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Biomedical subjects

A J Lewis

Publications and source records attributed to A J Lewis.

At least 145 records · Page 8Linked to original sources
PubMed1985

Effect of source of dietary energy and energy restriction during lactation on sow and litter performance.

The effects of source of energy and energy restriction during lactation on sow and litter performance were investigated in an experiment with 90 primiparous sows. At parturition, the sows were randomly assigned to diets containing either tallow or cornstarch as a major energy source. Energy intake was restricted to 8 Mcal of metabolizable energy X sow-1 X d-1 during a 28-d lactation. All sows received equal amounts of crude protein, vitamins and minerals daily, which met or exceeded standard recommendations. Sows fed the diet with tallow lost more weight (P less than .05) during lactation than those fed the diet with cornstarch. Litter size at d 28 was greater (P less than .07) for sows fed cornstarch than for sows fed tallow. However, pig and litter weights on d 14 and 28 of lactation were similar between dietary treatments. Sows were bled on d 110 of gestation and d 14 and 28 of lactation and blood plasma was analyzed for urea. A significant treatment X time interaction was found for plasma urea. Sows fed the diet with tallow appeared to catabolize more protein than those fed the diet with cornstarch. Energy digestibility was lower (P less than .01) in the diet containing tallow, but protein digestibility was not affected by source of energy. Percentages of sows in estrus by 7, 14 and 70 d post-weaning were not different between treatments.

Animal Feed↗
PubMed1985

The nutritional value of normal and high lysine corns for weanling and growing-finishing swine when fed at four lysine levels.

One-hundred-ninety-two weanling pigs from two separate trials, (initial weight 6.0 and 5.6 kg) and 400 growing-finishing pigs (initial weight 17 kg) were fed normal and high lysine corn diets containing four levels of lysine in a 2 X 4 factorial arrangement. Crossbred (Large White X Landrace X Duroc) pigs were used in all experiments. The objectives of the experiments were to (1) compare normal and high lysine corn when fed at different lysine levels, (2) determine the lysine requirements for the three stages of growth and (3) evaluate the effect of protein level on the lysine requirement. All diets were balanced on a lysine basis. The results indicated that both weanling and growing-finishing pig performance and final carcass composition were similar for pigs fed normal or high lysine corn diets balanced on a lysine basis. Weanling pigs from 5 to 14 kg required at least 1.10% lysine. Based on changes in body weight gain and feed efficiency, the lysine requirement of growing pigs (17 to 54 kg) was .70%, and that of finishing pigs (54 to 101 kg) was .50%. However, based on lean tissue growth rate (as reflected by longissimus muscle area and percentage of lean in the carcass) the requirement was at least .75% during the growing stage and .60% during the finishing stage. The reduced protein level (2% lower) of the high lysine corn diets did not reduce the lysine required by pigs compared with those fed normal corn.

Animal Feed↗
PubMed1985

Weaning weight response of pigs to simple and complex diets.

Five experiments were conducted to determine (1) the value of simple vs complex diets on gains and feed conversion of pigs weaned at a constant age but varying in weight, (2) the optimum postweaning time to change from a complex to a simple diet and (3) the effect of previous treatment on subsequent performance. In the first experiment, pigs were weaned at 3 wk +/- 3 d and assigned within four weight groups (4.1, 5.0, 5.6 and 6.7 kg) to a simple or complex diet that was fed for 28 d. The complex diet improved (P less than .01) pig performance in all weight groups. As anticipated, the heavier pigs (5.6 and 6.7 kg) ate more (P less than .02) and grew faster (P less than .03) than did their lighter weight littermates (4.1 and 5.0 kg). The second experiment involved pigs weaned at 3 wk +/- 3 d that were assigned within two weight groups (4.4 and 6.6 kg) and fed a complex diet for 10 d, after which one-half of each weight group was switched to a simple diet. Pigs fed the complex diet for the entire 24-d period gained faster (P less than .05) and were more efficient (P less than .05) than those changed to the simple diet after 10 d. The heavier weight (6.6 kg) pigs ate more (P less than .02) and gained faster (P less than .02) than did the lighter weight (4.4 kg) pigs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1985

Effect of dietary fat on pig performance and dust levels in modified-open-front and environmentally regulated confinement buildings.

