Reduced postprandial GLP-1 responses in women with gestational diabetes mellitus

AIM

We investigated postprandial glucagon-like peptide-1 (GLP-1) responses in pregnant women with and without gestational diabetes mellitus (GDM) and again following delivery when normal glucose tolerance (NGT) was re-established.

METHODS

Eleven women with GDM [plasma glucose (PG) concentration at 120 min after a 75-g oral glucose tolerance test (OGTT): 10.0 ± 0.9 mM (mean ± SD); age: 31 ± 6 years; body mass index (BMI): 31.6 ± 6.4 kg/m(2) ; haemoglobin A1c (HbA1c): 5.6 ± 0.5%] and eight pregnant women with NGT (PG(120 min), OGTT : 5.7 ± 0.7 mM; age: 28 ± 3 years; BMI: 29.7 ± 5.4 kg/m(2) ; HbA1c: 5.4 ± 0.3%) were investigated with a 4-h liquid meal test during third trimester (TT) and 3-4 months postpartum (PP). All patients with GDM re-established NGT following delivery.

RESULTS

Pregnancy was associated with low postprandial GLP-1 responses. Patients with GDM exhibited reduced postprandial GLP-1 responses compared to their PP levels [area under curve (AUC): 5.5 ± 1.3 vs. 8.4 ± 3.2 nM × min, p=0.005], but the difference among NGT women (7.3 ± 2.8 vs. 8.8 ± 2.0 nM × min, p=0.066) was not statistically significant. Pregnancy did not influence postprandial responses of the other incretin hormone glucose-dependent insulinotropic polypeptide (GIP) in any of the groups, but GDM patients were characterized by greater postprandial GIP responses during both TT and PP compared to NGT subjects.

CONCLUSIONS

Pregnancy is associated with reduced postprandial GLP-1 responses (most pronounced in patients with GDM) that normalize after delivery. In contrast, postprandial GIP responses seem unaffected by pregnancy but is increased in GDM patients.

Benzene-poly-carboxylic acids complex with Cis-diammineplatinum (II) dichloride (BP-C1), a novel anticancer agent, induces apoptosis in human breast cancer cells through caspase activation

e12029

Background: Breast cancer is the most frequent malignancy in women in western countries and despite progress in the treatment options surgery, radiation, chemotherapy and hormonal therapy it is still the leading cause of cancer death. BP-C1 is a novel anti-cancer complex of benzol-polycarbonic acids with ammonium-platinum salt developed by Meabco ltd, Denmark. Methods: In the present study, the effect of BP-C1 on growth of human breast cancer cells, MCF7 and T47D, was studied. Cells were exposed to different doses of BP-C1, 100-1000 µg/ml, and cell viability, toxicity (LDH release), cell cycle, apoptosis, caspase activation and gene expression were examined. Results: No toxicity was observed. Exposure of the cells to BP-C1 for 48h, significantly (P<0.001) reduced cell viability by approxematly 90% with IC50 of 400 µg/ml. In cell cycle studies cells were accumulated in sub-G1 phase, which may indicate induction of apoptosis. Annexin 5 assay demonstrated that BP-C1 induces apoptosis of MCF-7 and T47D cell by 65% and 34%, respectively, after 48h of treatment. Detection of caspases by western blot analysis revealed that BP-C1 activates caspase 8 and caspase 9. Moreover, gene expression experiments following BP-C1 treatment and using the Applied Biosystems TaqMan Array Plates indicated that BP-C1 caused an increase in the the expression of pro-apoptotic genes; CASP8AP2, TNFRSF21, RELB, NFKB2, BIRC8 and FADD when compared to the expression level of the House keeping genes, HPRT1 and GAPDH. On the other hand, lower levels of mRNA transcripts of the inhibitory apoptotic genes; BCL2L2 and XIAP were detected. Conclusions: These results may indicate that BP-C1 reduced cell viability of human cancer cells by a unigue induction of apoptosis through activation of the extrinsic (death receptors) and the intrinsic (mitochondrion) apoptotic pathways. These findings may lead to the development of new therapeutic strategies for treatment of cancer using BP-C1 or analogs.

