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Biomedical subjects

R M Jordan

Publications and source records attributed to R M Jordan.

At least 19 recordsLinked to original sources
PubMed1991

Fish meal as a protein supplement in finishing lamb diets.

An in situ protein degradation trial and two growth trials were conducted to evaluate the use of fish meal (FM) as a protein supplement in feeder lamb diets. Finn cross and Hampshire lambs were given ad libitum access to corn diets, minerals, and water. In Growth Trial 1, four isonitrogenous (12.6% CP on a DM basis) and isocaloric (77% TDN) diets were supplemented with the following: a) 100% soybean meal (SBM); b) 70% SBM + 30% FM; c) 40% SBM + 60% FM; and d) 100% FM on a DM basis. Diets were fed to 144 lambs for 56 d in a randomized complete block (initial BW) design. In Growth Trial 2, four diets were fed to 80 lambs for 42 d in a completely randomized design with treatments arranged as a 2 x 2 factorial. Main effects in Growth Trial 2 were dietary CP level (13.3 or 14.9%) and source (SBM or SBM + FM). Alfalfa hay was used as the roughage part of each diet. In situ CP degradation (determined in cattle) of SBM, FM, and corn fed in both growth trials were 77.8, 52.3, and 56.8%, respectively. In neither growth trial was ADG affected (P greater than .05) by dietary CP source. Lambs gained faster (P less than .05) when the CP level was increased from 13.3 to 14.9% in Growth Trial 2. In both trials, protein efficiency ratio (grams of gain/grams of protein intake) and energy efficiency ratio (grams of gain/kilograms of TDN intake) were not different (P greater than .05) among diets. Because of the low ruminal degradation of corn protein, the relative value of SBM and FM in full-fed, high-corn diets was comparable.

Animal Feed↗
PubMed1991

Influence of dietary protein and carbohydrate sources on nitrogen metabolism and carbohydrate fermentation by ruminal microbes in continuous culture.

Four diets containing 15% CP were formulated to study the effects of dietary carbohydrate and protein sources on N metabolism and carbohydrate fermentation by ruminal bacteria. Diets were supplied to eight dual-flow continuous culture fermenters during three experimental periods in a randomized complete block design. Six replications were obtained for each diet. Treatments were arranged as a 2 X 2 factorial with two carbohydrate and two protein sources. Carbohydrate sources were corn and barley and protein sources were soybean meal (SBM) and fish meal (FM). Approximately 40% of the dietary CP was derived from SBM or FM and corn or barley provided 39% of dietary DM. All diets contained 15% grass hay, 20% wheat straw, and 10.1 to 15.3% solka floc (DM basis). Interactions (P less than .05) were observed between dietary carbohydrate and protein sources, resulting in a depression of VFA production (moles/day) and digestion (percentage) of ADF and cellulose when the corn-FM diet was fed. True OM digestion (percentage) was higher (P less than .05) for SBM than for FM diets and for corn than for barley diets. Although dietary CP degradation (percentage) was higher (P less than .05) for SBM than for FM diets, non-NH3 N in the effluent (grams/day) was not different among diets due to a greater (P less than .05) bacterial N flow for SBM than for FM diets. Despite the lower amino acid (AA) intake (P less than .05) for corn than for barley diets and also for FM than for SBM diets, flows (grams/day) of total AA, essential AA (EAA), and nonessential AA (NEAA) were similar (P greater than .05) among diets. However, greater (P less than .05) total AA, EAA, and NEAA flows (percentage of AA intake) were found for corn than for barley diets and for FM than for SBM diets. It is concluded, therefore, that ruminal escape protein derived from corn or FM has a significant effect on manipulating AA leaving the ruminal fermentation.

Amino Acids↗
PubMed1991

Ruminal protein metabolism and intestinal amino acid utilization as affected by dietary protein and carbohydrate sources in sheep.

Eight wether lambs fitted with ruminal, duodenal, and ileal cannulas were used in a replicated 4 x 4 Latin square design to study the effects of carbohydrate and protein sources on ruminal protein metabolism and carbohydrate fermentation and intestinal amino acid (AA) absorption. Treatments were arranged as a 2 x 2 factorial. Carbohydrate sources were corn and barley; protein sources were soybean meal (SBM) and fish meal (FM). Diets contained 15.5% CP, of which 40% was supplied by SBM or FM. Corn or barley provided 39% of dietary DM that contained equal amounts of grass hay and wheat straw. Fish meal diets produced a lower (P less than .05) ruminal NH3 concentration and resulted in less CP degradation and bacterial protein flow to the duodenum than did SBM diets. Replacing SBM with FM increased (P less than .05) ruminal digestion of all fiber fractions. In addition, cellulose and hemicellulose digestibilities in the rumen tended to increase (P greater than .05) when barley replaced corn in the FM diets. Carbohydrate x protein interactions (P less than .05) were observed for OM digestion in the rumen and AA absorption in the small intestine (percentage of AA entering); these interactions were highest for the barley-FM diet. These results suggest that feeding FM with barley, which is high in both degradable carbohydrate and protein, might benefit ruminants more than feeding FM with corn, which is high in degradable carbohydrate but relatively low in degradable protein.

