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Biomedical subjects

L S Jensen

Publications and source records attributed to L S Jensen.

At least 37 records · Page 2Linked to original sources
PubMed1995

Daily energy allotments and performance of broiler breeders. 2. Females.

Arbor Acres broiler breeder hens, 21 to 61 wk of age, were given the daily ME level recommended by the primary breeder for their age and level of production (100% AA) or were given 94 or 88% of that amount. The reduction in daily energy allotment had no effect on age at 50% or age at peak production, but there was a highly significant linear decrease in the eggs per hen from 165 +/- 2.8 in hens given 100% AA to 149 +/- 3.2 and 141 +/- 3.8 in hens given 94 and 88% AA. The percentage of nonlaying hens between 44 and 60 wk of age was substantially increased as daily energy allotment was reduced. The percentage settable eggs was significantly lower in the 100% AA group, but no differences in fertility or hatchability were seen. Chicks per hen fell from 123 +/- 2.4 to 116 +/- 2.4 to 102 +/- 2.6 as energy allotment was progressively reduced. Dietary energy allotment had no effect on egg weight, shell weight, shell characteristics, or proportion of albumen and yolk. Chick weight was unaffected but chicks' liver weight increased with increasing dam energy intake. Percentage lipid in hens' carcasses increased with increasing energy intake and percentage protein and percentage ash decreased.

Animals↗
PubMed1995

Preventive effects of recombinant human epidermal growth factor on the oesophageal epithelium in pigs subjected to sclerotherapy.

OBJECTIVE: To investigate the role of epidermal growth factor (EGF), a small (relative molecular mass 6000) polypeptide with mitogenic properties in the protection of gastrointestinal mucosal integrity. DESIGN: A prospective, randomized and blinded study. METHODS: Twenty-four minipigs with surgically induced portal hypertension underwent four consecutive weekly sessions of oesophageal sclerotherapy with 5 ml 1% polidocanol and were concomitantly treated with either a placebo or human recombinant EGF administered subcutaneously. Mucosal damage was evaluated on a weekly basis by endoscopic estimation of the size of the ulcerated area and by post-mortem morphometry. The EGF-induced morphological changes in the oesophageal epithelium were also evaluated histologically. RESULTS: In sclerosed and non-sclerosed parts of the oesophagus EGF significantly increased the thickness of the oesophageal epithelium (P < 0.03), but failed to reduce significantly the degree of oesophageal damage associated with sclerotherapy (P = 0.11). CONCLUSIONS: Systemic EGF treatment induces proliferation of the oesophageal mucosa, and EGF may therefore have the potential to reduce sclerotherapy-induced oesophageal damage.

Animals↗
PubMed1994

Systemic treatment with recombinant human epidermal growth factor accelerates healing of sclerotherapy-induced esophageal ulcers and prevents esophageal stricture formations in pigs.

Human epidermal growth factor (EGF), a small polypeptide (6 kDa) with mitogenic properties, has been implicated in the protection of gastrointestinal mucosal integrity. The efficacy of EGF in the prevention and healing of sclerotherapy-induced esophageal lesions was investigated in 24 minipigs with surgically induced portal hypertension. In addition, the effect of EGF on intragastric acidity and pharmacokinetics was investigated as possible means to explain its protective mechanism of action. The animals underwent three weekly sessions of sclerotherapy with polidocanol 2% and were concomitantly and for an additional three weeks treated with either placebo or EGF administered paravenously in the esophagus and/or subcutaneously. The subcutaneous treatment with EGF significantly (P < 0.05) reduced esophageal stricture and scar formations associated with sclerotherapy. Gastric pH values were significantly (P < 0.01) elevated only in animals receiving subcutaneous injections of EGF. Furthermore, the subcutaneous administration of EGF was associated with unexpected prolonged plasma concentration of the peptide. These results suggest a possible clinical value of EGF as an adjunctive treatment with the sclerotherapy.

Animals↗
PubMed1994

Recombinant human epidermal growth factor prevents sclerotherapy-induced esophageal ulcer and stricture formations in pigs.

Human epidermal growth factor (EGF), a naturally occurring protein, has been implicated in the protection of gastrointestinal mucosal integrity. The efficacy of EGF in the prevention of sclerotherapy-induced esophageal lesions was investigated in 18 minipigs with surgically induced portal hypertension. The animals underwent five weekly sessions of sclerotherapy with polidocanol 2% and were concomitantly treated with either placebo or EGF administered either paravenously or subcutaneously. EGF significantly (P < 0.05) reduced esophageal ulcerations, stricture formations, and mucosal histological damage associated with sclerotherapy. The drug was well-tolerated with no overt toxicity. These results suggest a potentially important clinical value of EGF as an adjunctive treatment with the sclerotherapy.