Prevalence of hepatitis B & hepatitis C virus infections in potential blood donors in rural Vietnam

BACKGROUND & OBJECTIVES

Safe blood and blood products should be offered to all patients in need for blood transfusion. The objectives of the present study were to establish prevalence estimates for hepatitis B and hepatitis C virus infections as a foundation for safe blood transfusion in rural Vietnam, and to check the accuracy of the laboratory analysis used for hepatitis testing of blood donors in Vietnam.

METHODS

A cross-sectional study was conducted in two rural communities in Quang Tri, Vietnam. A total of 1,200 blood samples collected from potential blood donors were tested by an enzyme immunoassay technique (EIA) for detection of hepatitis surface antigen (HBsAg), antibodies to hepatitis B core antigen (anti-HBc), and antibodies to hepatitis C antigen (anti-HCV). The EIA test outcome was validated by a chemiluminescent micro particle immunoassay technique (CMIA).

RESULTS

The prevalence of HBsAg and anti-HBc in the study population was 11.4 per cent (95% CI 9.6 - 13.2) and 51.7 per cent (95% CI 48.8 - 54.5), respectively, the prevalences being higher in males than females. The prevalence of anti-HCV was 0.17 per cent. The test agreement between the EIA and CMIA techniques was high both for HBsAg detection (κ = 0.91; 95% CI: 0.83 - 0.99) and for anti-HBc detection (κ = 0.89; 95% CI 0.81 - 0.97). Compared to CMIA results, the positive and negative predictive values of the EIA tests were found to be 94.9 per cent (95% CI 87.5 - 98.6) and 97.5 per cent (95% CI 86.8 - 99.9) for HBsAg, and 92.4 per cent (95% CI 84.2 - 97.2) and 100 per cent (95% CI 91.2 - 100) for anti-HBc.

INTERPRETATION & CONCLUSIONS

The study shows that hepatitis B virus infection is endemic in rural areas of Vietnam and that almost half of the population is or has been infected. Hepatitis C infection is rare, but false negative test results cannot be ruled out. Also, the results indicate that the EIA performance in blood donor screening in Vietnam may be sub-optimal, missing 2.5 per cent of hepatitis B virus carriers and falsely excluding more than 7 per cent of blood donors. As the prevalence of hepatitis B infection is high, occult hepatitis B infection may represent a threat to safe blood transfusion. Therefore, nucleic acid amplification testing for HBV should be considered for blood donor screening in Vietnam.

The influence of age and aerobic fitness: effects on mitochondrial respiration in skeletal muscle

AIM

Mitochondrial function has previously been studied in ageing, but never in humans matched for maximal oxygen uptake ((V)·O2max). Furthermore, the influence of ageing on mitochondrial substrate sensitivity is not known.

METHODS

Skeletal muscle mitochondrial respiratory capacity and mitochondrial substrate sensitivity were measured by respirometry in young (23 ± 3 years) and middle-aged (53 ± 3 years) male subjects with similar (V)·O2max. Protocols for respirometry included titration of substrates for complex I (glutamate), complex II (succinate) and both (octanoyl carnitine) for calculation of substrate sensitivity (C(50) ). Myosin heavy chain (MHC) isoforms, citrate synthase (CS) and β-hydroxy-acyl-CoA-dehydrogenase (HAD) activity, mitochondrial DNA (mtDNA) content, protein levels of complexes I-V and antioxidant defence system [manganese superoxide dismutase (MnSOD)] were measured.

RESULTS

No differences were found in maximal mitochondrial respiration or C(50) with glutamate (2.0 ± 0.3 and 1.8 ± 0.3 mm), succinate (3.7 ± 0.2 and 3.8 ± 0.4 mm) or octanoyl carnitine (47 ± 8 and 56 ± 7 μm) in young and middle-aged subjects respectively. Normalizing mitochondrial respiration to mtDNA young subjects had a higher (P < 0.05) respiratory capacity per mitochondrion compared to middle-aged subjects. HAD activity and mtDNA per mg tissue were higher in middle-aged compared to young subjects. Middle-aged had a higher MHC I isoform and a lower MHC IIX isoform content compared to young subjects.

