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N J Stone

Publications and source records attributed to N J Stone.

51 records · Page 3Linked to original sources
PubMed1981

Hemodialysis vs. peritoneal dialysis: results of a 3-year prospective controlled study.

A prospective comparison of peritoneal dialysis to hemodialysis was undertaken to identify advantages and disadvantages of either treatment relative to the other. Hematologic, biochemical, lipid, and neurobehavioral parameters were followed. Careful controls were imposed to assure that the treatment groups were comparable. Patients on peritoneal dialysis proved to have more normal concentrations of BUN, hemoglobin, potassium, bicarbonate, and high-density lipoproteins. Hemodialysis patients had more normal concentrations of albumin, total protein, and calcium. Hypertriglyceridemia was only minimally greater in peritoneal patients. Neurobehavioral results documented multiple abnormalities in both. The profile of results obtained provides preliminary criteria for selecting either form of dialysis for a particular patient.

Adult↗
PubMed1979

Metabolic studies in familial hypercholesterolemia. Evidence for a gene-dosage effect in vivo.

To investigate the gene-dosage effect in familial hypercholesterolemia (FH), metabolic studies were conducted in a group of well-characterized patients with either heterozygous (n = 7) or homozygous (n = 7) FH and the results were compared to those obtained in normal subjects (n = 6). The turnover of (125)I-labeled low-density lipoprotein (LDL) was measured in all of the normals, all but one of the FH heterozygotes, and in all of the homozygotes. Chemical cholesterol balance was performed simultaneously with the (125)I-LDL turnover in all seven of the homozygotes. With regard to (125)I-LDL turnover, FH homozygotes, who possess two doses of the mutant FH gene, exhibited a threefold increase in the rate of apoLDL synthesis while the fractional catabolic rate (FCR) for the apoprotein was only about one-third of normal. Heterozygotes, who have only one dose of the mutant FH gene, exhibited intermediate values for both parameters; that is, the FCR was two-thirds of normal and the apoLDL synthetic rate was 1.7-fold greater than normal. THE DATA INDICATE THAT THE SINGLE GENE DEFECT IN FH PRODUCES TWO DISTINCT ABNORMALITIES OF LDL METABOLISM: (a) an increase in the synthetic rate for apoLDL and (b) a decrease in the efficiency of apoLDL catabolism. Both defects are more severe in FH homozygotes than in heterozygotes. The FCR for apoLDL in the homozygotes appeared to be fixed at congruent with 17%/d whereas the plasma LDL level varied about twofold. These findings suggest that the twofold variation in plasma LDL levels observed in these seven patients is caused by variation in the plasma apoLDL synthetic rates. Consistent with this conclusion was the finding that the correlation between the plasma LDL level and the apoLDL synthetic rates in the seven FH homozygotes was 0.943. The rate of total body cholesterol synthesis determined by chemical cholesterol balance did not appear to clearly differ between normals and patients with either one or two mutant FH genes. Two of the youngest FH homozygotes exhibited cholesterol overproduction but the other five did not. No consistent abnormality of bile acid metabolism was observed in these patients. Because the daily plasma flux of cholesterol on LDL is about threefold greater than the amount of cholesterol produced per day, a significant amount of the cholesterol liberated from LDL degradation must be reused.

Adolescent↗
PubMed1975

Limitations of the electrocardiographic response to exercise in predicting coronary-artery disease.

The electrocardiographic response to exercise was compared with the results of coronary angiography in 89 patients with Type II hyperlipoproteinemia who had previous myocardial infarction or typical angina or both (43 patients)(Group A), "atypical angina" (16 patients)(Group B)or positive electrocardiographic response to exercise without other evidence of cardiac disease (30 patients)(Group C). Thirty-nine of 43 in Group A had greater than or equal to 50 per cent stenosis, and 26 (67%) of these 39 had negative exercise tests. In Group B, five of the 16 had greater than or equal to 50% stenosis, and three had positive exercise tests (one patient had a false-positive test). In Group C, eleven of 30(37%) had greater than or equal to 50% stenosis; however, nine (30%) had minor stenosis (less than or equal to 50%), and 10(33%) normal coronary arteries. The diagnostic usefulness of exercise electrocardiography is limited. False-negative responses are frequent in patients with clinically suspected coronary disease, and false-positive responses frequent in asymptomatic patients.

Adult↗
PubMedDate not supplied

Primary prevention of coronary disease.

In 1995, the latest year for which statistics are available, heart disease, cancer, and stroke continued to be the three leading causes of death in the United States. Notably, however, a wealth of experience has confirmed that hygienic interventions such as diet, exercise, weight loss, and smoking cessation can reduce the toll from heart disease while also reducing the morbidity and mortality associated with stroke and cancer. This chapter will describe the rationale for the primary prevention of coronary heart disease (CHD), review the basic concepts involved in cholesterol screening, and update the reader regarding key preventive measures, such as diet, exercise, and smoking cessation. Also highlighted will be recent clinical trial results suggesting the benefits of lipid-lowering drugs in "high-risk" individuals who have not experienced a coronary event. These findings represent an exciting advance that emphasizes the value of preventive efforts in curbing CHD.

Cholesterol↗
PubMedDate not supplied

Standard parameters of diabetic control: are they reliable?

To evaluate the reliability of the tradional methods to assess short-term control of diabetes, 25 children with insulin-dependent diabetes were studied with a 24-h glucose profile in addition to the traditional assessment techniques. Patient compliance was elminated as much as possible from the experimental design. The correlation of the routine methods with the 24-h glucose profile was excellent, and a scoring system for control was empirically derived. The single method of assessment that correlated best with the overall control score was the traditional daily urine test. In 6 of the 25 subjects studied, relative hypoglycemia was observed, occurring asymptomatically at night, and was followed by a hyperglycemic rebound. Traditional assessment techniques did not detect this event. Five additional patients had symptomatic daytime hypoglycemia. We conclude that the traditional daily urine tests are adquate indicators of day-to-day control in most diabetic patients, given adquate compliance. Our data also suggest that asymptomatic nocturnal hypoglycemia occurs frequently in children with diabetes, although clinical proof is difficult in the absence of a 24-h glucose profile.

Adolescent↗