Relationship between residual feed intake and digestive traits of fattening bulls fed grass silage- or maize silage-based diets.

Several studies tried to identify digestive determinants of individual variation in feed efficiency between fattening bulls, because of their importance for breeding and management strategies. Most studies focused on single traits or single diet. Little is known about diet-dependent differences in digestive determinants and on their relative importance in distinguishing divergent residual feed intake (RFI) bulls. This research aimed (i) to identify digestive traits that differed between bulls diverging in RFI and fed a maize silage- or a grass silage-based diets; (ii) to highlight the relationships between RFI and digestive traits, and (iii) to explore the hierarchy among digestive traits in discriminating RFI divergent bulls. After an initial RFI test of 84 days on 100 Charolais growing bulls fed two different diets based on grass silage (GS), or maize silage (MS), the 32 most RFI divergent bulls were selected (eight efficient RFI- and eight inefficient RFI+ bulls per diet) and measured thereafter for total tract apparent digestibility and transit rate, enteric gas emissions (CH4 and H2), rumen pH, and feeding behaviour. Rumen particle size and visceral organ and reticulo-omasal orifice (ROO) sizes and rumen and ileum histology were measured at slaughter on the 32 selected extreme RFI bulls. Irrespective of the diet, efficient bulls (RFI-) had lower rumen size, CH4 yield (g/kg DM intake; tendency), lower number of cells in the ileal crypts, tended to have longer time of rumen pH below 5.8 and lower proportion of small size particles in rumen content than non-efficient bulls (RFI+). A long-term test for feed efficiency (197 d on average) was performed on the whole experimental period until slaughter for the 100 animals. The long-term RFI value was negatively related to time spent in activity other than ingestion, rumination, and resting, and positively related (tendency) to the duration of ingestion events, to rumen and abomasum size, irrespective of the diet. Diet-dependent effects were noted: with GS, efficient (RFI-) bulls showed a slower transit rate, whereas with MS, efficient (RFI-) bulls tended to have shorter resting events and a smaller ROO than inefficient bulls (RFI+). The transit rate and the ROO size tended to be positively related, while total tract apparent digestibility of nitrogen was negatively related to long-term RFI value, but only in GS. Rumen size appeared as the most discriminating digestive variable between RFI divergent bulls, but this result should be validated on a larger number of animals and diets.

Individual methane emissions (and other gas flows) are repeatable and their relationships with feed efficiency are similar across two contrasting diets in growing bulls.

In the current economic and environmental context, the selection of livestock phenotypes combining high feed efficiency (FE) and low greenhouse gas emissions is interesting. This study aimed to quantify methane (CH4) emissions and other gas flows (carbon dioxide (CO2) and dihydrogen (H2) emissions, oxygen (O2) consumption) in growing bulls fed with two contrasting diets in order to (i) evaluate the persistence of individual variability in gas flows through time, and (ii) assess the inter-individual relationship between gas flows and FE across diets. Charolais bulls were fattened for 6 months during two consecutive years in two independent batches (50-51 per year). In each batch, half of the animals received a total mixed ad libitum ration either based on maize silage (62% dietary DM) or high-starch concentrate (MS-S), and half based on grass silage (59% dietary DM) and high-fibre concentrate (GS-F). The absolute gas flows (g/d) were individually measured with 2 GreenFeed systems during 88 days (group 1) and 64 days (group 2). All gas flows were also expressed in g/kg DM intake (gas yield), in g/kg average daily gain (CH4 intensity) and residual of daily emissions for CH4 (R CH4). Different FE metrics (residual feed intake (RFI), residual gain (RG) and feed conversion efficiency (FCE)) were investigated during the same period. The relationships between gas flows and FE metrics were tested by linear regression with the diet as fixed effect. For both diets, we observed a consistent individual variability over the measurement period for absolutes values (g/d) of CH4, CO2, and O2 (repeatability >0.7 for GS-F and >0.6 for MS-S). Gas flows (g/d) were positively correlated with RFI with both diets: animals that ingested food in excess of their theoretical maintenance and growth requirements emitted more CH4, CO2 and consumed more O2. The positive relationship between absolute CH4 emissions and RFI highlighted the interest for low-CH4 emitters and efficient growing bulls when fed with high-energy diets rich in starch or fibre. For both diets, RCH4, CH4 yield and CH4 intensity were not related to RFI whereas a significant negative relationship was reported between CH4 intensity and RG, and FCE. These data suggest that intake is the main driver of the phenotypic relationships between CH4 traits and RFI. Further studies including larger numbers of animals on highly contrasting energy diets are needed to investigate the underlying biological regulatory mechanisms of the methanogenic potential of an animal in relation to production traits.

