Impact of diet management and composition on vitamin B12 concentration in milk of Holstein cows.

As vitamin B12 is only synthesized by bacteria, ruminant products, especially dairy products, are excellent sources of this vitamin. This study aims to identify if diet and cow characteristics could affect vitamin B12 concentration in milk of dairy cows. Information on 1484 first, 1093 second and 1763 third and greater parity Holstein cows in 100 herds was collected during three consecutive milkings. During the first morning milking, all dietary ingredients given to cows were sampled and quantities offered were recorded throughout the day. Nutrient composition of ingredients was obtained by wet chemistry to reconstitute nutrient composition of the ration. Milk samples were taken with in-line milk meters during the evening milking of the 1st day and the morning milking of the 2nd day and were analyzed for vitamin B12 concentration. Milk yields were recorded and milk components were separately analyzed for each milking. Daily vitamin B12 concentration in milk was obtained using morning and evening vitamin B12 concentrations weighted with respective milk yield, then divided by daily yield. To decrease the number of interdependent variables to include in the multivariable model, a principal component analysis was carried out. Daily milk concentration of vitamin B12 averaged 3809±80 pg/ml, 4178±79 pg/ml and 4399±77 pg/ml for first, second and third, and greater lactation cows. Out of 11 principal components, six were significantly related to daily milk concentration of vitamin B12 when entered in the multivariable model. Results suggested that vitamin B12 concentration in milk was positively related to percentage of fiber and negatively related to starch as well as energy of the diet. Negative relationships were noted between vitamin B12 concentration in milk and milk yield as well as milk lactose concentration and positive relationships were observed between vitamin B12 concentration in milk and milk fat as well as protein concentrations. The percentages of chopped mixed silage and commercial energy supplement in the diet as well as cow BW were positively related to vitamin B12 in milk and percentages of baled mixed silage, corn and commercial protein supplement in the ration were negatively related to vitamin B12 concentration in milk. The pseudo-R2 of the model was low (52%) suggesting that diet and cow characteristics have moderate impact on vitamin B12 concentration in milk. Moreover, when entering solely the principal component related to milk production in the model, the pseudo-R2 was 46%. In conclusion, it suggests that studied diet characteristics have a marginal impact on vitamin B12 concentration in milk variation.

Upper esophageal sphincter myotomy in oculopharyngeal muscular dystrophy: long-term clinical results.

From 1980 to 1995, 53 patients with oculopharyngeal muscular dystrophy (OPMD) underwent an upper esophageal sphincter (UES) myotomy for the control of marked dysphagia. From this number, a group of 21 patients had been evaluated for preoperative and postoperative symptoms in 1987. The same clinical assessment was performed in 1995 by an independent evaluator for a total of 37 patients including 12 patients from the first group. As a whole, after a mean follow-up of 6.2 years, surgery succeeded in 18 patients (49%), gave a partial improvement in 12 (32%) and failed in seven (19%). The 12 patients evaluated twice (in 1987 and 1995) have had very good early results, 8-69 months after UES myotomy: dysphagia was totally relieved in eight patients, occurred rarely in three and was moderate in one. Nevertheless, the very long-term follow-up (8 years later) has shown a recurrence of the swallowing and tracheobronchial symptoms in many cases.

cis-1,3,4,6,7,11b-Hexahydro-2-methyl-7-phenyl-2H-pyrazino[2,1-a] isoquinoline: a new atypical antidepressant.

Molecular modelling studies suggested the synthesis of cis-1,3,4,6,7, 11b-hexahydro-2-methyl-7-phenyl-2H-pyrazino[2,1-a]isoquinoline (7a) as a rigid analogue of the atypical antidepressant mianserin. Acylation of 2,2-diphenylethylamine with chloroacetyl chloride gives the chloroacetamide (2). Cyclization of 2 with P2O5 in xylene provides 1-(chloromethyl)-3,4-dihydro-4-phenylisoquinoline (3). Amination of 3, followed by reduction, gives the isomeric (aminomethyl)tetrahydroisoquinolines (4a and 5). Treatment of 4a with diethyl oxalate, followed by reduction of the diamide with borane, provides 7a. A variety of N-substituted, aromatic substituted, and optically resolved derivatives were prepared and evaluated for anticholinergic, antihistaminic, and antidepressant activity. In particular, the target cis isomer 7a as predicted from the modelling studies appears to possess excellent atypical antidepressant activity. This activity resides in the (+)-S,S optical isomer 10, which has the same absolute configuration as (+)-mianserin.