Amino Acids↗
PubMed1991

Fish meal as a protein supplement in ruminant diets: a review.

Fish meal (FM) as a protein supplement in ruminant diets is presented to illustrate production responses to FM supplementation and to explain the possible factors that may affect the magnitude of these responses. Positive responses are consistently detected when FM is fed to nonruminants, but the responses when fed to ruminants have lacked consistency. Research indicates that ruminal protein degradation of FM is affected by processing factors including type and freshness of fish, addition of preservatives, stabilization of fat, type of dryer used, temperature and duration of heating, and the amount of fish solubles added back to the meal. Performance data published in the last two decades have been categorized into body weight gain and milk yield and composition. Fish meal was more effective in improving body weight gain in young than in finishing ruminants and in males than in females or castrated males. Daily gains and feed efficiencies were higher when FM supplemented medium- or poor-quality silages than when it was added to high-quality silages. No significant advantage was found for replacing protein sources that were highly ruminally degradable with FM in high-corn diets fed to growing ruminants. Milk yield and milk protein concentration were improved by FM supplementation of low-concentrate diets fed to cows in early lactation. However, milk fat percentage was negatively affected by FM supplementation. Reproduction data indicated that body gain and conception rates of high-producing cows were improved by supplementing their diets with FM during early lactation. Results suggest a significant advantage of FM supplementation to ruminant diets if the physiological status of the animal and the quality of the dietary ingredients are taken into account.

Animal Feed↗
PubMed1987

Giant invasive prolactinomas.

Two of the largest prolactinomas ever documented that have been followed for nine and 10 years, respectively, demonstrate how aggressive prolactinomas may become and how difficult invasive prolactinomas are to treat. One of these prolactinomas invaded both internal auditory canals and simultaneously grew inferiorly, reducing the bony support of the skull and necessitating the patient to utilize both hands to hold his head up. The second patient's prolactinoma invaded the sphenoidal, ethmoidal, and cavernous sinuses. Both of these patients had neurosurgical debulking of their tumors followed by radiation therapy. Neither patient's prolactin levels decreased significantly during their first five years post-surgically, at which time bromocriptine was added. Since then, there has been a gradual lowering of serum prolactin levels and a decrease in the size of these tumors. These cases demonstrate that prolonged treatment and very large doses of bromocriptine may be necessary for tumor reduction in patients with invasive prolactinomas.

Adult↗
PubMed1986

Bovine lens aldehyde dehydrogenase: activity and non-linear steady-state kinetics.

Bovine lens aldehyde dehydrogenase is located predominantly in the cortical and nuclear regions, although the specific activity is highest in the epithelial cells. A novel two-step procedure has been used to purify aldehyde dehydrogenase from bovine lens to homogeneity. A comparison using published assay methods for aldehyde dehydrogenases showed that the dimeric lens enzyme had the highest specific activity of any cytoplasmic aldehyde dehydrogenase, although the kcat value was not exceptional. Computer curve-fitting showed that the minimum degree of the rate equation with propionaldehyde and acetaldehyde as substrates was 2:2. The relationship (a2 X b1)/(a1 X b2) was used to show the marked effect of temperature, and to a lesser extent pH, on the non-linear steady-state kinetics. These results indicate that the rate-determining step at low aldehyde concentrations (probably aldehyde binding) is accelerated by increasing temperature to a much greater degree than the rate-determining step at high aldehyde concentration (probably NADH release).

Acetaldehyde↗
PubMed1986

Conversion of CSF monomeric growth hormone to large growth hormone with exposure to serum.

We have found a dissociation between CSF and serum growth hormone heterogeneity in a patient with suprasellar extension of a growth hormone-secreting pituitary tumour. When CSF was studied using gel chromatography, virtually all the growth hormone eluted as monomeric growth hormone with only 2.4% eluting before albumin as large growth hormone ('big, big' growth hormone). In contrast, the large component comprised 15.4% of the total immunoreactivity in simultaneously obtained serum. When the CSF specimen was incubated with growth hormone-poor serum, the elution pattern changed remarkably with 16% of the total immunoreactivity eluting as large growth hormone causing it to resemble the serum elution pattern. We also measured growth hormone heterogeneity in the inferior petrosal vein (a site very close to pituitary venous drainage) during inferior petrosal venography in 3 patients. As the growth hormone concentration increased, the percentage eluting as monomeric growth hormone increased, whereas that eluting as large growth hormone decreased. When the growth hormone concentration fell towards baseline, the percentage of growth hormone eluting as monomeric growth hormone fell while that eluting as large growth hormone increased. Thus, our studies suggest that large growth hormone results from binding of monomeric growth hormone to serum proteins or aggregation of monomeric growth hormone in the presence of protein. Our studies also show that when blood is sampled at a site close to the pituitary, the growth hormone is released primarily as monomeric growth hormone.