The functional anatomy of attention in humans: cerebral blood flow changes induced by reading, naming, and the Stroop effect.

We measured changes in regional cerebral blood flow (rCBF) induced by reading, naming, and the Stroop effect in 12 right-handed normal volunteers. rCBF was quantified with a single-photon emission computerized tomograph after intravenous injection of 133Xe. Data were analyzed using predetermined regions of interest and a linear model. A significant relative activation was revealed in the right superior mesial frontal region during the Stroop effect.

Reversibility of hemodynamic hypofrontality in schizophrenia.

Regional cerebral blood flow (CBF) was studied in 51 young schizophrenics. A significant decrease of CBF was seen in frontal and prefrontal regions (hypofrontal pattern) in chronic patients whose disease had evolved for more than 2 years and who were in remission. This hypofrontal pattern was reversible, as it disappeared during exacerbation of the disease. In 10 patients who had not been treated with neuroleptics for several weeks, we found a dopaminergic hypersensitivity in the frontal lobes, as a weak dose of piribedil restored near-normal frontality. This may reflect either the role of neuroleptic washout or a primitive dopaminergic depletion, as proposed by some authors in the chronic form of schizophrenia.

Cerebral circulatory effects of a dopaminergic agonist (apomorphine) in the dog.

Dopaminergic influence upon cerebral circulation was studied in 12 adult mongrel dogs, local cerebral blood flow (lCBF) being measured by the microspheres method. The intravenous injection of apomorphine (0.1 mg/kg) produced heterogeneous effects on lCBF; an increase in lCBF reaching the level of statistical significance was observed in frontal and sensory motor cortices, whereas blood flow was not significantly altered in the other regions examined. When the animals are considered individually, a widespread response was generally observed. Local cerebral blood flow increased from 16% to 85% (depending on the regions examined) in 4 animals, and tended to decrease (particularly in the caudate nucleus) in the 8 others. These opposite effects cannot be related with changes in general metabolic or hemodynamic parameters (PaCO2, PaO2, pH, and arterial pressure). It is thus concluded that the effect of dopaminergic stimulation upon cerebral circulation is more complex than previously reported. These effects could only be partly mediated via vascular receptors and could be the result of modifications of the local metabolic level.

Cerebral blood flow studied by Xenon-133 inhalation technique in parkinsonism: loss of hyperfrontal pattern.

Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of 133Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid 133Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the "hyperfrontal distribution" in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.

A comparison of subcutaneous sumatriptan and dihydroergotamine nasal spray in the acute treatment of migraine.

We compared the efficacy and safety of subcutaneous (SC) sumatriptan (6 mg) with that of dihydroergotamine (DHE) nasal spray (1 mg plus optional 1 mg) in the acute treatment of migraine. Two hundred sixty-six adult migraineurs (International Headache Society criteria) completed a multicenter, double-blind, double-dummy, cross-over study. Patients took SC sumatriptan for one attack and DHE nasal spray for the other in random order. Data from both treatment periods show that at all time points from 15 minutes, SC sumatriptan was significantly better than DHE nasal spray at providing both headache relief (moderate/severe headache improving to mild/none) and resolution of headache. Similarly, SC sumatriptan was superior to DHE nasal spray for the other efficacy end points assessed in the study. Patients reported that both treatments were well tolerated. Adverse events were reported by 43% of patients taking SC sumatriptan and 22% of patients taking DHE nasal spray. These were usually mild and transient. We conclude that subcutaneous sumatriptan has a faster onset of action than DHE nasal spray and provides greater relief of acute migraine symptoms.

Epinephrine, norepinephrine, and dopamine during a 4-day head-down bed rest.

