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Biomedical subjects

R M Jones

Publications and source records attributed to R M Jones.

At least 253 records · Page 14Linked to original sources

The control of parasitic gastroenteritis of grazing cattle in Normandy, France using the morantel sustained release bolus.

The efficacy of the morantel sustained release bolus in controlling parasitic gastroenteritis in 153 first-season grazing cattle was assessed in three separate field trials conducted in Normandy, France. In each trial, comparisons were made on weight gain performance and parasitology data (faecal worm egg counts, herbage larval counts and- in two of the trials- worm counts from principal animals sacrificed at the end of the grazing season) when bolus treatment was given either at spring turnout or in mid-season in order to determine the optimum time for bolus administration. Cattle were allocated into three groups, each group maintained on a separate but equivalent paddock constructed from the division of a larger pasture. A morantel sustained release bolus was administered to one group of animals at the time of turnout and to a second group of animals in midsummer. The third group of animals in each trial remained nontreated. The effect of the treatment on the contamination of pasture, and parasite levels and weight gain of the principal trial animals was assessed. Similar results were observed in all three trials. Faecal worm egg counts were reduced during the first part of the grazing season in animals receiving the bolus at turnout compared with mid-season treated animals where egg counts followed a pattern similar to the controls until bolus treatment at which time counts abruptly dropped to a low level. Likewise, levels of infective larvae on pastures grazed by control and mid-season treated animals followed similar patterns, increasing to a high level in late summer, while larval levels on pastures grazed by early-season treated animals remained at low levels throughout most of the season. Serum pepsinogen levels, worm counts and weight gain reflected the results from faecal worm egg and herbage larval counts indicating that early-season treatment with the bolus provided the most efficient treatment time for controlling parasitic gastroenteritis throughout the grazing season. The overall mean weight gain advantage of the early-season bolus-treated animals over the controls was 37.2 kg (P less than 0.01) while the advantage of the mid-season treated animals over controls was 13.7 kg.

Animals↗

An economic and efficacy comparison between morantel (when administered from an intraruminal bolus) and conventional anthelmintic treatment in grazing cattle.

A economic and efficacy comparison in the control of parasitism in grazing cattle was conducted between conventional anthelmintic treatment applied according to various recommended regimes and an anthelmintic treatment delivered intraruminally at a sustained level from a specially designed bolus. The bolus used was the morantel sustained release bolus which has been designed to prevent the establishment of parasite infections so that, when administered at turnout to all cattle intended to graze the same pasture, parasitologically "safe" pastures could be produced and maintained for an entire grazing season. The various conventional anthelmintic treatment regimes used for the study were selected from the most commonly recommended and used systems of treatment found in commercial use throughout Europe. A total of 471 first-season grazing calves received the morantel sustained release bolus at spring turnout in 38 field trials conducted in Austria, Belgium, Denmark, France, West Germany, Ireland, the Netherlands, Norway, Sweden and the United Kingdom. In each trial, equal numbers of control and bolus-treated animals were maintained on separate halves of a divided pasture. In 25 of the 38 field trials, the control animals received tactical therapy with conventional anthelmintic only when exhibiting signs of parasitic gastroenteritis, while in the remaining 13 trials all animals in each control group received strategic anthelmintic treatment at specified intervals during the grazing season. Compared with control animals, significant reductions in faecal worm egg output of bolus-treated animals was recorded. Subsequent reductions in herbage larval contamination developed on pastures grazed by bolus-treated animals compared with control pastures so that, overall, the bolus-treated animals out-performed the control animals in all 38 trials by a mean of 16.3 kg (P less than 0.05). Labour and management costs (for animal treatment and handling) were substantially reduced in bolus-treated animals compared with animals receiving either tactical or strategic anthelmintic treatment.

Animals↗

The use of the morantel sustained release bolus in second-season grazing cattle.

The efficacy of the morantel sustained release bolus in controlling gastrointestinal helminth infection in second-season grazing cattle was investigated on a total of seven farms in southeast England. On each farm only animals which had grazing experience from the previous summer pasturing season were used. The animals on each farm were allotted into two equal groups and turned out onto divided pastures of equal size. All the cattle in one group received a bolus at turnout while the cattle in the other group remained as nontreated controls. Assessment of the efficacy of treatment was based on comparisons of faecal worm egg output, herbage larval counts, weight gain, and the incidence of clinical parasitic gastroenteritis during the grazing season. Use of the morantel sustained release bolus led to the cessation of worm egg excretion in bolus-treated cattle during the early part of the grazing season thereby preventing a subsequent buildup of infective larvae on pasture. Although the overall results from worm egg and herbage larval counts demonstrated little measurable effect of treatment, clinical parasitic gastroenteritis was prevented in two trials where control animals became clinically affected by parasitism. Overall, the bolus-treated animals outperformed the controls by a mean of 15.1 kg (P less than 0.001).