Blood Proteins↗
PubMed1985

Hyperalimentation as cause of markedly worsened metabolic control in a patient with autoantibodies to the insulin receptor.

Patients with type B insulin resistance and acanthosis nigricans have autoantibodies to their insulin receptors and usually have signs and symptoms of other autoimmune diseases. The first case demonstrating that hyperalimentation markedly disturbs blood glucose control in type B insulin-resistant patients is described. Neither prednisone, insulin (up to 240 units per hour), nor tolbutamide appeared to help this patient's metabolic control. After the addition of cyclophosphamide for one week, the anti-insulin receptor autoantibody titer dropped from greater than 1:1,000 to 1:1. Six months later, the patient had a complete remission, which is rare, with only three other reported remissions in these patients with type B insulin resistance.

Acanthosis Nigricans↗
PubMed1985

Human prolactin heterogeneity in pituitary effluent blood.

We have used column chromatography to study prolactin (PRL) heterogeneity in plasma obtained from the inferior petrosal vein, a sampling site very close to the anterior pituitary gland. Blood specimens were obtained from four hyperprolactinemic subjects over varying time intervals during inferior petrosal vein venography. All patients demonstrated an increase in PRL secretion during the sampling period which was presumably secondary to the mild stress of the procedure. In each study subject there was an increase in the percent and amount of PRL secreted as small PRL (peak III) as the PRL concentration in the inferior petrosal vein increased to a maximum. The percent secreted as intermediate PRL (peak II) fell while the amount either remained constant or increased slightly. The percent and amount eluting as large PRL (peak I) was small and unchanging in patients 1, 2 and 3, despite the increase in total PRL concentration. Patient 4 had an unusual elution pattern in which the 0 minute specimen contained predominantly large PRL. As the total PRL concentration increased the percent and amount eluting as small PRL dramatically increased while the percent eluting as large PRL fell in proportion to the increase of small PRL. Intermediate PRL was virtually absent in this patient. Thus, this study indicates that the increase in PRL concentration during a secretory pulse is primarily from small PRL while the contributions of large and intermediate PRL are modest and variable.

Adult↗
PubMed1979

Medullary sponge kidney and renal-leak hypercalciuria. A link to the development of parathyroid adenoma?

The pathogenesis of the association of medullary sponge kidney and hyperparathyroidism from parathyroid adenoma remains obscure. This unusual case of medullary sponge kidney and secondary hyperparathyroidism due to renal-leak hypercalciuria gives insight into a possible mechanism for the occurrence of medullary sponge kidney with parathyroid adenoma. Suppressible hyperparathyroidism due to renal calcium wasting could represent an intermediate stage in the development of unsuppressible parathyroid hormone secretion. Thus, parathyroid adenoma occurring with medullary sponge kidney may represent a consequence of disordered renal calcium excretion rather than a primary abnormality.

Adenoma↗
PubMed1979

Alcohol-induced Cushingoid syndrome.

A 35-year-old woman with alcoholic liver disease presented with physical stigmas and laboratory confirmation of Cushing's syndrome. With discontinuance of alcohol, her signs of Cushing's syndrome resolved and the urinary free cortisol and the urinary 17-hydroxycorticosteroid response to dexamethasone returned to normal. These findings broaden the spectrum of deranged glucocorticoid chemistry that can occur in alcohol-induced cushingoid syndrome.

Adult↗
PubMed1979

Alternating atrial and ventricular tachycardia.

A patient with alternating atrial and ventricular tachycardia is described. He had an acute myocardial infarction and was taking digitalis. The atrial tachycardia, which was occasionally associated with aberrant ventricular conduction, was able to interrupt the ventricular tachycardia though the reverse was not true, suggesting a retrograde conduction block. This patient shows that atrial and ventricular arrhythmias can alternate and, since tachycardia with aberrant ventricular conduction can closely resemble ventricular tachycardia, intra-atrial electrocardiography may be necessary to establish an accurate diagnosis.

Digoxin↗
PubMed1979

Nelson's syndrome and spontaneous pituitary tumor infarction.

Large, adrenocorticotrophic hormone-secreting pituitary tumors (Nelson's syndrome) developed in four of 12 patients treated with a bilateral adrenalectomy for Cushing's disease. Two of the patients with Nelson's syndrome suffered spontaneous pituitary tumor infarctions. One patient improved under close observation and subsequent radiation therapy, although she ultimately died from her locally invasive tumor. The condition of the other patient-which had stabilized-appeared to be worsened by surgical intervention. The high incidence of these tumors after bilateral adrenalectomy, their large and agressive nature, and their apparent propensity to undergo spontaneous infarction supports the position that initial therapy for Cushing's disease should be directed to the pituitary gland.

Adrenalectomy↗