Head-down bed rest at an angle of 6 degrees was used as an experimental model to simulate the hemodynamic effects of microgravity, i.e., the shift of fluids from the lower to the upper part of the body. The sympathoadrenal activity during acute (from 0.5 to 10 h) and prolonged (4 days) head-down bed rest was assessed in eight healthy men (24 +/- 1 yr) by measuring epinephrine (E), norepinephrine (NE), dopamine (DA), and methoxylated metabolite levels in their plasma and urine. Catecholamine (CA) and methoxyamine levels were essentially unaltered at any time of bed rest. Maximal changes in plasma were on the second day (D2): NE, 547 +/- 84 vs. 384 +/- 55 pg/ml; DA, 192 +/- 32 vs. 141 +/- 16 pg/ml; NS. After 24 h of bed rest, heart rate decreased from 71 +/- 1 to 63 +/- 3/min (P less than 0.01). Daily dynamic leg exercise [50% maximum O2 uptake (VO2 max)] used as a countermeasure did not alter the pattern of plasma CA during bed rest but resulted in a higher urinary NE excretion during postexercise recovery (+45% on D2; P less than 0.05). The data indicate no evident relationship between sympathoadrenal function and stimulation of cardiopulmonary receptors or neuroendocrine changes induced by central hypervolemia during head-down bed rest.

A multi-centre, double-blind trial of tizanidine, a new antispastic agent, in spasticity associated with hemiplegia.

A double-blind study was carried out in 105 patients with chronic spasticity associated with hemiplegia in order to compare the efficacy and tolerability of tizanidine with that of diazepam. Dosage was increased progressively, if tolerated, to a maximum of 24 mg tizanidine or 30 mg diazepam per day at the end of 2 weeks. The optimum dosage was then maintained for 6 weeks. Efficacy and tolerability parameters were assessed after 2 and 8-weeks' therapy. Patients on tizanidine but not those on diazepam showed a statistically significant improvement in functional status, as assessed by walking distance on flat ground. Analysis of the stretch reflex in four groups of muscles showed that both tizanidine and diazepam reduced the duration of contractions and increased the angle at which contraction occurred, but there were no significant differences between the two drugs. Clonus of the triceps surae resolved in 48% of tizanidine and 40% of diazepam patients. Evaluation of the effect of therapy revealed an improvement with each drug in approximately 83% of patients, with the overall evaluation being slightly (but non-significantly) in favour of tizanidine. There were fewer discontinuations of treatment in the tizanidine group as a result of side-effects. It would appear, therefore, that tizanidine is an effective and well-tolerated drug in the treatment of cerebral spasticity.

Cortical atrophy in Parkinson disease: correlation between clinical and CT findings with special emphasis on prefrontal atrophy.

Thirty-seven patients with Parkinson disease were evaluated clinically and with computed tomography in order to determine the incidence of prefrontal atrophy. An age-matched healthy control group was also scanned. The computed tomographic criteria used were the width of cortical sulci and ventriculocerebral indices. Parkinsonian patients with frontal cortical atrophy represent only one patient out of three. They are much older than parkinsonian patients with normal computed tomographic scans, and the onset of their illness occurs later. No significant difference was found according to gender, parkinsonian clinical triad, psychomotor study, or mean duration of illness and/or dopatherapy to the time of computed tomography. This work seems to separate two Parkinson diseases: one beginning before 65 years and damaging the nigrostriate system, and another beginning after 65 years and damaging both the nigrostriate system and the cortex, particularly the frontal cortex.

[Peripheral neuropathy with cryoglobulinemia (author's transl)]. / Neuropathies périphériques associées à une cryoglobulinémie.

The author describe 2 personal observations of peripheral neuropathy with cryoglobulinemia and the 28 cases previously recorded are reviewed. The characteristics of the usually sensorimotor neuropathy are not specific. Nevertheless, the association with purpura, Raynaud's syndrome and leg ulcers and the inconstant aggravation of the symptoms with cold allow the diagnosis to be suspected on clinical grounds. Cryoglobulin can be recognised by immunoelectrophoresis and classified as type I monoclonal, types II and III mixed and polyclonal. Associated disease should be looked for; lymphocytic proliferation or auto-immune disease. If none is found a diagnosis of essential cryoglobulinemia can be made but with caution as cryoglobulinemia can precede by several years the appearance of associated disease.

Pharmacological exploration of dopamine hypersensitivity in migraine patients.

Patients with migraine show a hypersensitivity to dopamine or its agonists. One of these, piribedil, was administered as 0.1 mg/kg intravenously over 30 min to subjects with either migraine or other types of headache. This test provoked in migraine patients an increase of the cerebral blood flow and the peripheral signs of dopamine hypersensitivity:- nausea or vomiting and a rapid fall in blood pressure. In contrast, in those subjects with chronic non-migrainous headache, the administration of piribedil had no effect. The piribedil test appears to possess good specificity vis à vis migraine, enabling a differential diagnosis from atypical periodic headache, a condition difficult to consider as migraine or psychogenic headache on clinical grounds alone.

