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Biomedical subjects

D Ney

Publications and source records attributed to D Ney.

17 recordsLinked to original sources

Dietary management of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD). A case report and survey.

Current dietary management of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD; long-chain-(S)-3-hydroxyacyl-CoA:NAD+ oxido-reductase, EC 1.1.1.211) deficiency (LCHADD) is based on avoiding fasting, and minimizing energy production from long-chain fatty acids. We report the effects of various dietary manipulations on plasma and urinary laboratory values in a child with LCHADD. In our patient, a diet restricted to 9% of total energy from long-chain fatty acids and administration of 1.5 g medium-chain triglyceride oil per kg body weight normalized plasma acylcarnitine and lactate levels, but dicarboxylic acid excretion remained approximately ten times normal. Plasma docosahexaenoic acid (DHA, 22:6n-3) was consistently low over a 2-year period; DHA deficiency may be related to the development of pigmentary retinopathy seen in this patient population. We also conducted a survey of metabolic physicians who treat children with LCHADD to determine current dietary interventions employed and the effects of these interventions on symptoms of this disease. Survey results indicate that a diet low in long-chain fatty acids, supplemented with medium-chain triclyceride oil, decreased the incidence of hypoketotic hypoglycaemia, and improved hypotonia, hepatomegaly, cardiomyopathy, and lactic acidosis. However, dietary treatment did not appear to effect peripheral neuropathy, pigmentary retinopathy or myoglobinuria.

3-Hydroxyacyl CoA Dehydrogenases↗

The effect of self-monitoring the INR on quality of anticoagulation and quality of life.

In a prospective cohort study the influence of self-monitoring of the International Normalized Ratio (INR) was examined on 100 consecutive patients for a period of 6 months. Quality of life changed in a positive way. Independence and better organization of vacation and spare time were the most frequently mentioned advantages of the new method. Quality of anticoagulation by using a self-monitoring device was improved compared to the values before using the self-monitoring device. For measuring the INR, the usage of a portable monitor as the primary method can be recommended in selected patients receiving oral long-term anticoagulation.

Anticoagulants↗

[MRI and CT of parotid diseases in HIV-positive patients].

We report five cases of HIV patients with parotid pathology during a period of one year. All patients (4 men and 1 woman between the ages of 32 and 47 years) had a MRI or a CT confirmation of the parotid gland lesion. Three patients exhibited parotid gland cysts, one a nonspecific chronic inflammation and one an enlargement of the parotid gland with some benign lymphoepithelial lesions. Two patients underwent ultrasound-guided fine-needle aspiration biopsy. The cytology examination confirmed the benignity of the lesions. Finally, we expose the clinical management of parotid enlargements in HIV-positive patients.

Adult↗

Three-dimensional imaging of the lung in vivo: work in progress.

It has previously been demonstrated that three-dimensional (3D) displays of the lung and bronchial tree can be generated from computed tomography (CT) scans of lung specimens. Subsequent refinement of the reconstruction algorithms has allowed high-resolution reconstructions of lungs in vivo. With the introduction of low-dose CT scan protocols, use of the technique may become more common in the radiologic community. The many potential clinical applications for 3D imaging of the lung include an aid to bronchoscopy and improved surgical planning. We present the technical details for 3D imaging of the lungs in vivo as well as three representative case studies.

Adult↗

Interactive multidimensional display of magnetic resonance imaging data.

Acquisition of multiparametric images in multiple planes often requires unacceptably long scanning times. The ability to display high quality planar cuts in arbitrary planes from single plane (eg, transaxial, coronal, or sagittal plane) images would alleviate the need to acquire images in multiple planes. The need to display data from three-dimensional volume acquisitions also poses a problem to the radiologist. We have developed an interactive multidimensional display tool for magnetic resonance data. The tool presents three orthogonal planes (such as transaxial, coronal, and sagittal) simultaneously and allows the user to interactively roam through the data set. The user can select any arbitrary oblique plane and obtain the corresponding reformations. Additionally the tool allows the correlated display of sets of differently acquired data. This tool offers an effective means for the display of isotropic data and reformated planar data. The ability to interact directly with the data allows increased transference of information to the radiologist and referring physician.