Retrograde amnesia induced by hypoxia and electroconvulsive shock in two rat strains.

Hypoxia or electroconvulsive shock (ECS) was administered to two strains of rats following one trial passive avoidance training. ECS produced retrograde amnesia in the Blue Spruce Farms Long Evans hooded rat when administered within 10 sec after training and in the Charles River albino rat when administered within 75 sec after training. Hypoxia was effective in producing retrograde amnesia when administered up to 40 min after training in the hooded rat but only when administered between 20 and 30 min after training in the albino rat. The importance of strain variability is discussed.

A possible mechanism for diisopropylfluorophosphate-induced memory loss in rats.

Passive avoidance retention and cortical [H3]-quinuclidinyl benzilate (QNB) binding were examined in rats that were chronically treated with diisopropylfluorophosphate (DFP), an irreversible acetylcholinersterase inhibitor. Retention of a passive avoidance response in DFP-treated rats was significantly lower when compared to vehicle-treated controls. Passive-avoidance retention decreased from 93% in control animals to 68% in DFP-treated rats. QNB binding studies revealed the density of muscarinic receptors in cortical homogenates was significantly reduced from 0.95 +/- 0.04 pmole/mg protein in controls to 0.72 +/- 0.04 pmole/m protein in DFP-treated rats. Scatchard analysis of QNB binding curves did not reveal a decrease in affinity of muscarinic receptors for QNB. Based on data that DFP causes a reduction in cholinergic receptors, this study supports the hypothesis that central cholinergic receptors are associated with mechanisms involved in memory storage.

Survey of food-related waste management practises in New Brunswick health establishments.

A survey was conducted jointly by Université de Moncton and the New Brunswick (N.B.) Department of Health and Community Services to generate information on waste management practises within health care institutions. The objectives of the survey were: 1) to identify the type of waste management methods in place in N.B. health establishments; 2) to identify the major difficulties associated with recycling food-related waste; 3) to study the attitudes and beliefs of food service managers toward waste management. Data were collected through a questionnaire mailed to food service managers. Results indicated that 86% of establishments were involved in waste reduction. There were no statistically significant differences in reduction practices between hospitals and nursing homes or between the size of these establishments (P = 0.11). The same applied for reutilization (P = 0.09) where 93% of the establishments were involved. Recycling was carried out in 64.8% of the establishments. Major obstacles to recycling included the lack of pickup services, the lack of storage space, and the absence of buyers for recyclable materials. The results of this survey will help in the formulation of policies, strategies, and recommendations for better protection of the environment.

Transcutaneous energy transfer system performance evaluation.

A transcutaneous energy transfer (TET) system has been developed to power implantable devices such as artificial hearts, defibrillators, and electrical stimulators. Transcutaneous coupling of power to these implanted devices remains a favorable alternative as percutaneous lines are avoided in order to eliminate the potential of infection and allow patient mobility. In vitro, in vivo, ex vivo, and human cadaver studies of the electrohydraulic ventricular assist device TET have demonstrated that power can be transmitted over a range of skin thicknesses of 3-15 mm and can tolerate radial misalignments of up to 20 mm. Sensitivity to coil separation and radial misalignment variations has been addressed by the development of an auto-tuning TET. The system has only a 10% attenuation in secondary coil voltage when metallic objects are in contact with the primary coil. The system has demonstrated a power transfer efficiency of 60-80% for power demands from 5 to 70 W. The TET secondary coil will provide an output voltage of 10-25 V for current demands from 0.5 to 4.0 A. TET chronic studies in porcine models have demonstrated no adverse effect to the tissue when up to 40 W of power can be delivered to an implanted load without the tissue-contacting surface of the coil exceeding 42 degrees C. In conclusion, the TET is a feasible alternative for tether-free power transmission.