[Acebutolol and cerebral blood flow of the moderately hypertensive aged subject]. / Acébutolol et débit sanguin cérébral du sujet âgé moyennement hypertendu.

In 17 moderate hypertensive patients (mean age = 67 +/- 8.8) the effects of a chronic oral administration of the beta blocking agent acebutolol on regional cerebral blood flow (rCBF) was studied using the non invasive 133 Xenon inhalation technique. The results was compared to the rCBF obtained in an age matched normal control group. Our study shows that during long term therapy low doses of acebutolol (200 mg/daily) the rCBF is unaffected by a decrease (20 mmHg) of the mean arterial blood pressure. The relative hypofrontality of the elderly hypertensive patients leads to be corrected by acebutolol.

[Effects of captopril on the cerebral blood flow in the hypertensive aged subjects]. / Effets du captopril sur le débit sanguin cérébral du sujet âgé hypertendu.

Cerebral blood flow (CBF) was measured in 13 subjects (4 men and 9 women, mean age +/- SD = 63 +/- 7) with moderate, uncomplicated and untreated hypertension and 11 normotensive subjects (6 men and 5 women, mean age +/- SD = 66 +/- 5). A second CBF measurement was performed in hypertensive subjects after a 60 days randomized double blind treatment with either captopril, 75 mg a day (n = 8) or placebo (n = 5). CBF was quantified using the 133Xe inhalation technic and 16 stationary detectors by hemisphere. Comparison of CBF values between hypertensive subjects before treatment and normotensive subjects demonstrated a decrease of CBF in the hypertensive group (49 +/- 9 vs 72 +/- 14 ml/100 g/min; p < 0.001). After the trial the results in the captopril group showed a significant fall in systolic (p < 0.001) and diastolic (p < 0.05) blood pressure and a significant increase in CBF (60 +/- 14 vs 49 +/- 11 ml/100 g/min; p < 0.05). In the placebo group there was no change in blood pressure and CBF (Table). [Table; see text] Our results demonstrate a decrease in CBF of uncomplicated and untreated elderly hypertensive subjects. This decrease is reversible under chronic treatment with captopril.

Effects of 28-day head-down tilt with and without countermeasures on lower body negative pressure responses.

This study was performed to determine the effects of 28 d of head-down tilt (HDT) (simulated weightlessness) on cardiovascular responses to orthostatic stress induced by lower body negative pressure (LBNP) (before, during, and after HDT) and +60 degrees head-up tilt (before and after HDT) in 12 subjects. Half of them underwent countermeasures (CM) of regular muscular exercise (isometric and isokinetic training) and LBNP sessions (-30 mm Hg) as generally performed during spaceflight; the other six were a control group (C). The countermeasure effect on the orthostatic responses to LBNP and tilt test was assessed by studying the changes after HDT in the two groups. Essentially, blood pressure was better maintained in group CM in the tilt test after HDT (MBP at the end of the tilt vs. baseline value: +16% (CM); -19% (C)). LBNP and muscular exercise may have contributed to this improvement. One of the probable contributing factors is the relative conservation of plasma volume, at the end of HDT, in group CM (-2.2%), compared to group C (-11.2%). Transcranial Doppler (TCD) recordings of middle cerebral artery (MCA) velocities permitted indirect evaluation of cerebral blood flow changes during the orthostatic tests. MCA velocities decreased significantly although slightly (-7 to -12%) during LBNP sessions without changes along the HDT showing that the cerebral circulation was well preserved in each group. On the other hand, subjects undergoing presyncopal symptoms presented a drop in MCA velocities, suggesting a decrease in cerebral blood flow.

Cardiovascular and hormonal changes induced by a simulation of a lunar mission.