Four trials were conducted with 1,480 pigs (initial wt: 23 kg in trial 1,29 kg in trial 2 and 49 kg in trial 3 and 4) to determine the effect of dietary fat on pig performance, nutrient separation in an automated feed distribution system, dust levels in swine buildings and integrity of the respiratory system of swine. Two modified-open-front (B-1 and B-2) and two environmentally regulated (E-1 and E-2) growing-finishing buildings, of identical design, were used in each trial. In trial 1, 250 pigs (25 pens of 10 pigs/pen) in B-1 were fed a ground, mixed, corn-soybean meal diet (15% crude protein) with added tallow (5%), and 250 pigs in B-2 were fed the same diet but without added tallow. The assignment of diets to buildings were reversed in trial 2 in which 2.5% tallow was used instead of 5%. Each diet was fed ad libitum to pigs, and was distributed by an automated "Flexauger" system in trials 1 and 2. In each of trials 3 and 4, 120 pigs (12 pens of 10 10 pigs/pen) in E-1 were fed a corn-soybean meal diet (14% crude protein) with added tallow (5%) and 120 pigs in E-2 were fed the same diet but without added tallow. Overall, pigs fed the diet with tallow gained faster (P less than .002), consumed less feed (P less than .02) and converted feed more efficiently (P less than .002) than those fed the diet without tallow in trials 1 and 2. Pig performance was also improved by the addition of tallow to the diet in trials 3 and 4 (P less than .002). Crude protein, Ca, P and Cu contents of both diets were similar at each location sampled throughout the automated distribution system in trials 1 and 2. Addition of tallow to the diets reduced aerial dust levels, both with the feed distribution auger running (P less than .002) and without the auger running (P = .06) in trials 1 and 2. In trials 3 and 4, adding 5% tallow to the diet reduced aerial dust concentrations of of particle sizes of 14, 4, and 1.5 micron (P less than .002) and .4 micron (P = .07). The amount of settled dust was lower (P less than .001, trials 1, 3 and 4) when tallow was included in the diet.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Feed↗
PubMed1985

Effect of dietary energy intake during lactation on performance of primiparous sows and their litters.

A total of 146 primiparous sows was used in four replications of an experiment to investigate the effect of energy intake during a 28-d lactation on sow and litter performance. Dietary treatments consisted of three energy intakes; 10, 12 or 14 Mcal of metabolizable energy (ME) X sow-1 X d-1. All sows were fed equal amounts of crude protein, vitamins and minerals daily, which met or exceeded standard recommendations. The experiment was initiated at parturition. Sow weight and backfat loss during lactation decreased linearly (P less than .001) as energy intake increased. There were no differences in litter size at either 14 d of lactation or weaning. Pig weights on d 14 increased linearly (P less than .05) and litter weights tended to increase linearly (P = .13) as energy intake increased. At weaning, pig weights and litter weights increased (P less than .05) as sow energy intake increased. There were no significant differences in the percentages of sows in estrus by 7, 14, 21 and 70 d postweaning, but sows fed 10 Mcal ME/d had a slightly longer interval from weaning to first estrus than sows fed higher energy intakes. Serum urea concentrations of sows were inversely related to energy intake during lactation. Serum creatinine concentrations were not affected by energy intake. An intake of 10 Mcal ME/d by primiparous sows during a 28-d lactation resulted in reduced sow and litter performance; there was little difference between sows fed 12 and 14 Mcal ME/d.

Animals↗
PubMed1985

Immunomodulatory activity of Wy-18,251 (3-(p-chlorophenyl)thiazolo[3,2-a]benzimidazole-2-acetic acid).

