PubMed HealthSearch

Biomedical subjects

D Oreopoulos

Publications and source records attributed to D Oreopoulos.

13 recordsLinked to original sources

Effects of amino acid dialysate on appetite in CAPD patients.

The use of amino acid (AA) dialysate in CAPD patients may have theoretical disadvantages, since protein ingestion is known to suppress food intake in humans disproportionately to its energy value. Therefore we measured subjective appetite and food intake of CAPD patients in a cross-over study of 16 subjects (age 22-75 years, BMI 19-31, > 3 months on CAPD, non-diabetic and not protein malnourished). They received, in random order, either 4 weeks of dextrose only (their usual treatment), or one AA (1%) exchange replacing the first dextrose exchange each day. Subjective measurements of food intake (3 day food record) and quantitative measurements of lunch time food intake were obtained during a morning dextrose exchange after 28 days of each regimen. Except for a reduction in feelings of fullness during the AA treatment, there were no effects on feelings of hunger/satiety, food appeal, lunch-time food intake, or on 3-day food intake. We conclude that the use of a daily AA (1%) dialysate for 4 weeks does not affect subjective appetite or food intake of CAPD patients. There may even be a beneficial effect as the feeling of fullness decreased with the AA treatment.

Adult

Lymphatic removal of dialysate from the peritoneal cavity of anesthetized sheep.

Several investigators have suggested that the lymphatic circulation reduces ultrafiltration in continuous ambulatory peritoneal dialysis (CAPD). The purpose of this study was to assess lymphatic drainage of the peritoneal cavity directly in anesthetized sheep under dialysis conditions. Lymph was collected from the caudal mediastinal lymph node and the thoracic duct, both of which are involved in the lymphatic drainage of the ovine peritoneal cavity, and from the prescapular lymph node, which is not involved in peritoneal lymphatic drainage. Fifty ml/kg volumes of a mildly hypertonic dialysis solution (Dianeal 1.5%) containing 25 microCi 125I-human serum albumin were instilled into the peritoneal cavity, and lymph flows and the appearance of labeled protein in the lymphatic and vascular compartments were monitored for six hours. Following the instillation of dialysis fluid there was a tendency for lymph flow rates from the thoracic duct to increase but these changes were not significant. However, flow rates from the caudal lymphatic demonstrated significant increases, especially in the final three hours of the monitoring period. Only about 8% of the radiolabeled albumin was removed from the peritoneal cavity over six hours (that is, 92% was left in the peritoneal space). Of the albumin removed, approximately 17% of this was drained by abdominal visceral lymphatics into the thoracic duct. About 25% passed through the diaphragm into the caudal mediastinal lymph node and into efferent lymph. Since the efferent lymphatic duct of the caudal mediastinal node empties directly into the thoracic duct, about 42% of all protein removed from the peritoneal cavity of the sheep was ultimately transported to the thoracic duct.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Lymphatic drainage of the peritoneal cavity in sheep.

Lymphatic drainage of the peritoneal cavity has been investigated in anesthetized sheep. Studies involving intraperitoneal administration of a complex of Evans blue dye and bovine serum albumin demonstrated the existence of three anatomically distinct pathways. In the first pathway, dye is removed from the peritoneal cavity by diaphragmatic lymphatics that pass into caudal sternal lymph nodes. Efferent lymphatics from these nodes transport the material to cranial sternal lymph nodes. Efferent cranial sternal lymphatics then convey the material either directly or indirectly, via tracheal lymphatic trunks, to the right lymph duct. In the second pathway, the complex is transported from the peritoneal cavity by diaphragmatic lymphatics that pass into the caudal mediastinal lymph node. Efferent lymphatic ducts from this node transport the material to the thoracic duct. The third pathway appears to involve transport of the dye across the mesothelial lining of the abdominal viscera and removal from the interstitium by afferent visceral lymphatics. Material taken up in this manner is ultimately transported to the thoracic duct by efferent visceral lymphatics. Experiments involving measurements of lymphatic absorption of 125I-labeled human serum albumin from the peritoneal cavity indicated that, over the 6-h period studied, 4.55 +/- 1.20 and 1.43 +/- 0.56% of the injected tracer could be recovered in thoracic duct lymph and caudal mediastinal efferent lymph, respectively, and the sum of these values represented 26% of the recovered radioactivity. On the other hand, 16.95 +/- 6.93% of the injected radioactivity could be found in the blood over the same period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Measurement of free and free-plus-peptide hydroxyproline fractions in plasma.

Plasma hydroxyproline fractions--free-plus-peptide and free--were determined by a method involving centrifugal ultrafiltration and the procedure of Kivirikko et al. [Anal. Biochem. 19, 249 (1967)]. Within- and between-day precision (CV) for the combined fractions was 4--5% and 2.8--6%, respectively. Mean analytical recoveries of free hydroxyproline were 95.2% (87--109%) in the normal range, and 97% (91--108%) in the above-normal range. Normal ranges for plasma hydroxyproline fractions, based on data for 11 men and 19 women, were free-plus-peptide, 7.5--25.3; free, 4.9--22.7; and peptide (calculated), 0.1--5.1 mumol of hydroxyproline per litre, respectively. These ranges showed no sex-related differences and were gaussian in distribution. A factor was derived to transform data on concentrations in ultrafiltrate into plasma concentrations.