Animals↗

Interactions between tubocurarine, pancuronium and alcuronium demonstrated in the rat phrenic nerve-hemidiaphragm preparation.

The interactions between tubocurarine, pancuronium and alcuronium on neuromuscular transmission have been studied in an isolated neuromuscular preparation (the rat phrenic nerve-hemidiaphragm). Mixtures of tubocurarine and pancuronium, and tubocurarine and alcuronium were found to have a more potent effect than the additive effects of the individual agents when given alone, that is, mixtures were synergistic. Mixtures of alcuronium and pancuronium did not exhibit this phenomenon. Possible mechanisms for these findings are discussed.

Alcuronium↗

Pneumothorax in the neonatal period.

The incidence of pneumothorax in the neonatal period is reviewed. Most infants who developed a pneumothorax were undergoing intermittent positive pressure ventilation. The most common underlying pathology associated with pneumothorax was idiopathic respiratory distress syndrome. This was the only condition in which a pneumothorax occurred in spontaneously breathing patients. The development of a pneumothorax was not significantly related to gestational age, birth weight, high ventilator inflation pressure, maximum fractional inspired oxygen concentration or the method of delivery. Evidence is presented to suggest that the development of a pneumothorax is not primarily a complication of ventilation but is due to the more severe pulmonary pathology of infants who require ventilatory assistance. Whatever the mechanism, prompt diagnosis and treatment mean that this common complication does not necessarily increase mortality.

Birth Weight↗

Familial central neurofibromatosis.

The condition of central neurofibromatosis, while well documented in neurology literature, has tended to be amalgamated into acoustic neuromas associated with peripheral neurofibromatosis (or Recklinghausen's disease) in otolaryngology literature. The history of a unique family that has demonstrated four generations of bilateral acoustic neuromas has been outlined to show that central neurofibromatosis is a distinct entity related but not identical in clinical and biochemical aspects to Recklinghausen's disease. This article in intended to acquaint the otolaryngologist with the presentation and management of central neurofibromatosis.

Acoustic Impedance Tests↗

Bronchodilator effects of disodium cromoglycate in exercise-induced bronchoconstriction.

Twelve asthmatic subjects (mean age 23.3 years) exercised on three separate occasions, during which they all received combinations of disodium cromoglycate (DSCG) aerosol (10 mg) or placebo, both before and after exercise in a randomized double-blind study. There was a significant improvement in resting FEV1 in those subjects receiving DSCG before exercise compared with placebo (P less than 0.05). Following exercise there was a more rapid recovery of FEV1 in those receiving DSCG after exercise compared with placebo (P less than 0.005). The greatest differences in FEV1 between placebo and DSCG treated groups were seen in the first 20 minutes after receiving the drug in the post-exercise period. These findings suggest that DSCG has a significant bronchodilator effect.

Adolescent↗

Control of bovine parasitic gastroenteritis and parasitic bronchitis in a rotational grazing system using the morantel sustained release bolus.

Sixty cattle (12 first season and 48 second season grazing animals) were allocated to three groups according to age and bodyweight. Each group was divided into "control" and "treated" subgroups. Before turnout, a morantel sustained release bolus (MSRB) was administered to each animal in the "treated" category. The groups were moved from field to field according to the farmer's normal rotational grazing policy. Each field was, however, divided into two equal halves, one of which was reserved for the MSRB treated cattle, while the other was used exclusively for the controls. Severe parasitic gastroenteritis occurred in the first season controls during early September, while milder disease affected the untreated animals in the smaller of the second season groups. No gastrointestinal disease was apparent in the corresponding MSRB treated cattle. A mild outbreak of parasitic bronchitis occurred in the first year controls during October; there was evidence of less sever lungworm infection in the matching MSRB treated animals. The larger second season group showed no signs of parasitic disease.

Animal Husbandry↗

The proteinase-catalysed synthesis of peptide hydrazides.

1. We report the trypsin-catalysed conversion, in high yield, of peptides to peptide hydrazides, t-butyloxycarbonylhydrazides and phenylhydrazides. The substitution is at the alpha-carboxy group. 2. We discuss the relative merits of carrying out the conversion either simultaneously with tryptic cleavage of the parent protein or after such cleavage. 3. We report analogous results with chymotrypsin, elastase and subtilisin. 4. We propose the use of such products in protein semi-synthesis and in the preparation of specific proteinase inhibitors.

Catalysis↗