The in vitro and in vivo effects of the experimental immunomodulatory agent Wy-18,251 (3-(p-chlorophenyl)thiazolo[3,2-a]benzimidazole-2-acetic acid) were studied in comparison with levamisole and indomethacin. Levamisole (4 mg/kg, i.v.) but not Wy-18,251 (less than or equal to 10 mg/kg, i.v.) enhanced carbon clearance rates in vivo in mice. Both Wy-18,251 and levamisole (100 mg/kg, p.o.) significantly suppressed the symptoms of experimental allergic encephalomyelitis (EAE) in rats injected with spinal cord emulsion, but neither were as effective as tilorone in this model. Wy-18,251 and levamisole (1-100 mg/kg, p.o.) suppressed the in vivo generation of plaque-forming cells (PFC) in mice immunized with sheep red blood cells while indomethacin (9 mg/kg, p.o.) enhanced PFC formation. All 3 agents (10(-5) - 10(-6) M) enhanced the in vitro ovalbumin (OA)-specific and Con A- or PHA-induced proliferative response and Con A-stimulated interleukin 2 (IL-2) synthesis of rat spleen cells. Furthermore, in vivo treatment of rats with 1-10 mg/kg (p.o.) of Wy-18,251 and levamisole but not indomethacin increased the subsequent in vitro mitogen or antigen (OA) responsiveness of spleen cells. None of the drugs (10(-5) - 10(-7) M) influenced the natural killer cell (NK) activity of rat spleen cells when incorporated directly into the 51Cr release NK assay.

Animals↗
PubMed1985

Transorbital intracavernous needle biopsy in painful ophthalmoplegia. Case report.

Painful ophthalmoplegia due to lesions in the region of the anterior cavernous sinus and superior orbital fissure may elude early diagnosis. Principal disease categories to be considered in patients with this complaint are neoplasm, vascular lesion, and inflammation. Although high-resolution computerized tomography (CT) may be helpful, definitive diagnosis frequently requires histological examination of tissue. In suitable patients this may be obtained by transsphenoidal or orbital biopsy. The orbital fine-needle aspiration technique has been recommended, but experience with this method is limited, and a definitive diagnosis cannot always be reached. The authors have established that, in suitable patients, the fine-needle aspiration technique with CT guidance may also be employed safely and effectively for lesions of the anterior cavernous sinus.

Aged↗
PubMed1985

Subdural meningioma of spinal cord. Case report.

A case of extensive circumferential meningioma of the spinal subdural space is reported. A potential mechanism for this growth pattern is proposed, and preoperative diagnosis by computerized tomography is discussed. This case reinforces the necessity for intradural exploration when an expected extradural neoplasm is not encountered at operation.

Adult↗
PubMed1985

Primary meningioma of the nasopharynx: case report and review of ectopic meningioma.

Meningiomas not uncommonly spread outside the central nervous system, but primary extracranial meningiomas are much less common, the sites described including the orbit, the calvarium, the neck, the temporal bone and the paranasal sinuses. Reported here is the first instance of extracranial meningioma of the nasopharynx. The histological appearance of meningiomas is diverse, and in ectopic sites can be mistaken for malignant epithelial tumors, as happened here initially. The tumor was excised via a transpalatal flap using an intracapsular debulking approach borrowed from the armamentarium of the intracranial surgeon. Prolonged follow-up with interval CT scans are recommended in patients with apparent ectopic meningioma, in case undemonstrable intracranial disease later becomes manifest.

Biopsy↗
PubMed1984

Effect of forskolin on prostaglandin synthesis by mouse resident peritoneal macrophages.

The relationship between cyclic 3',5'-adenosine monophosphate (cAMP) and prostaglandin (PG) synthesis was investigated in the mouse resident peritoneal macrophage. Macrophages were established as monolayer cultures in petri dishes. After addition of various agents, culture media and cells were removed for PG and cAMP analysis by standard radiochromatographic techniques and radioimmunoassay respectively. Forskolin, a potent receptor-independent adenylate cyclase activator, rapidly increased cAMP synthesis within 5 min in a dose related fashion in both non-treated macrophages and macrophages treated with 12-O-tetradecanoylphorbol-13-acetate (TPA). Furthermore, forskolin markedly reduced both 6-keto-PGF1 alpha and PGE2 synthesis induced by TPA and this inhibition was inversely correlated with increases with cAMP generation. In contrast, cholera toxin failed to mimic the inhibitory action of forskolin on PG synthesis even though it induced similar increases in cAMP; however this increase was only evident after a lag period of at least 1 h. Additionally, forskolin, but no cholera toxin inhibited PG synthesis and zymosan phagocytosis when these cells were activated with zymosan particles. These observations, therefore, suggest that a rise in cAMP is not always correlated with a reduction in PG synthesis.

