Effects of long-term feeding of genetically modified corn (event MON810) on the performance of lactating dairy cows

A long-term study over 25 months was conducted to evaluate the effects of genetically modified corn on performance of lactating dairy cows. Thirty-six dairy cows were assigned to two feeding groups and fed with diets based on whole-crop silage, kernels and whole-crop cobs from Bt-corn (Bt-MON810) or its isogenic not genetically modified counterpart (CON) as main components. The study included two consecutive lactations. There were no differences in the chemical composition and estimated net energy content of Bt-MON810 and CON corn components and diets. CON feed samples were negative for the presence of Cry1Ab protein, while in Bt-MON810 feed samples the Cry1Ab protein was detected. Cows fed Bt-MON810 corn had a daily Cry1Ab protein intake of 6.0 mg in the first lactation and 6.1 mg in the second lactation of the trial. Dry matter intake (DMI) was 18.8 and 20.7 kg/cow per day in the first and the second lactation of the trial, with no treatment differences. Similarly, milk yield (23.8 and 29.0 kg/cow per day in the first and the second lactation of the trial) was not affected by dietary treatment. There were no consistent effects of feeding MON810 or its isogenic CON on milk composition or body condition. Thus, the present long-term study demonstrated the compositional and nutritional equivalence of Bt-MON810 and its isogenic CON.

Hypotension during fluid-restricted abdominal surgery: effects of norepinephrine treatment on regional and microcirculatory blood flow in the intestinal tract

Vasopressors, such as norepinephrine, are frequently used to treat perioperative hypotension. Increasing perfusion pressure with norepinephrine may increase blood flow in regions at risk. However, the resulting vasoconstriction could deteriorate microcirculatory blood flow in the intestinal tract and kidneys. This animal study was designed to investigate the effects of treating perioperative hypotension with norepinephrine during laparotomy with low fluid volume replacement.

Favorable effect of priming with granulocyte colony-stimulating factor in remission induction of acute myeloid leukemia restricted to dose-escalation of cytarabine

The clinical value of chemotherapy sensitization of acute myeloid leukemia (AML) with G-CSF priming has remained controversial. Cytarabine is a key constituent of remission induction chemotherapy. The effect of G-CSF priming has not been investigated in relationship with variable dose levels of cytarabine. We randomized 917 AML patients to receive G-CSF (456 patients) or no G-CSF (461 patients) at the days of chemotherapy. In the initial part of the study, 406 patients were also randomized between 2 cytarabine regimens comparing conventional-dose (199 patients) versus escalated-dose (207 patients) cytarabine in cycles 1 and 2. We found that patients after induction chemotherapy plus G-CSF had similar overall survival (43% vs 40%, P = .88), event-free survival (37% vs 31%, P = .29), and relapse rates (34% vs 36%, P = .77) at 5 years as those not receiving G-CSF. However, patients treated with the escalated-dose cytarabine regimen benefited from G-CSF priming, with improved event-free survival (P = .01) and overall survival (P = .003), compared with patients without G-CSF undergoing escalated-dose cytarabine treatment. A significant survival advantage of sensitizing AML for chemotherapy with G-CSF was not apparent in the entire study group, but it was seen in patients treated with escalated-dose cytarabine during remission induction. The HOVON-42 study is registered under The Netherlands Trial Registry (www.trialregister.nl) as #NTR230.

Restricted or severely hindered diffusion of intramyocellular lipids in human skeletal muscle shown by in vivo proton MR spectroscopy

Although magnetic resonance spectroscopy can be used as a unique tool to study molecular diffusion, it is rarely used to measure the diffusion properties of intramyocellular and extramyocellular lipids. Lipids have very low apparent diffusion coefficients (ADCs), which make these measurements difficult and necessitate strong diffusion gradients and long diffusion times. Consequence is that these measurements have inherently low signal-to-noise ratio and are prone to artifacts. The addition of physiological triggering and individual storage and processing of the spectra is seen to be a possible approach to maximize signal intensity and achieve high reproducibility of the experiments. Thus, the optimized measurement protocol was used to investigate the diffusion properties of lipids in human skeletal muscle in vivo. At a diffusion time of about 110 ms, intramyocellular lipids show a significantly lower ADC (2.0 × 10(-6) mm(2)/s, 95% confidence interval 1.10 × 10(-6) to 2.94 × 10(-6) mm(2)/s) than extramyocellular lipids (1.58 × 10(-5) mm(2)/s, 95% confidence interval 1.41 × 10(-5) to 1.75 × 10(-5) mm(2)/s). Because the chemical properties of both lipid pools can be assumed to be similar, the difference can only be attributed to restricted or severely hindered diffusion in the intramyocellular droplets.