Animals↗
PubMed1993

[Blood transfusion increases the risk of surgical infection].

In a prospective randomized trial the frequency of infectious complications and natural killer cell function were investigated in 197 patients undergoing elective colorectal surgery and having either no blood transfusion (n = 93), transfusion with whole blood (n = 56), or filtered blood free from leucocytes (n = 48). Postoperative infections developed in 13 patients transfused with whole blood (23%), in one patient transfused with blood free from leucocytes (2%) and in two non-transfused patients (2%) (p < 0.01). Natural killer cell function was significantly (p < 0.001) impaired up to 30 days after surgery in patients transfused with whole blood. These data provide a strong case against the use of whole blood transfusion in patients undergoing elective colorectal surgery.

Adolescent↗
PubMed1993

Reduced plasma cholesterol and lipoprotein in laying hens without concomitant reduction of egg cholesterol in response to dietary sorbose.

Experiments were conducted to determine the effect of sorbose on feed consumption, egg production and size, and cholesterol metabolism of laying hens. In Experiment 1, 87-wk-old laying hens (10 per treatment) were fed diets containing 0, 10, or 20% sorbose for 4 wk. In a second experiment, 108-wk-old laying hens (eight per treatment) were fed a control diet, a diet with 10% added sorbose, or the control diet with intake restricted to the level of sorbose-treated hens for 4 wk. Feed consumption and egg production were recorded daily. Plasma and egg cholesterol levels were determined at 0, 2, and 4 wk. Plasma and egg very low density lipoprotein (VLDL) concentrations were determined after 4 wk. Egg production, feed intake, and body weight gain were significantly reduced by dietary sorbose. Egg and yolk weight and percentage yolk decreased in response to sorbose. Sorbose significantly reduced plasma cholesterol and VLDL by approximately 50%, compared with the hens fed a control diet. Egg cholesterol concentration (milligrams per gram of yolk) was significantly increased, although the reduction in yolk size resulted in similar total egg cholesterol (milligrams per egg). Restricting feed intake of laying hens significantly lowered plasma cholesterol, but not to levels comparable to that of sorbose-treated hens. The data indicate that substantial reduction of plasma cholesterol and VLDL by dietary sorbose was not accompanied by reduced egg cholesterol.

Animal Feed↗
PubMed1993

The hypocholesterolemic agent dichloroacetate increases egg cholesterol content of laying hens.

Experiments were conducted to determine whether a diet with added dichloroacetate (DCA), an inhibitor of cholesterol biosynthesis, would influence plasma and egg cholesterol concentrations when fed to laying hens. In the first experiment, 62-wk-old laying hens (10 hens per treatment) were fed a control diet containing 0, 350, 700, or 1,400 ppm DCA for an 8-wk period. Egg production and size, feed intake, weight gain, and plasma and egg cholesterol were determined at biweekly intervals. In a second experiment, 36-wk-old laying hens (eight hens per treatment) received diets with 0, 3,000, or 6,000 ppm added DCA for a period of 6 wk. Production parameters and cholesterol measurements were conducted as in Experiment 1. Egg production and feed intake were significantly decreased with increasing levels of DCA in Experiment 1. In the second experiment, 6,000 ppm DCA sharply reduced feed intake, body weight, and egg production. Yolk weight and percentage yolk were significantly decreased by the higher levels of DCA used in Experiment 2. Total plasma cholesterol was not affected by dichloroacetate in either of the experiments. In contrast, egg cholesterol concentration increased by 10 and 37% in Experiments 1 and 2, respectively, in response to diets with added DCA when compared with the unsupplemented controls. Total egg cholesterol increased in response to dietary DCA in Experiment 1, but not consistently in Experiment 2 due to the decreased yolk size of the hens fed DCA. The results of these studies indicate that dietary DCA was not effective in reducing egg cholesterol concentrations.

Animals↗
PubMed1992

Postoperative infection and natural killer cell function following blood transfusion in patients undergoing elective colorectal surgery.

The frequency of infection in 197 patients undergoing elective colorectal surgery and having either no blood transfusion, transfusion with whole blood, or filtered blood free from leucocytes and platelets was investigated in a prospective randomized trial. Natural killer cell function was measured before operation and 3, 7 and 30 days after surgery in 60 consecutive patients. Of the patients 104 required blood transfusion; 48 received filtered blood and 56 underwent whole blood transfusion. Postoperative infections developed in 13 patients transfused with whole blood (23 per cent, 95 per cent confidence interval 13-32 per cent), in one patient transfused with blood free from leucocytes and platelets (2 per cent, 95 per cent confidence interval 0.05-11 per cent) and in two non-transfused patients (2 per cent, 95 per cent confidence interval 0.3-8 per cent) (P less than 0.01). Natural killer cell function was significantly (P less than 0.001) impaired up to 30 days after surgery in patients transfused with whole blood. These data provide a strong case against the use of whole blood transfusion in patients undergoing elective colorectal surgery.