Brain↗

Similar effects of zinc deficiency and restricted feeding on plasma lipids and lipoproteins in rats.

The objective of this study was to determine whether alterations in HDL composition observed previously were due specifically to zinc deficiency or to reduction in food intake. Rats were placed into three groups and fed for 21 d a zinc-adequate diet (100 ppm) ad libitum, or a zinc-deficient diet (less than 1 ppm) ad libitum, or the zinc-adequate diet at an intake equal to that of the deficient group. Blood plasma was fractionated into VLDL, LDL and HDL fractions, and plasma and the isolated fractions were analyzed for lipids and apolipoprotein composition. Analysis of plasma and liver zinc indicated that animals consuming the low zinc diet were deficient. Zinc deficiency and restricted feeding were associated with lower plasma and VLDL triglyceride levels and lower HDL cholesterol levels. The similarities in overall pattern of lipoprotein composition between the zinc-deficient and restricted-intake groups indicate that reduction in food intake may account for the differences in lipoprotein composition which were observed.

Animals↗

An evaluation of protein requirements in methylmalonic acidaemia.

A 3-month-old girl and a 13-month-old boy with vitamin B12-unresponsive methylmalonic acidaemia were studied to determine responses to varying levels of protein intake of growth, nitrogen balance and organic acid metabolism. A linear increase in the excretion of methylmalonic acid was observed in both patients above a critical level of protein intake. The inflection point was judged to reflect a ceiling above which amino acid intake exceeded requirements and catabolism was initiated. Below this point in each infant there was a plateau of minimal excretion of methylmalonic acid. Within this plateau level a reasonable rate of growth and metabolic stability were achieved at intakes between 0.70 and 0.75 and between 0.75 and 1.17 g protein kg-1, respectively, indicating that there is a range of protein tolerance and the importance of an individual approach to the provision of protein in patients with methylmalonic acidaemia. In the 3-month-old infant, nitrogen equilibrium was achieved at protein intakes above 0.6 g kg-1 and modest nitrogen retention was attained at a protein intake of 0.75 g kg-1, a level at which the excretion of methylmalonic acid was minimal and weight gain satisfactory. A protein intake of 1.25 g kg-1 was required to achieve a level of nitrogen retention often considered optimal for normal growth; however, this infant demonstrated an elevated excretion of methylmalonic acid and was close to clinical illness at this level of protein intake. The 13-month-old infant demonstrated a normal level of nitrogen retention, minimal excretion of methylmalonic acid, and a satisfactory rate of growth at protein intakes of 1.0-1.17 g kg-1. The values should prove useful guidelines for the management of infants requiring minimal intakes of protein. In studies carried out at 18-20 months of age, supplementation of the basic diet containing 0.75 g kg protein-1 with a mixture of amino acids not containing the precursors of methylmalonic acid was associated with increase of retention of nitrogen and increased concentrations of some essential amino acids in plasma, but effects on growth and the excretion of methylmalonic acid were not significant.

Amino Acid Metabolism, Inborn Errors↗

Studies on requirements for amino acids in infants with disorders of amino acid metabolism. I. Effect of alanine.

Two infants with disorders of propionate metabolism were studied at 7 months of age to determine optimum levels of intake of protein and calories to meet the requirements for essential amino acid for growth in infancy, and at the same time minimize the accumulation of toxic intermediates. An effect of alanine was found that permitted growth at otherwise limiting levels of protein intake. This was not simply an effect of nonessential nitrogen as neither glycine nor glutamic acid could substitute for alanine in this protein-sparing effect. This appears to represent further evidence of the relationship between alanine and the branched-chain amino acids and of the importance of the alanine-glucose cycle in human physiology.

Alanine↗

Metabolic and therapeutic assessment of gestational diabetes by two-hour and twenty-four-hour isocaloric meal tolerance tests.

