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Biomedical subjects

M W McDonald

Publications and source records attributed to M W McDonald.

At least 19 recordsLinked to original sources
PubMed1992

Comparison between wheat, triticale, rye, soyabean oil and strain of laying bird on the production, and cholesterol and fatty acid contents of eggs.

1. The effects of feeding three types of cereal grain (wheat, triticale or rye) and soyabean oil (0 or 20 g/kg) over a 12-week period on the production, yolk cholesterol and yolk fatty acid concentrations of three strains of laying pullets were studied. 2. Pullets fed on wheat- or triticale-based diets had higher body weight gains, egg productions, egg weights, egg mass and lower yolk cholesterol concentrations than pullets fed on rye-based diets. However, there were no significant differences between the cereals in yolk cholesterol content. 3. There were no significant differences between the three cereals in total food consumption of pullets nor of yolk weight nor yolk concentration of palmitic, stearic and oleic acids. 4. Pullets fed on triticale-based diets had higher yolk linoleic acid concentrations and lower yolk oleic acid: linoleic acid ratios than pullets fed on rye- or wheat-based diets. 5. Soyabean oil supplementation increased egg production, egg mass, yolk linoleic concentration and yolk unsaturated to saturated fatty acid ratio, but reduced yolk oleic acid: linoleic acid ratio. 6. There were differences between strains of pullets in weight gain, food consumption, rate of lay, egg weight and yolk cholesterol, but not in yolk fatty acid concentrations. 7. It was concluded that wheat- or triticale-based diets gave good production of eggs of lower cholesterol content, that soyabean oil supplementation gave eggs with a high unsaturated to saturated fatty acid ratio and that two strains of layers produced eggs with lower yolk cholesterol concentrations than a third strain.

Animal Feed↗
PubMed1991

Effects of dietary calcium and available phosphorus concentration on digesta pH and on the availability of calcium, iron, magnesium and zinc from the intestinal contents of meat chickens.

1. The effects of high calcium intakes on the pH and availability of calcium, iron, magnesium and zinc in the gastrointestinal tract (GIT) contents of meat chickens were studied in two experiments. 2. A high dietary concentration of calcium (25.3 vs 10.7 g/kg) increased the pH of crop and ileum contents, but did not influence the pH of the contents of other segments of the GIT. 3. The solubilities of minerals in GIT contents were reduced and the size of dissolved mineral complexes were increased as the digesta moved from the duodenum and jejunum to the ileum. 4. After feeding diets with calcium and available phosphorus concentrations (15.3 and 4.3 g vs 21.8 and 4.3 g vs 22.6 and 8.3 g/kg), centrifugation of GIT contents showed that most (70-92%) of the calcium, iron, magnesium and zinc was in an insoluble form. High calcium diets reduced the proportion of soluble zinc associated with small complexes, and high calcium and available phosphorus diets reduced the proportions of soluble magnesium and zinc associated with small complexes. 5. These findings explain the mechanism of the reduced availability of zinc and magnesium in high calcium and high available phosphorus diets.

Animals↗
PubMed1991

The effects of dietary concentrations of minerals, source of protein, amino acids and antibiotics on the growth of and digestibility of amino acids by broiler chickens.

1. The effects of dietary calcium, available phosphorus, amino acid and antibiotic supplements on the digestibilities of amino acids and growth of broiler chickens were investigated in two experiments. 2. The performance of chickens fed on diets containing high concentrations of calcium and available phosphorus was poorer with meat meal-based diets than with soyabean-based diets. Methionine supplementation improved the performance of chickens fed meat meal-based diets. 3. A high dietary content of calcium (25.9 vs 11.8 g/kg) reduced chick performance and the digestibility of glutamic acid, leucine and phenylalanine but increased the digestibility of lysine and histidine. 4. High dietary contents of calcium and available phosphorus (24.3 and 13.0 vs 11.8 and 4.0 g/kg) reduced chick performance and the digestibilities of most amino acids. 5. Antibiotic supplementation did not improve the performance of chickens, but increased the digestibilities of most amino acids in chickens fed on diets with a high calcium or high calcium and available phosphorus contents. 6. It was concluded that excess dietary calcium alone, or calcium and phosphorus together, reduced chick performance and the digestibilities of most amino acids. Growing chickens tolerated excess dietary calcium and available phosphorus better in well-balanced amino acid diets, such as soyabean meal or methionine-supplemented meat meal diets, than in poorly balanced amino acid diets, such as unsupplemented meat meal diets.