CONCLUSION

Mitochondrial substrate sensitivity is not affected by ageing. When young and middle-aged men are carefully matched for (V)·O2max, mitochondrial respiratory capacity is also similar. However, per mitochondrion respiratory capacity was lower in middle-aged compared to young subjects. Thus, when matched for (V)·O2max, middle-aged seem to require a higher mitochondrial content than young subjects.

Study of possible combined toxic effects of azaspiracid-1 and okadaic acid in mice via the oral route

Toxins from the okadaic acid (OA) and azaspiracid (AZA) group cause considerable negative health effects in consumers when present in shellfish above certain levels. The main symptoms, dominated by diarrhoea, are caused by damage to the gastrointestinal (GI) tract. Even though OA and AZAs exert toxicity via different mechanisms, it is important to find out whether they may enhance the health effects if present together since they act on the same organs and are regulated individually. In this study, the main issue was the possibility of enhanced lethality in mice upon combined oral exposure to OA and AZA1. In addition, pathological effects in several organs and effects on absorption from the GI tract were studied. Although the number of mice was small due to low availability of AZA1, the results indicate no additive or synergistic effect on lethality when AZA1 and OA were given together. Similar lack of increased toxicity was observed concerning pathological effects that were restricted to the GI-tract. OA and AZA1 were absorbed from the GI-tract to a very low degree, and when given together, uptake was reduced. Taken together, these results indicate that the present practice of regulating toxins from the OA and AZA group individually does not present an unwanted increased risk for consumers of shellfish.

Skeletal muscle mitochondrial respiration in AMPKα2 kinase-dead mice

AIM

To study whether the phenotypical characteristics (exercise intolerance; reduced spontaneous activity) of the AMPKα2 kinase-dead (KD) mice can be explained by a reduced mitochondrial respiratory flux rates (JO(2) ) in skeletal muscle. Secondly, the effect of the maturation process on JO(2) was studied.

METHODS

In tibialis anterior (almost exclusively type 2 fibres) muscle from young (12-17 weeks, n = 7) and mature (25-27 weeks, n = 12) KD and wild-type (WT) (12-17 weeks, n = 9; 25-27 weeks, n = 11) littermates, JO(2) was quantified in permeabilized fibres ex vivo by respirometry, using a substrate-uncoupler-inhibitor-titration (SUIT) protocol: malate, octanoyl carnitine, ADP and glutamate (GMO(3) ), + succinate (GMOS(3) ), + uncoupler (U) and inhibitor (rotenone) of complex I respiration. Citrate synthase (CS) activity was measured as an index of mitochondrial content.

RESULTS

Citrate synthase activity was highest in young WT animals and lower in KD animals compared with age-matched WT. JO(2) per mg tissue was lower (P < 0.05) in KD animals (state GMOS(3) ). No uncoupling effect was seen in any of the animals. Normalized oxygen flux (JO(2) /CS) revealed a uniform pattern across the SUIT protocol with no effect of KD. However, JO(2) /CS was higher [GMO(3) , GMOS(3) , U and rotenone (only WT)] in the mature compared with the young mice - irrespective of the genotype (P < 0.05).

CONCLUSION

Exercise intolerance and reduced activity level seen in KD mice may be explained by reduced JO(2) in the maximally coupled respiratory state. Furthermore, an enhancement of oxidative phosphorylation capacity per mitochondrion is seen with the maturation process.

Cryopreservation of human skeletal muscle impairs mitochondrial function

Previous studies have investigated if cryopreservation is a viable approach for functional mitochondrial analysis. Different tissues have been studied, and conflicting results have been published. The aim of the present study was to investigate if mitochondria in human skeletal muscle maintain functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity of oxidative phosphorylation was significantly (P < 0.05) reduced in cryopreserved human skeletal muscle samples. Cryopreservation impaired respiration with substrates linked to Complex I more than for Complex II (P < 0.05). Addition of cytochrome c revealed an increase in respiration indicating cytochrome c loss from the mitochondria. The results from this study demonstrate that normal mitochondrial functionality is not maintained in cryopreserved human skeletal muscle samples.