Animals↗
PubMed1984

Bronchodilating activity of forskolin in vitro and in vivo.

The effect of forskolin, a receptor-independent adenylate cyclase activator on acetylcholine (ACh)-, histamine- and leukotriene D4 (LTD4)-induced contractions in isolated tracheal spirals was investigated. Forskolin reduced the contraction due to these agonists (IC50S: ACh 5.8 X 10(-6) M; histamine 4 X 10(-7) M; LTD4 3.1 X 10(-6) M). Forskolin was also effective against ACh- and histamine-induced contraction when added during contraction. In ovalbumin-sensitized guinea pigs, intravenously and intraduodenally administered forskolin significantly reduced the bronchospasm due to aerosol administration of ovalbumin. These results suggest that forskolin could prove useful in delineating the role of cyclic nucleotides in pulmonary smooth muscle responses.

Acetylcholine↗
PubMed1984

Rebound nystagmus in olivocerebellar atrophy: a clinicopathological correlation.

Rebound nystagmus was recorded in a patient with cerebellar dysfunction. Neuropathological examination showed degeneration of the inferior olivary nuclei and the cerebellar cortex. The basis pontis and the brainstem tegmentum were spared. Rebound nystagmus is attributed to a smooth eye movement bias that is generated within intact vestibuloocular pathways to oppose gaze-evoked centripetal drift of the eyes. The source of the rebound bias was not visual, because rebound nystagmus normally occurs in darkness, smooth pursuit was paretic, and the olivocerebellar visual relay pathway was degenerated. An extraretinal, efference copy signal of the eye position error must detect the ocular drift and generate the rebound bias. The neuropathological findings indicate that rebound nystagmus can be a sign of involvement confined to the olivocerebellar circuit and that nonvisual signals of eye position are monitored independently of this cerebellar system.

Aged↗
PubMed1984

Differential effects of putative lipoxygenase inhibitors on arachidonic acid metabolism in cell-free and intact cell preparations.

The effects of nordihydroguairetic acid (NDGA), 3-amino-1-trifluoromethyl-)-phenyl-2-pyrazoline (BW755c), eicostatetraynoic acid (ETYA), phenidone, quercetin, and indomethacin (INDO) on the synthesis of 15-hydroxyeicosatatetraenoic acid (15-HETE) from soybean 15-lipoxygenase, leukotriene B4 (LTB4) from 5-lipoxygenase, and prostaglandin E2 (PGE2) from cyclooxygenase enzymes of rat neutrophils and mouse peritoneal macrophages were investigated. All of the drugs caused a dose-related inhibition of increased oxygen consumption by soybean 15-lipoxygenase in the presence of arachidonic acid and the rank order of potency was phenidone greater than or equal to BW755c greater than ETYA greater than quercetin greater than NDGA greater than indomethacin. The reduction in oxygen consumption correlated with a reduction of 15-HETE formation as identified by high-performance liquid chromatography. Apart from indomethacin, these drugs were also effective against the rat neutrophil 5-lipoxygenase, although the rank order of potency did not correlate with that obtained with soybean 15-lipoxygenase. Furthermore, in both A23187-activated rat neutrophils and zymosan-activated mouse peritoneal macrophages the synthesis of prostaglandins was inhibited by all of these drugs. In the neutrophils, the rank order of potency was INDO greater than ETYA greater than BW755c greater than quercetin greater than NDGA greater than phenidone, whereas in mouse peritoneal macrophages, the order was INDO greater than ETYA greater than BW755c greater than NDGA greater than quercetin greater than phenidone. These results suggest that putative lipoxygenase inhibitors exhibit both qualitative and quantitative differences in their effects on both lipoxygenases and cyclooxygenases.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1984

The effects of antiallergic and bronchodilator drugs on platelet-activating factor (PAF-acether) induced bronchospasm and platelet aggregation.