Adult↗
PubMed1992

Cholesterol concentration of egg yolk and blood plasma and performance of laying hens as influenced by dietary alpha-ketoisocaproic acid.

Experiments were conducted to determine the effect of supplemental alpha-ketoisocaproic acid (KIC) or Leu on layer performance and plasma and egg cholesterol levels. In the first experiment, 0, .09, or .27% KIC and .09 or .27% Leu were fed to 62-wk-old laying hens. In a second experiment, the same levels plus another level of .54% KIC and .54% Leu were fed to 32-wk-old hens for an 8-wk period. The basal diet or the basal diet supplemented with .27% KIC or .27% Leu were continued for 20 wk to determine the long-term effects of these supplements. In a third experiment, hens were fed 0, .1, .2, or .4% KIC for 8 wk. The addition of KIC and Leu to the hen diets did not affect percentage egg production, egg weight, shell thickness, or Haugh units. In Experiment 1, .27% KIC and .09% Leu significantly increased BW gain. Neither KIC or Leu significantly affected BW gain in Experiment 2 when measured at 8 or 28 wk. In the third experiment, diets supplemented with KIC increased significantly BW gain. In Experiment 1, .09% KIC and .09% Leu significantly reduced egg cholesterol at 4 wk. After 8 wk, .27% KIC reduced egg cholesterol significantly below the controls. No effect on plasma or egg cholesterol was observed in Experiments 2 and 3.

Animal Feed↗
PubMed1992

Research note: putrescine effects on performance of male broiler chicks fed low-protein diets supplemented with essential amino acids.

The purpose of the present study was to determine whether a polyamine deficiency could account for the reduced performance of broiler chicks fed a low-protein diet supplemented with several synthetic amino acids in comparison with those fed a more conventional CP concentration. Male broiler chicks were fed equicaloric diets calculated to contain 23, 20, or 17% CP. Each diet was supplemented with 0, .05, or .10% putrescine in a 3 x 3 factorial arrangement of treatments. Body weight gain of chicks fed the 17% CP diet was significantly (P less than .05) less than that of those fed the higher protein diets and feed conversion ratio significantly increased as the CP concentration decreased. Adding putrescine failed to significantly affect any of the parameters within each CP concentration. A deficiency of polyamines does not appear to explain the lower performance of broiler chicks fed low CP diets with added synthetic amino acids.

Amino Acids, Essential↗
PubMed1992

Influence of dietary taurine on performance and fat retention in broilers and turkey poults fed varying levels of fat.

Taurine, an amino acid synthesized from Met, primarily functions in bile acid conjugation. Four experiments were conducted to determine whether Tau supplementation of broiler cockerels and female turkey poults to 3 wk of age would influence performance and fat retention at different levels of dietary fat. In these experiments, Tau was added at 0 or .8% to a corn and soybean meal basal diet with dietary poultry fat added at 0, 5, or 10%. Taurine did not affect BW gain of broiler cockerels; however, in one experiment feed efficiency was improved (P less than .01) during the 1st wk and fat retention was improved (P less than .06) at 7 days of age. In experiments with turkey poults, dietary Tau did not affect weight gain but improved feed efficiency (P less than .01) during the 1st wk and decreased overall feed efficiency (P less than .01) in one experiment. Improvement of fat retention by Tau at 14 days was significant (P less than .02) in one experiment and approached significance (P less than .07) in the other experiment. Fat supplementation of both the broiler and turkey diets significantly (P less than .05) improved weight gain, feed efficiency, and fat retention. Supplementary Tau appears to have little effect on performance of broilers and turkeys.

Animal Feed↗
PubMed1992

Growth and tissue lipid deposition of broilers fed alpha-ketoisocaproic acid.

Dietary alpha-ketoisocaproic acid (KIC) was studied for effects on growth, feed efficiency, tissue cholesterol (TC) content, and immune response to a Newcastle disease virus (NDV) vaccination in broilers. In two experiments, broiler chicks were fed diets supplemented with graded levels of KIC to .54% of the diet. Feed efficiency, fat deposition, BW gain, and plasma cholesterol levels were determined at 3 wk. In a third experiment, broilers were fed diets supplemented with 0, .1, .2, and .4% KIC throughout the starter (0 to 3 wk), grower (3 to 6 wk), and finisher (6 to 7 wk) periods. Abdominal fat and plasma and breast TC were measured at 7 wk. In Experiment 4, levels of KIC to .6% were fed to broilers to determine TC content and to measure the immune response to NDV vaccination. Feed efficiency, BW gain, and percentage abdominal fat were not affected by KIC in any of the broiler experiments. The addition of KIC to broiler diets resulted in a significant reduction in breast (Pectoralis major) TC. Biceps (Biceps femoralis) TC, adductor (Pubo-ishio-femoralis) TC, and plasma cholesterol content was not affected by KIC. Geometric mean titers to NDV were not improved by KIC. The data indicate that KIC has no effect on growth or abdominal fat deposition, but may have a role in TC homeostasis.