A serologic study of canine herpes virus-1 infection in the Norwegian adult dog population

Canine herpes virus-1 (CHV1) causes a fatal hemorrhagic disease in neonatal puppies and is associated with reproductive problems in female dogs. This serologic study was conducted to assess the seroprevalence of CHV1 infection in Norway. Blood samples were collected from clinically healthy dogs (n = 436) one yr of age and older of both genders, supplied by four small animal clinics (A, B, C and D) in different parts of the country. The immunoperoxidase monolayer assay was used for testing of CHV1 antibodies. Serum titers were recorded as the reciprocal value of the highest dilution producing specific cell staining. Titers equal to or above 80 were considered positive for exposure to CHV1. In total, 80.0% of the dogs had titers ≥80 and were classified as positive. Mean age for seronegative dogs was 4.7 yrs (95% CI 4.1-5.4) and for seropositive dogs 5.0 yrs (95% CI 4.7-5.4). Of the dogs, 32.8% displayed a weakly positive titer of 80, whereas 41.5 and 5.7% fell into the moderately (titer 160 and 320) and strongly (titer ≥640) positive categories, respectively. No association was demonstrated when comparing CHV1 antibody titers to gender or reproductive parameters like previous matings, pregnancies, births or number of puppies born. Age, visit in foreign countries and clinic explained together 78% of the variation in antibody titer categories. The percentage of positive samples differed significantly between the four clinics (A 98%, B 58.5%, C 74.6%, D 89.5%). A reasonable explanation for this finding has not been established. No information about an ongoing outbreak of CHV1 infection was available. In conclusion, this study strongly indicates that CHV1 infection is endemic in the dog population of Norway. There are significant differences in seroprevalence between geographic regions in the country.

Prehospital trauma care reduces mortality. Ten-year results from a time-cohort and trauma audit study in Iraq

BACKGROUND

Blunt implementation of Western trauma system models is not feasible in low-resource communities with long prehospital transit times. The aims of the study were to evaluate to which extent a low-cost prehospital trauma system reduces trauma deaths where prehospital transit times are long, and to identify specific life support interventions that contributed to survival.

METHODS

In the study period from 1997 to 2006, 2,788 patients injured by land mines, war, and traffic accidents were managed by a chain-of-survival trauma system where non-graduate paramedics were the key care providers. The study was conducted with a time-period cohort design.

RESULTS

37% of the study patients had serious injuries with Injury Severity Score ≥ 9. The mean prehospital transport time was 2.5 hours (95% CI 1.9 - 3.2). During the ten-year study period trauma mortality was reduced from 17% (95% CI 15 -19) to 4% (95% CI 3.5 - 5), survival especially improving in major trauma victims. In most patients with airway problems, in chest injured, and in patients with external hemorrhage, simple life support measures were sufficient to improve physiological severity indicators.

CONCLUSION

In case of long prehospital transit times simple life support measures by paramedics and lay first responders reduce trauma mortality in major injuries. Delegating life-saving skills to paramedics and lay people is a key factor for efficient prehospital trauma systems in low-resource communities.

Metformin-treated patients with type 2 diabetes have normal mitochondrial complex I respiration

AIMS/HYPOTHESIS

The glucose-lowering drug metformin has been shown to inhibit complex I of the mitochondrial electron transport chain in skeletal muscle. To investigate this effect in vivo we studied skeletal muscle mitochondrial respiratory capacity and content from patients with type 2 diabetes treated with metformin (n = 14) or sulfonylurea (n = 8) and healthy control (n = 18) participants.

METHODS

Mitochondrial respiratory capacity was measured ex vivo in permeabilised muscle fibres obtained from the vastus lateralis muscle of all participants. The respiratory response to in vitro titration with metformin was measured in controls. Citrate synthase (CS) activity, and fasting plasma glucose, insulin and HbA(1c) levels were measured and body composition was determined.