Platelet activating factor (PAF-acether) is a potential mediator of asthma and inflammation. Recently, the suggestion was made that inhibition of PAF-acether by disodium cromoglycate (DSCG) might be partly responsible for the effectiveness of DSCG in asthma. We have extended these studies and examined the effects of antiallergic and bronchodilator drugs on PAF-acether induced bronchospasm after i.v. administration in guinea pigs and in vitro platelet aggregation in rabbits. Neither DSCG nor Wy-41,195, a potent orally effective antiallergic, altered either of the PAF-acether responses. Furthermore, aerosolized ipratropium, promethazine, ketotifen and FPL 55712 failed to affect the PAF-acether-induced bronchospasm. The same drugs were also ineffective against platelet aggregation induced by PAF-acether. In contrast, aerosolized thiazinamium chloride inhibited the bronchospasm and also inhibited PAF-acether-induced platelet aggregation. Thiazinamium chloride possessed weak antiaggregatory effects against ADP and was without effect against arachidonic acid-induced platelet aggregation. Both lipoxygenase and cyclooxygenase products of arachidonic acid metabolism appear to be involved in PAF-acether bronchospasm since i.v. administered lipoxygenase inhibitors (phenidone, BW755c and NDGA) and indomethacin independently inhibited this in vivo response. However, these drugs failed to alter platelet aggregation to PAF-acether. Thiazinamium chloride may be capable of directly antagonizing the PAF-acether-induced platelet aggregatory response and, in addition, inhibiting the synthesis and/or effects of bronchoconstrictor amines and endogenously generated arachidonic acid metabolites.

Animals↗
PubMed1984

A comparative study of the antiinflammatory activity of fentiazac and its major metabolite, p-hydroxy fentiazac.

Wy-25,110, the p-OH metabolite of fentiazac was approximately 100 times less potent than fentiazac after oral administration in rat carrageenan edema and 100-130 times less potent as an inhibitor of prostaglandin synthesis by mouse peritoneal macrophages. In addition, Wy-25,110 was one twelfth as active as fentiazac against immunologic-induced inflammation on day 16 in rat adjuvant arthritis. Wy-25,110 was also much less potent than fentiazac when administered intravenously, suggesting that inadequate oral absorption does not account for its lack of potency. Thus it seems unlikely that the p-OH metabolite contributes greatly to the antiinflammatory properties of fentiazac.

Acetates↗
PubMed1984

The antiinflammatory profile of (5H-dibenzo[a,d]-cyclohepten-5-ylidene)acetic acid (WY-41,770), an agent possessing weak prostaglandin synthetase inhibitory activity that is devoid of gastric side effects.

Wy-41,770 [(5H-dibenzo[a,d]cyclohepten-5-ylidene)acetic acid], a novel acrylic acid, was compared to indomethacin and aspirin in standard antiinflammatory, analgesic and antipyretic animal models. The acute antiinflammatory, analgesic and antipyretic activity of Wy-41,770 (oral ED50S 50-170 mg/kg) was similar to aspirin; however, it was considerably more potent orally in adjuvant arthritis in the rat (ED50, 16 mg/kg) and urate-induced synovitis in the dog (ED50, 4.5 mg/kg). Wy-41,770 was a weak inhibitor of prostaglandin biosynthesis and did not inhibit either 5- or 15-lipoxygenase. Furthermore, the cellular migration characteristic of carrageenan pleurisy was not affected by Wy-41,770. Unlike a majority of NSAIDs, it produced no gastric irritation in rats after either acute or chronic oral administration over the range 400-800 mg/kg. The major mechanism of action of Wy-41,770 has yet to be identified but does not seem to involve interference of arachidonic acid metabolism.

Acetates↗
PubMed1984

The absence of antibodies to type II collagen in established adjuvant arthritis in rats.

Utilizing an adjuvant arthritis model in rats, we examined humoral immunity to collagen and inflammation in animals with active disease and during drug therapy. Humoral immunity to types I or II collagen was not detected in the sera of rats with advanced adjuvant arthritis; this was in marked contrast to rats with type II collagen-induced arthritis which possessed serum antibodies to native and denatured type II collagen. Hind paw edema and bone pathology were monitored as parameters of inflammation. A new investigational drug, Wy-41,770, was most effective in reducing all of these aspects of inflammatory disease while indomethacin, methylprednisolone, and D-penicillamine caused a less significant diminution of only some of these parameters of inflammation. Antibodies to collagen were not detected in the sera of rats treated with the drugs under study. These data demonstrate that adjuvant arthritis can occur in rats in the absence of antibodies to types I or II collagen.

Animals↗