[Anaesthesia and breast-feeding: should breast-feeding be discouraged?]

Until a few years ago an interruption of breast-feeding for 12 or even 24 hours was recommended for breast-feeding mothers after anaesthesia, this is no longer valid. If it is the mother's wish, if she is sufficiently awake and physically able, there is no reason not to start breast-feeding a mature and healthy baby immediately after recovery from a general or regional anaesthesia. Even breast-feeding after a Caesarean delivery with administration of the common anaesthetics in the usual (single) doses is no longer considered to be a problem since the amount of the substance taken up from colostrum is vanishingly small in comparison to the amount that is transferred by transplacental routes. Neither the pharmacological properties of the drugs used in association with anaesthesia nor clinical experience justify an interruption of breast-feeding.

Cardiac tissue-restricted deletion of plakoglobin results in progressive cardiomyopathy and activation of {beta}-catenin signaling

Mutations in the plakoglobin (JUP) gene have been identified in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. However, the mechanisms underlying plakoglobin dysfunction involved in the pathogenesis of ARVC remain poorly understood. Plakoglobin is a component of both desmosomes and adherens junctions located at the intercalated disc (ICD) of cardiomyocytes, where it functions to link cadherins to the cytoskeleton. In addition, plakoglobin functions as a signaling protein via its ability to modulate the Wnt/beta-catenin signaling pathway. To investigate the role of plakoglobin in ARVC, we generated an inducible cardiorestricted knockout (CKO) of the plakoglobin gene in mice. Plakoglobin CKO mice exhibited progressive loss of cardiac myocytes, extensive inflammatory infiltration, fibrous tissue replacement, and cardiac dysfunction similar to those of ARVC patients. Desmosomal proteins from the ICD were decreased, consistent with altered desmosome ultrastructure in plakoglobin CKO hearts. Despite gap junction remodeling, plakoglobin CKO hearts were refractory to induced arrhythmias. Ablation of plakoglobin caused increase beta-catenin stabilization associated with activated AKT and inhibition of glycogen synthase kinase 3beta. Finally, beta-catenin/TCF transcriptional activity may contribute to the cardiac hypertrophy response in plakoglobin CKO mice. This novel model of ARVC demonstrates for the first time how plakoglobin affects beta-catenin activity in the heart and its implications for disease pathogenesis.

[Tremorgenic syndrome in a cattle herd after feeding silage contaminated with A. clavatus];;Tremorgenes Syndrom in einem Rinderbestand nach Verfütterung einer mit A. clavatus befallenen Silage

The clinical signs, pathological and laboratory findings of cattle suffering from a tremorgenic syndrome are described. Animals on a farm with a total of 22 cows, 18 heifers and 9 calves were fed mouldy grass and spent malt-grain silage. Five heifers were affected with muscular tremor, hyperexcitability and hypersensitivity. They were ataxic or in sternal recumbency, while their appetite remained normal. Haematology and blood chemistry in two heifers as well as cerebrospinal fluid from one sick animal were unremarkable. The pathological examination of one animal brought no macroscopic changes to light. Histological examination, however, revealed the degeneration of motor neurones in the midbrain, brain stem and spinal cord. Analysis of a silage sample provided evidence of the presence of Aspergillus clavatus, a mould capable of producing neurotoxic tremorgenic mycotoxins. Epidemiology, clinical findings, pathology and microbiological examination suggest that the five cattle were suffering from neuromycotoxicosis.