Adipose Tissue↗
PubMed1991

A time-dependent study of passive esophageal wall properties and collagen content in rabbits with esophageal varices.

The passive biomechanical wall properties of the esophagus were studied in rabbits with esophageal varices and controls using a four-electrode impedance technique. Stepwise pressure inflation and deflation was done for analysis of esophageal cross-sectional area, compliance, and hysteresis monthly during six months. At sacrifice, the esophageal collagen content was determined. A small but statistically insignificant increase in compliance was observed during the six-month observation period in both groups. No differences were observed between the groups (P greater than 0.3). No change in hysteresis was observed in either group. The group with esophageal varices had significantly higher collagen content in the distal esophagus when compared to controls (P less than 0.05). No difference was demonstrated in the proximal part. No correlation was demonstrated between the collagen content and esophageal compliance. The study demonstrated that the method allows measurement of luminal cross-sectional area and tissue elasticity. No relationship was found, however, between the collagen content and compliance of the rabbit esophagus.

Animals↗
PubMed1991

Influence of orotic acid on performance, liver lipid content, and egg cholesterol level of laying hens.

Three experiments were conducted to determine the effects of dietary orotic acid (OA) on laying hen performance, liver lipid content, and plasma and egg cholesterol levels. Laying hens were fed a basal diet supplemented with 0, .5, 1.0, and 2.0% OA for 8 wk. Performance of the hens and cholesterol levels were measured at biweekly intervals. In all three experiments, OA decreased (P less than .05) BW in a linear manner. In two experiments, OA caused a linear decrease in total liver lipid (P less than .05), and in a third experiment OA resulted in a quadratic effect (P less than .01) on liver lipid content. There were no effects observed by OA supplementation on egg weight, yolk weight, percentage yolk, or egg production. Orotic acid failed to influence egg cholesterol content in any of the biweekly measurements of the three experiments. In two experiments, total plasma cholesterol content was not influenced by OA supplementation. Orotic acid significantly reduced (P less than .05) free and total plasma cholesterol in a third experiment when measured at Weeks 4, 6, and 8 of the experiment. The data indicate that OA is an ineffective dietary supplement for reducing egg cholesterol levels in laying hens.

Animals↗
PubMed1991

Effect of age of hen, egg weight, and sex on chick performance and lipid retention.

Experiments were conducted to determine whether age of hen, weight of the egg, and sex of the chick affected fat retention and growth of the broiler chick. Chicks were fed a corn and soybean meal diet containing 5% supplemental poultry fat. In the first study, eggs from two ages of hens were compared (30 and 52 wk) with six egg weight classes per age. The second experiment consisted of three hen ages (31, 37, and 47 wk) with three egg weight classes per age. The results indicated that as hen age and egg weight increased, BW gain of the chicks increased but feed efficiency and fat retention were not affected. Females had improved fat retention when compared with males. When analyzed within each egg weight class, there was no age effect on fat retention, BW gain, or feed efficiency.

Age Factors↗
PubMed1991

Influence of protein concentration, amino acid supplementation, and daily time to access to high- or low-protein diets on egg weight and components in laying hens.

Feeding a 13% CP diet based on corn and soybean meal and supplemented with methionine to laying hens results in reduced egg weight in comparison with hens fed a corn and soybean meal methionine-supplemented diet containing 16% CP. An experiment was conducted to determine whether the egg weight reduction could be eliminated by supplementing the low-protein diet with additional lysine, methionine, and tryptophan or by adding glycine and glutamic acid to increase the amino nitrogen to a level equivalent to 16% CP. The influence of the dietary treatments on the weight of the major egg components was also determined. In a second experiment, the influence of time of day of feeding the 13 or 16% CP diets on egg weight and egg components was determined. Adding additional amino nitrogen in the form of glycine and glutamic acid or increasing the levels of lysine, methionine, or tryptophan individually or in combination failed to prevent the depression in egg weight of hens fed the lower protein diet. Measurement of egg components demonstrated that the reduction in egg weight was primarily associated with a reduction in albumen content of the egg. Feeding a high-protein diet from 1400 to 0800 h and a low-protein diet from 0800 to 1400 h resulted in egg weight equivalent to that from hens continuously fed the high-protein diet. The lower weight of the albumen in eggs from hens fed a 13% CP diet may be due to a lower availability of amino acids for protein synthesis during the 3- to 4-h period when the ovum is in the magnum.

Amino Acids↗