BACKGROUND: This is the first simulation of a 14-d lunar mission including 6 d on the Moon. HYPOTHESIS: We hypothesized that a lunar gravity simulation in the middle of a head-down tilt (HDT) might result in some reversal of body fluid/hormonal responses, and influence cardiovascular deconditioning. METHODS: Six men (28 +/- 2.5 yr) were placed in bed rest (BR): in (HDT) (-6 degrees) to simulate microgravity during the travel (two 4-d periods), and in head-up tilt (HUT) (+10 degrees) (6-d period) to simulate lunar gravity (1/6 g). Muscular exercise was performed during the HUT period to simulate 6 h of lunar EVA. Heart rate variability (HRV) and hormonal responses were studied. RESULTS: An orthostatic arterial hypotension was observed after the BR (tilt test) in 4 of the 6 subjects. Plasma volume measured at D14 decreased by -11.1% (vs. D-3, sitting position). A decrease in atrial natriuretic peptide (26 +/- 3.5 pg.ml-1 (D14) vs. 37.9 +/- 3.5 pg.ml-1 (D-3, sitting) and an increase in plasma renin activity (198 +/- 9.2 mg.L-1.min-1 (D14) vs. 71 +/- 9.2 mg.L-1.min-1 (D-3, sitting) were observed during the BR, more pronounced in HUT at 7:00 p.m. Sympathetic-parasympathetic balance (HRV) at rest showed a decrease in parasympathetic indicator and an increase in sympathetic indicator in BR (p < 0.05), without differences within HDT and HUT periods. CONCLUSION: These changes were mostly similar to those reported in spaceflights, and HDT. Although the exposure to 1/6 g with exercise modified some hormonal and body fluid responses, this partial gravity simulation was not sufficient to prevent the decrease in orthostatic tolerance observed here as well as after Apollo lunar missions.

[Migraine and the idiopathic Raynaud phenomenon]. / Migraine et phénomène de Raynaud idiopathique.

The successive onset of spasms of distal arteries of the limbs and complicated migraine in a young migrainous woman raised the possibility of a common mechanism for both disorders. Three similar cases have been reported and two recent epidemiological studies have shown the frequent association of migraine attacks and Raynaud's phenomenon or variant angina in a individual patient. The possible role of vasospasm in triggering the migrainous aura is discussed.

[Cerebral blood flow and meningeal hemorrhage. An aid to the surgical decision]. / Débit sanguin cérébral et hémorragie méningée. Aide à la décision opératoire.

One hundred and eleven measurements of cerebral blood flow (C.B.F.) were performed using the Xenon 133 inhalation method in 80 cases of spontaneous subarachnoid hemorrhage of which 59 were due to ruptured aneurysms. This method is non-traumatic, reproducible and dependable. A correlation was found between clinical condition and C.B.F. values, but in a number of cases which cannot be dismissed, very low mean C.B.F. values or ischemic foci were revealed where clinical state gave no indication. A poor correlation appeared between vasospasm seen by angiography and ischemic foci detected by isotopic technique. Patients' age influenced C.B.F. values but not clinical evolution. No correlation was found between C.B.F. values and cisternal blood seen on CT scan. C.B.F. values, measured in the first two weeks of illness, were significantly higher in those patients having favorable outcome, whatever their clinical state at the time of C.B.F. measurement (comas excluded). The figure of 60 ml/100 g/min for mean cortical flow seemed to be a critical level below which the risk of complication was greater. Below this level or in cases or ischemic foci, surgery was delayed. Thus, C.B.F. measurement promises to be a valuable prognostic tool, playing an important role in the therapeutic strategy for this type of patients.

[A case of centronuclear myopathy in adults with facio-scapulo-peroneal topography]. / Un cas de myopathie centro-nucléaire de l'adulte de topographie facio-scapulo-péronière.

A 34 year-old man had complained since childhood of weakness of the right lower limb. His mother had a myopathy. Examination showed weakness and amyotrophy of the antero-external regions of the legs, mainly on the left, moderate weakness of the right scapular girdle and slight facial weakness. Serum creatine kinase was increased. Electromyogram and CT scan images were of the myogenic type. Biopsy showed a centronuclear myopathy. The course was slowly progressive. Centronuclear myopathy is rare in adults. The facio-scapulo-humeral localization has been described in numerous other pathologic types of myopathy.

[Value of the piribedil test in diagnosing migraine. Apropos of 150 cases]. / Intérêt du test au piribédil dans le diagnostic de la migraine. A propos de cent cinquante cas.

Patients with migraine show a hypersensitivity to dopamine or its agonists. One of these, piribedil, was administered as 0,1 mg/kg intravenously over 30 minutes to 150 subjects with either migraine or other types of headache. This test provoked nausea and vomiting in 94 p. cent of patients with migraine, and a rapid fall in blood pressure requiring immediate interruption of the infusion in 69 p. cent. In contrast, in those subjects with chronic non-migrainous headache the administration of piribedil had no effect in 61 p. cent and provoked a fall in blood pressure in only 16 p. cent. The piribedil test appears to possess good specificity vis-à-vis migraine, enabling a differential diagnosis from atypical periodic headache, a condition difficult to consider as migrain or psychogenic headache on clinical grounds alone.