RESULTS

Participants were matched for age, BMI and percentage body fat. Fasting plasma glucose concentrations were higher (p < 0.05) in those treated with sulfonylureas and metformin than in controls. CS activity was comparable between metformin-treated and control participants, but tended to be lower in those receiving sulfonylureas. Mitochondrial respiratory capacity with substrates for complex I and complex I and II was comparable in the groups, both when estimated per mg of tissue and when normalised to CS activity. In vitro metformin titration demonstrated a dose-dependent inhibitory effect on complex I and II in human skeletal muscle at suprapharmacological concentrations.

CONCLUSIONS/INTERPRETATION

Metformin treatment does not inhibit mitochondrial complex I respiration in the electron transport chain in human skeletal muscle of patients with type 2 diabetes when measured ex vivo. Inhibition of complex I and II respiration in controls was demonstrated by metformin titration in vitro at doses well above those observed during metformin treatment.

Willingness-to-pay for benefits associated with basal insulin treatment of type 2 diabetes

Data from a 20-week trial comparing insulin detemir and neutral protamine Hagedorn (NPH) insulin in insulin-naïve people with type 2 diabetes were analyzed using willingness-to-pay (WTP) data, a proxy for patient preference. The advantages of insulin detemir relative to NPH insulin with respect to a lower hypoglycemia rate and less weight gain were associated with a value of €27.87 per month.

Assessing possible celiac disease by an HLA-DQ2-gliadin Tetramer Test

OBJECTIVES

Investigation of uncertain celiac disease (CD) in patients already on a gluten-free diet (GFD) is difficult. We evaluated HLA-DQ2-gliadin tetramers for detection of gluten-specific T cells in peripheral blood and histological changes in the duodenum after a short gluten challenge as a diagnostic tool.

METHODS

HLA-DQ2+ individuals on a GFD for at least 4 weeks were investigated; 35 with uncertain diagnosis, 13 CD patients, and 2 disease controls. All participants had a challenge with four slices of gluten-containing white bread, daily for 3 days (d1-d3). An esophagogastroduodenoscopy with biopsy sampling was done on d0 and d4. Biopsies were scored according to revised Marsh criteria. Peripheral blood CD4+ T cells were isolated, stained with HLA-DQ2-gliadin peptide tetramers, and analyzed by flow cytometry on d0 and d6.

RESULTS

After challenge, a positive tetramer test was seen in 11/13 CD patients. Four of these subjects also showed typical histological changes on challenge. Of the 35 patients with uncertain diagnosis, 3 were diagnosed with CD. Two of these three patients had both positive tetramer staining and histological changes in biopsies after challenge.

CONCLUSIONS

Tetramer staining for gluten-specific T cells is a sensitive method in detecting an immune response in CD patients after a short gluten challenge. The prevalence of CD in the group with self-prescribed GFD was about 10%.

Increased mitochondrial substrate sensitivity in skeletal muscle of patients with type 2 diabetes

AIMS/HYPOTHESIS

Mitochondrial respiration has been linked to insulin resistance. We studied mitochondrial respiratory capacity and substrate sensitivity in patients with type 2 diabetes (patients), and obese and lean control participants.

METHODS

Mitochondrial respiration was measured in permeabilised muscle fibres by respirometry. Protocols for respirometry included titration of substrates for complex I (glutamate), complex II (succinate) and both (octanoyl-carnitine). Myosin heavy chain (MHC) composition, antioxidant capacity (manganese superoxide dismutase [MnSOD]), citrate synthase activity and maximal oxygen uptake (VO2) were also determined. Insulin sensitivity was determined with the isoglycaemic-hyperinsulinaemic clamp technique.

RESULTS

Insulin sensitivity was different (p < 0.05) between the groups (patients<obese controls<lean controls). MnSOD was lower in patients than in lean controls. MHC I content was lowest in patients (37 ± 11% [mean ± SE] vs 53 ± 6% and 56 ± 4%) vs obese controls and lean controls, respectively. VO2 was highest in lean controls (40 ± 3 ml min(-1) kg(-1) [mean ± SE]) compared with patients (25 ± 2) and obese controls (27 ± 2). Mitochondrial content (citrate synthase) was higher (p < 0.05) in lean controls than in patients and obese controls. When normalised for mitochondrial content by citrate synthase, mitochondrial respiratory capacity was similar in all groups. However, the half maximal substrate concentration (C(50)) for complex I was significantly lower (p = 0.03) in patients (1.1 ± 0.2 mmol/l [mean ± SE]) than in obese (2.0 ± 0.3) and lean (1.8 ± 0.3) controls. Likewise, C(50) for complex II was lower (p = 0.02) in patients (3.5 ± 0.2 mmol/l [mean ± SE]) than in obese controls (4.1 ± 0.2), but did not differ from that in lean controls (3.8 ± 0.4). Substrate sensitivity for octanoyl-carnitine did not differ between groups.