Humans

Partial body calcium measurements on patients with renal failure.

The bone calcium status of 39 patients with chronic renal failure on hemodialysis has been measured by in vivo neutron activation analysis (IVNAA) and reported in terms of a calcium bone index (CaBl) which relates the calcium in a patient to that in a normal person of the same height. In 20 of the 39 cases sequential measurements were made over periods of up to 40 mo. The results are compared with data obtained by radiology and by histological examination of bone biopsies. CaBl values varied from below normal to, in one case, above the range of normal. Many of the higher values were associated with demonstrable osteosclerosis. As found in previous work here with IVNAA, significantly low values of CaBl were associated with vertebral deformities; however, some patients with deformity had normal CaBl values, indicating that these had both local mineral loss (resulting in fracture) and osteosclerosis. Taken all together, the data suggest that more than half the patients have osteosclerosis. Sequential data showed no uniform response to treatment.

Adult

A controlled trial of nondrolone decanoate in the treatment of uremic anemia.

Thirty-seven male dialysis patients, from three university hospital centers known to have adequate iron B12, and folate stores, were entered into a controlled trial to study the effects of nandrolone decanoate (200 mg i.m. weekly) on their anemia. An initial six-month stabilization period was followed by a randomized 12-month study, with crossover between treatment and control groups occurring at six months. Patients received parenteral iron therapy plus oral folate throughout the trial. All serious illnesses or major blood losses excluded the patients from analysis. The 24 patients with remnant kidneys showed an increase in hemoglobin and hematocrit of 24% by the end of six months of treatment (P less than 0.005), with a corresponding decrement during the six months of control, but the five anephric patients showed no statistically significant change compared to those patients whose kidneys were in place during the study. Complications of treatment were minimal, with injection site hematoma the only significant local effect and a rise in triglyceride the only significant systemic disturbance. Despite the improvement in anemia, the disadvantages, including the high cost of treatment, the apparent plateauing of benefits by five months, the minimal subjective improvement in life style, the risk of i.m. injection, plus the long term effects of increased lipids, should limit this therapy to patients with remnant kidneys who have severe symptomatic anemia or frequent transfusion requirements.

Adult

Measurement of serum and plasma ionic calcium with the "Space-Stat 20 Ionized Calcium Analyzer".

Ca2+ was measured in sera and plasma from 36 normal subjects (18 men 23-57 years old, and 18 women 20-52 years old) with the Space-Stat 20 Ionized Calcium Analyzer. Within-day and between-day precision (CV) for commercial serum-based specimens varied from 0.64-0.96% and 1.1-3.8%, respectively, depending on their mean concentrations. Plasma and serum showed within-day CV's of 1.05 and 0.79%, respectively. The linear regression of serum Ca2+ (y) on plasma Ca2+ (x) was y = 0.63x + 0.45 mmol/litre with a highly significant (P less than 0.001) coefficient of correlation (r) of 0.69. An approximate 5% increase in the mean Ca2+ concentration in serum over that found in plasma is probably due to heparin complexing. No significant sex-related difference was observed for either serum or plasma. The mean Ca2+ concentration of 29 refrigerated specimens tended to decrease in seven days (by 2.3%, not statistically significant). The normal Ca2+ range in serum and plasma (n = 35) was 1.08-1.18 and 1.02-1.14 mmol/litre, respectively.

Adult

Platelet function in patients on long term peritoneal dialysis.

Platelet function studies were performed on 18 patients with end stage chronic renal failure receiving treatment by long-term peritoneal dialysis. The results of these studies were compared with previously reported data on healthy volunteers, non-dialyzed patients with chronic renal failure and patients treated by hemodialysis. Platelet adhesiveness was impaired and, unlike the other patient groups, there was no relationship between adhesiveness and serum creatinine. Platelet aggregation to both ADP and adrenaline chloride was normal, whereas marked impairment was seen in non-dialyzed patients with severe chronic renal failure and patients receiving hemodialysis. The results suggest that different uremic retention products affect these different phases in the platelet adhesion-aggregation reaction and that the peritoneal membrane is more permeable to that dialyzable factor which inhibits aggregation than conventional hemodialysis membranes. The studies are of interest both in consideration of adequacy of dialysis and in studies into the nature of the platelet defect in uremia.

Blood Cell Count

Serum ionic fluoride: normal range and relationship to age and sex.

We used the Orion fluoride electrode system to determine the normal range of serum ionic fluoride concentrations and to investigate its relationship to sex and age (A). 87 normal men, aged 18-92 years (mean, 46 years), and 49 normal women, age 19-64 years (mean, 38 years), participated in the study. At the 95% confidence limits, males less than 45 years old had a normal range of 0.29 to 1.52 mumol/litre and males greater than or equal to 45 years old 0.29 + 0.0101 (A-45) to 1.52 + 0.0101 (A-45) mumol/litre. Females, however, had a normal range of 0.022A - 0.32 to 0.022A + 1.07 mumol/litre. A group of 51 men 18-44 years old was compared with a group of 36 men 46-92 years old. The mean serum F- of the older group was shown to be significantly greater (P less than 0.01) than that of the younger group. Factors related to serum ionic fluoride values are (a) tea as an important source of dietary F-, (b) the lack of significant variation during daytime hours, and (c) the lack of significant difference in concentration between serum and plsma F-.

Adolescent