A longitudinal study of Besnoitia besnoiti infections and seasonal abundance of Stomoxys calcitrans in a dairy cattle farm of southwest France

Bovine besnoitiosis, caused by the cyst-forming apicomplexan Besnoitia besnoiti, is commonly reported in some restricted regions of South-Western Europe, and in larger regions of Africa and Asia. This infection is thought to be transmitted by blood feeding insects and is responsible for major economic losses in cattle production. A recent emergence in Europe, notified in the Centre of France, Spain and Germany, has attracted more attention to this disease. Clinical signs could appear in some animals; however, many infected cattle remain asymptomatic or show scleral-conjunctival cysts (SCC) only. Recent development of serological methods allows carrying out seroepidemiological field studies. In this respect, a long-term investigation was performed in a dairy cattle farm localized in an enzootic area of besnoitiosis of South-western France between March 2008 and May 2009. The objective was to estimate the seasonal pattern of B. besnoiti infections based on the presence of SCC and serology (ELISA and Western blot). In parallel, an entomological survey was conducted to describe population dynamics of Stomoxys calcitrans and Tabanidae species. The seroprevalence determined by Western blot in a cohort of 57 animals continuously present during the whole survey increased from 30% in March 2008 to 89.5% in May 2009 and was always higher than the prevalence based on clinically assessed SCC. New positive B. besnoitia seroconversions occurred throughout the year with the highest number in spring. In addition, many seroconversions were reported in the two months before turn-out and could be associated with a high indoors activity of S. calcitrans during this period.

Effects of nutrient restriction on mammary cell turnover and mammary gland remodeling in lactating dairy cows

The aim of this study was to investigate the effects of a severe nutrient restriction on mammary tissue morphology and remodeling, mammary epithelial cell (MEC) turnover and activity, and hormonal status in lactating dairy cows. We used 16 Holstein x Normande crossbred dairy cows, divided into 2 groups submitted to different feeding levels (basal and restricted) from 2 wk before calving to wk 11 postpartum. Restricted-diet cows had lower 11-wk average daily milk yield from calving to slaughter than did basal-diet cows (20.5 vs. 33.5 kg/d). Feed restriction decreased milk fat, protein, and lactose yields. Restriction also led to lower plasma insulin-like growth factor 1 and higher growth hormone concentrations. Restricted-diet cows had lighter mammary glands than did basal-diet cows. The total amount of DNA in the mammary gland and the size of the mammary acini were smaller in the restricted-diet group. Feed restriction had no significant effect on MEC proliferation at the time of slaughter but led to a higher level of apoptosis in the mammary gland. Gelatin zymography highlighted remodeling of the mammary extracellular matrix in restricted-diet cows. Udders from restricted-diet cows showed lower transcript expression of alpha-lactalbumin and kappa-casein. In conclusion, nutrient restriction resulted in lower milk yield in lactating dairy cows, partly due to modulation of MEC activity and a lower number of mammary cells. An association was found between feed restriction-induced changes in the growth hormone-insulin-like growth factor-1 axis and mammary epithelial cell dynamics.

Milk fatty acid profile related to energy balance in dairy cows

Milk fatty acid (FA) profile is a dynamic pattern influenced by lactational stage, energy balance and dietary composition. In the first part of this study, effects of the energy balance during the proceeding lactation [weeks 1-21 post partum (pp)] on milk FA profile of 30 dairy cows were evaluated under a constant feeding regimen. In the second part, effects of a negative energy balance (NEB) induced by feed restriction on milk FA profile were studied in 40 multiparous dairy cows (20 feed-restricted and 20 control). Feed restriction (energy balance of -63 MJ NEL/d, restriction of 49 % of energy requirements) lasted 3 weeks starting at around 100 days in milk. Milk FA profile changed markedly from week 1 pp up to week 12 pp and remained unchanged thereafter. The proportion of saturated FA (predominantly 10:0, 12:0, 14:0 and 16:0) increased from week 1 pp up to week 12 pp, whereas monounsaturated FA, predominantly the proportion of 18:1,9c decreased as NEB in early lactation became less severe. During the induced NEB, milk FA profile showed a similarly directed pattern as during the NEB in early lactation, although changes were less marked for most FA. Milk FA composition changed rapidly within one week after initiation of feed restriction and tended to adjust to the initial composition despite maintenance of a high NEB. C18:1,9c was increased significantly during the induced NEB indicating mobilization of a considerable amount of adipose tissue. Besides 18:1,9c, changes in saturated FA, monounsaturated FA, de-novo synthesized and preformed FA (sum of FA >C16) reflected energy status in dairy cows and indicated the NEB in early lactation as well as the induced NEB by feed restriction.