CONCLUSIONS/INTERPRETATION

Increased mitochondrial substrate sensitivity is seen in skeletal muscle from type 2 diabetic patients and is confined to non-lipid substrates. Respiratory capacity per mitochondrion is not decreased with insulin resistance.

Muscle characteristics in young Norwegian-Swedish Coldblooded Trotters and associations with breeding index, body size and early training

REASONS FOR PERFORMING STUDY

The trotting speed of Norwegian-Swedish Coldblooded Trotters (NSCTs) is, although inferior to Standardbred speeds, gradually increasing. This development is mainly attributed to breeding progresses. Characteristics of the middle gluteal muscle have recently been described in a small number of these horses but the actual spread in muscle parameters within the population is unknown.

OBJECTIVES

To describe the characteristics of the middle gluteal muscle and their naturally occurring variability in young NSCT horses and investigate possible association with body size, individual breeding index and early training.

METHODS

Biopsies of the middle gluteal muscle of 144 NSCT horses born in 2005 were collected at age 17-24 months. The horses were randomly selected by stratified sampling with gender and paternal progeny as stratification factors. The muscle samples were analysed for fibre type composition, fibre type areas, capillary supply and the activity of the key metabolic enzymes citrate synthase, 3-OH-acyl-CoA-dehydrogenase and lactate dehydrogenase. Correlation analysis including muscle parameters and body size, individual breeding index and early training was performed.

RESULTS

Large interindividual differences were identified in muscle characteristics. Male horses had higher percentages of type IIA fibres and lower percentages of type IIX fibres than age-matched females. Fibre type areas followed the order type IIX>IIAX>IIA>I, while the capillary supply per fibre type area increased in the opposite order. No gender-related differences were found in fibre type areas or capillary supply. Height was correlated to the relative area of type I fibres. Early training was associated with increased oxidative capacity and increased percentage of type IIA fibres. The lowest breeding index was found in untrained horses.

CONCLUSIONS

Muscle characteristics differ among young NSCT horses, but the innate oxidative capacity seems to be lower than in Standardbreds of comparable age. Early training may influence on these parameters.

Prediction of early race starts in Norwegian-Swedish Coldblooded Trotters

Background

Less than a third of Norwegian-Swedish Coldblooded Trotters (NSCTs) have started racing as three year olds since the year 2000 despite the fact that large sums are paid out as price-money in the three year season. Recruitment races are arranged by the Norwegian Trotting Association (NTA) to stimulate early training. The management of young horses varies considerably and a large majority is reared by amateurs. The aim of the present study was to identify predictors of early race starts in young NSCT horses under field conditions.

Methods

Of the 801 registered NSCT horses born in 2005, 144 were randomly selected by stratified sampling with gender and paternal progeny as stratification factors. All horses were examined clinically. Further data were collected from NTA and by interviews of breeders, owners and trainers. The set of dependent variables consisted of "passed recruitment race", "start in regular race by the end of the three year season" and "start in regular race by the end of October in the four year season". Univariate and logistic regression analyses were performed.

Results

Genetic performance potential, as indicated by best linear unbiased prediction (BLUP) indices, was the major predictor of the three dependent variables despite large variation in management. Dam's index was a better predictor than sire's index. However, the probability of early race starts in a horse with a low genetic performance potential can be increased by a favourable management. Examples of advantageous management factors in the present study were a flat pasture the first summer and early training. Nearly all horses racing in the three or four year seasons had passed a recruitment race in the two year season.

Conclusions

The results confirm the value of the published BLUP index as an important tool for the NSCT breeding program. Recruitment races stimulate early training.