Amino Acids↗
PubMed1991

The effects of dietary calcium, phosphorus, and protein on the performance and nutrient utilization of broiler chickens.

The effects of varying dietary Ca, available phosphorus (AP), and protein on 5- to 17-day performance (growth and feed efficiency), Ca and P contents of tibia and plasma, ME, and N utilization of broiler chickens were investigated in three experiments. In Experiment 1, high dietary Ca (24.3 versus 11.8 g/kg) reduced performance, N digestibility, and ME, whereas N retention was not affected. Reducing dietary protein (186 or 203 versus 217 g/kg) reduced performance and N retention but increased ME. In Experiment 2, high dietary Ca (25.3 versus 10.7 g/kg) reduced performance, tibia Ca, and plasma P and increased plasma total Ca; whereas the diet with both high Ca (25.3 g/kg) and high AP (9.8 versus 4.3 g/kg) reduced only performance. Reducing dietary protein from 206 to 166 g/kg diet reduced growth but improved feed efficiency and tibia P content. In Experiment 3, a diet containing 25.6 g of Ca and 4.9 or 10.7 g of AP compared with a diet containing 11.2 g of Ca and 4.9 g of AP/kg of diet reduced performance. Reducing dietary protein from 236 to 215 g/kg of diet decreased performance. It was concluded that high dietary Ca reduced growth performance and feed efficiency and that altering the dietary protein from 166 to 236 g/kg of diet did not overcome the growth depression effect of high Ca or of high Ca and AP diets.

Animals↗
PubMed1990

The effect of dietary calcium upon growth rate, food utilisation and plasma constituents in lines of chickens selected for aspects of growth or body composition.

1. The effect of increasing dietary calcium from 10.3 to 20 g/kg on 5- to 17-day growth performance and plasma minerals, electrolytes, total protein, albumin and glucose in chickens from 4 lines selected for: high 8-week body weight (W), low abdominal fat (L), high abdominal fat (F) or at random (C) was studied in two experiments. 2. High dietary calcium significantly reduced weight gain and plasma phosphate and potassium but increased food:gain ratio, plasma total calcium, glucose and albumin. 3. Significant correlations were found between plasma total calcium and plasma phosphate (r = -0.5, P less than 0.01), plasma total calcium and protein (r = 0.4, P less than 0.01) and between plasma total protein and albumin (r = 0.55, P less than 0.01). 4. Genotypes differed in their response to dietary calcium content. There was a substantial response in line F but little effect in line L. 5. In contrast to the three other lines, in line F high dietary calcium significantly increased plasma ionised calcium without altering plasma phosphate or total calcium concentration. 6. It was concluded that genetic selection has produced lines which vary in their tolerance to high dietary concentrations of calcium. Birds selected for increased fatness were less tolerant to high dietary calcium than their lean-selected counterparts.

Animals↗
PubMed1990

Effects of dietary calcium, available phosphorus and vitamin D on growth rate, food utilisation, plasma and bone constituents and calcium and phosphorus retention of commercial broiler strains.

1. The effects of different dietary concentrations of calcium (Ca), available phosphorus (AP) and vitamin D (D) on 5- to 16-day growth performance, and aspects of calcium and phosphorus (P) metabolism of chickens from three commercial strains were studied in two experiments. 2. Increasing dietary Ca reduced weight gain, tibia Ca and P content and increased plasma total Ca, Ca consumption and excretion, whilst dietary Ca at 32 g/kg increased tibia Ca:P ratio, plasma ionized calcium and reduced plasma P, tibia ash, P excretion, excreta moisture and Ca retention. 3. Increasing dietary AP reduced plasma total and ionized Ca and excreta moisture and increased P consumption and excretion, plasma P and tibia ash. 4. The addition of vitamin D increased plasma total and ionized Ca, tibia Ca:P ratio and reduced plasma sodium and P concentrations. 5. Strains differed in their tibia contents of Ca and Ca:P ratios, in response to Ca, AP and vitamin D diets whilst they differed in Ca excretion and excreta moisture caused by feeding either dietary Ca or AP. 6. It was concluded that dietary Ca, AP, vitamin D and strain of broiler chickens influenced the metabolism of Ca and P and that, as a consequence, the tolerance to high dietary Ca. A lean strain of chickens tolerated high dietary calcium better than its fat counterparts.

