts thereof.

Limitations of the so-called "intensified" insulin therapy in type 1 diabetes mellitus

Intensive insulin treatment is defined by basal-prandial insulin therapy which tries to reproduce physiological insulin secretion. This requires 3 to 5 injections and self-monitoring of blood glucose 4 to 5 times a day. Patients who accept their disease and the demanding treatment regimen most often achieve HbA1(c) < 7.5%. Severe complications of diabetes can be avoided without increasing the risk of severe hypoglycemia. However, 50% of type 1 diabetic patients do not reach this objective. The reasons are: the disease itself, the diabetic patient, or the physician. Brittle diabetes with severe, repeated episodes of hypoglycemia and inversely persistent postprandial hyperglycemia prevents patients from reaching the ideal glycemic target. More often, the main obstacle is related to psychological problems: difficulties in self-regulation, denial of the disease, or phobia of hypoglycemia with avoidance behavior. Frequently, young women present eating disorders which can explain the poor diabetes control. The physician himself may be implicated in these poor glycemic results by not prescribing the right tools to obtain optimal glycemic control (staying with just two daily injections with premixed insulin) or by assigning glycemic targets inaccessible for the patient, or when an empathic relationship cannot be established between the patient and the physician. Patient empowerment is the key to the success of functional insulin treatment.