Animal Feed↗
PubMed1987

The partial dependency of human prostatic growth factor on steroid hormones in stimulating thymidine incorporation into DNA.

Growth factors stimulating DNA synthesis in mouse 3T3, human DU145, and LNCaP were partially purified from human benign hyperplastic and cancerous prostates. These factors have a high affinity for heparin sepharose and are eluted from the heparin-sepharose column, at 1.2 to 1.9 M NaCl. In normal prostates, the high affinity human prostatic growth factor occurred only in extremely small amounts. The high affinity growth factors stimulate DNA synthesis in 3T3, DU145, and LNCaP. Stimulation was significantly enhanced by 5 alpha-dihydrotestosterone and 17 beta-estradiol in the androgen sensitive LNCaP cell line. SDS-PAGE and isoelectrofocusing confirmed that the partially purified factors had a molecular weight of 18 kDa and acidic isoelectric points of pH 3.6 and 4.7.

Adult↗
PubMed1987

Renal transplantation in patients with indwelling continuous ambulatory peritoneal dialysis catheters.

Controversy exists regarding management of the continuous ambulatory peritoneal dialysis catheter in patients undergoing renal transplantation. We performed 30 transplants (23 cadaveric and 7 living related) in 27 patients with indwelling continuous ambulatory peritoneal dialysis catheters. Dialysis was necessary in the immediate post-transplantation period in 9 of 30 patients (30 per cent). Of these 9 patients 3 had temporary hemodialysis and 6 resumed continuous ambulatory peritoneal dialysis with the indwelling catheter. Two postoperative complications clearly were related to the continuous ambulatory peritoneal dialysis catheter: 1 patient required abdominal exploration for control of bleeding related to disruption of peritoneal adhesions at the time the continuous ambulatory peritoneal dialysis catheter was removed and 1 suffered an abscess at the catheter site 1 month after the catheter was removed. No patient experienced peritonitis during immunosuppression after transplantation. We support leaving the continuous ambulatory peritoneal dialysis catheter during and after transplantation to simplify pre-transplantation patient care and to avoid the possible need for temporary post-transplantation hemodialysis in many patients.

Abscess↗
PubMed1985

Adaptation of existing cutaneous ureterostomy for urinary drainage after renal transplantation.

We adapted existing cutaneous ureterostomies for urinary drainage in 3 patients who underwent renal transplantation. Careful preoperative radiological evaluation of the ureteral anatomy and appropriate preoperative planning are necessary for such patients. The concentration of serum creatinine was 0.9, 1.3 and 1.5 mg. per dl. at 2 months, 3 years and 10 years, respectively, after transplantation. All 3 patients have had bacteriuria that necessitated therapy with chronic suppressive antibiotics but clinical pyelonephritis has not occurred.

Adolescent↗
PubMed1985

Treatment of renal cell carcinoma by in situ partial nephrectomy and extracorporeal operation with autotransplantation.

During a 10-year period, 33 patients underwent in situ enucleation, in situ partial nephrectomy, or an extracorporeal operation for low-grade (1 or 2), low-stage (I or II), bilateral or solitary renal cell carcinoma. Only one patient (3%) (who had undergone in situ partial nephrectomy) had local recurrence; the projected 5-year rates of nonprogression of disease and survival from death due to cancer only were 76% and 87%, respectively. A group of patients who were closely matched for grade and stage of renal cell cancer underwent traditional transabdominal radical nephrectomy during the same time interval and had rates of nonprogression and survival similar to those of the conservative surgical group. Thus, in selected patients with low-grade, low-stage renal cell cancer, conservative surgical treatment (that is, renal parenchyma-saving procedures) can produce favorable results without the side effects (such as renal failure) associated with ablative renal operations.

Adult↗
PubMed1985

Quantitative review of optimum amino acid intakes for young laying pullets.

Data relating egg output to daily intakes of lysine, methionine, tryptophan, isoleucine and valine have been analysed using both published and unpublished sources. Amino acid requirements in mg/d for individual pullets were estimated by the following equations: (Table: see text) where E = egg output in g/d and W = body weight in kg. Response curves for flocks of pullets were calculated using the Reading model and optimum intakes were derived for various body weights, egg outputs and ratios of input costs to output values. Estimates of amino acid maintenance requirements were related to reported values for the adult cockerel and the amino acid requirement for egg output was related to the digestibility of amino acids and the composition of egg protein. Procedures are suggested for deriving response coefficients for other essential amino acids.

Amino Acids↗
PubMed1984

Testicular tumor in blacks.

Although testicular tumors are less common in blacks than in whites, they do occur and must be considered in making a differential diagnosis of scrotal masses. At The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston, 19 black men were treated for testicular tumor between 1944 and 1980, representing 1.4 per cent of the total of 1,380 patients treated for testicular tumor. Since blacks made up 7.9 per cent of all patients treated at UT M. D. Anderson Hospital, blacks with testicular tumor were seen about one-fifth as often as would be expected if there were no racial variation in the incidence of the disease. Twelve patients had a diagnosis of seminoma, five embryonal carcinoma, one teratocarcinoma, and one interstitial cell tumor. The majority of patients had metastatic disease at the time of diagnosis. Five of 12 patients with seminoma and 5 of 6 with nonseminomatous cancer died of disease. Prognosis today, however, is no worse for blacks than for whites.

Adult↗
PubMed1984

Improving results in primary diabetic renal transplantation.

One hundred seventeen patients with renal failure resulting from insulin-dependent diabetes mellitus received primary renal allografts from June 1970 to April 1983. Factors significantly associated with improved graft and patient survival were LRD sources (in particular, HLA-identical) and splenectomy. Variables such as transfusions, age, sex, and the administration of ALG were not significantly associated with transplant outcome. However, survival of patients and grafts has improved in recent years and continues to compare favorably with hemodialysis results. Although splenectomy might be the most important variable responsible for the improvement of our recent results, the use of ALG for rejection episodes might have contributed substantially to the improvement. Early transplantation, not analyzed in this study, might prove to be the most significant variable in the outcome of transplantation in patients with diabetic renal failure.

Adult↗
PubMed1983

The postabsorptive hydroxyproline in the long-term evaluation of patients with breast cancer.

The postabsorptive urinary hydroxyproline excretion test (Spot-HYPRO) was evaluated for its usefulness in reflecting the presence or absence of bone metastasis in 75 women with breast cancer. A comparison was made between the Spot-HYPRO values and bone disease, as documented by bone scanning supported by skeletal x-rays. Breast cancer patients with skeletal metastasis had 3-4-fold elevations in Spot-HYPRO above the control values (P less than 0.001). Mild elevations were noted in breast cancer patients without skeletal metastasis (P less than 0.025). Thirty patients received serial Spot-HYPRO and bone scans for 6 to 48 months (average, 24 months). There was a 90% correlation between changes in Spot-HYPRO and simultaneous changes on bone scan. Elevations in Spot-HYPRO preceded changes found on bone scan by an average of 3 months. The authors conclude that the Spot-HYPRO is a simple, convenient, and accurate method of documenting and following bone metastasis in patients with breast cancer.

Adult↗
PubMed1983

Measurement of progesterone receptor in human renal cell carcinoma and normal renal tissue.

Progesterone receptor was measured in eight samples of renal cell carcinoma, nine samples of normal renal tissue, and one sample of melanoma tissue. Progesterone receptor was identified in all samples, with the exception of one renal cell carcinoma. Three patients, all with receptor-positive tumors, were treated with medroxyprogesterone acetate for metastatic disease. In one of these patients there was a partial objective response to treatment. Further research regarding progesterone receptor in renal cell carcinoma is indicated.

Adenocarcinoma↗
PubMed1983

Leiomyosarcoma of the penis.

We report a case of an aggressive leiomyosarcoma of the penis treated with radical surgery, radiotherapy and chemotherapy. The patient died 7 months after diagnosis.

Humans↗