Lean and obese women with gestational diabetes (GDM) were given two different isocaloric meal challenge tests to assess glucose and insulin responses. Forty-three pregnant women received a 400-kcal isocaloric breakfast meal tolerance test (mini-MTT). Twenty of the subjects were also given a 2000-kcal isocaloric diet with three meals and three snacks during a 24-h period (maxi-MTT). This was the first study to utilize the physiologic challenge of mixed meals to compare insulin and glucose responses of both obese and lean normal pregnant women and women with GDM around the clock. Normal obese pregnant women had higher integrated glucose and insulin values around the 24-h clock (P less than 0.003 and less than 0.03, respectively) than lean pregnant women. Lean and obese women with GDM also responded differently to the physiologic challenge of mixed meals. Some, but not all, obese diabetic subjects were markedly hyperinsulinemic in contrast to lean diabetic women who were relatively insulin deficient. One normoglycemic massively obese 18-yr-old pregnant woman was unexpectedly found to be severely hyperinsulinemic. The two meal tolerance tests clearly defined a delay in the release of insulin in women with GDM (lean and obese) and markedly different quantitative insulin responses to identical meal challenges in obese diabetic subjects. Maternal hyperinsulinemia was positively correlated with prepregnancy body mass index (kg/m2) and heavier infants, but not with plasma glucose levels. These studies provide evidence that GDM is a heterogeneous syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Dietary management of oculocutaneous tyrosinemia in an 11-year-old child.

An 11-year-old girl with keratitis and plantar keratosis had tyrosinemia. The concentration of tyrosine in the plasma was 16.5 mg/dL. Dietary intake of phenylalanine and tyrosine was systematically varied, and the plasma concentrations of tyrosine and nitrogen balance were studied. It was necessary to achieve a total intake of phenylalanine and tyrosine less than 100 mg/kg/day to obtain plasma concentrations of tyrosine of less than 10 mg/dL. After dietary therapy was started, the keratitis resolved promptly, and the patient remained asymptomatic during a period of 16 months in which the mean plasma concentration of tyrosine was 11.1 mg/dL. The dietary management of a child at this age presents a different problem from that of a young infant. It can be successfully pursued at home, as well as in the carefully regulated environment of a clinical research center.

Adolescent↗

A tool for assessing compliance with a diet for diabetes.

In summary, criteria to define good, acceptable, and unacceptable compliance with a CONTROL or HCF diabetic diet were established. With the use of these criteria, a simplified system for the evaluation of compliance was developed. The compliance system used an interview approach and a checklist on which patients recorded their food intake in terms of the number of food exchanges consumed throughout the day. The results of this study suggest that (a) research subjects will keep accurate food records using a checklist system for up to 30 weeks; (b) the described compliance system is a valuable educational tool and can assist in the interpretation of clinical data used in diabetes management; and (c) the assigned compliance grades correlate with quantitative parameters of diabetic control.

Adult↗

Vitamin A deficiency and the metabolism of glycosaminoglycans and ascorbic acid in the rat.

Weanling rats were fed diets with and without the addition of retinyl palmitate at 6,500 units/kg. The supplemented groups were fed either ad libitum or food was restricted daily to that amount consumed by the group of rats receiving the unsupplemented diet. After a 10 week experimental period, signs of vitamin A deficiency were observed (growth plateau, xerophthalmia) and liver values as retinol were only 1% of control values. Relative to the two control groups, vitamin A deficiency resulted in approximately 30% lower liver, 50% lower blood and 40% lower urinary ascorbic acid. Vitamin A deficiency did not appear to result in significant and direct impairment of GAG sulfate metabolism. Although the total amount of GAG in rat skin was increased, the composition of GAG fractions did not appear to be altered by vitamin A deficiency. Studies regarding the incorporation and disappearance of 35S-sulfate in vivo into GAG fractions obtained from skin indicated no serious impairment in GAG turnover with vitamin A deficiency. Twenty-four hour urine samples were also collected for estimation of 35SO4 excreted in GAG and non-GAG fractions. Likewise, little change was observed with respect to radioactivity associated with sulfate fractions excreted in urine. Although many previous studies have directly linked vitamin A with sulfation of GAG, the results reported here suggest that if there is an alteration in GAG sulfate metabolism, it is probably an indirect consequence of vitamin A status.

Animals↗

Nutritional management of pregnancy complicated by diabetes: historical perspective.

The important role of diet in the management of pregnancies complicated by diabetes has been recognized since the nineteenth century. In this historical review we have traced the evolution of the diabetic diet from the pre-insulin era, when diabetic pregnancies were not only rare, but accompanied by high maternal mortality and fetal loss to 1981, when the nutritional management of carbohydrate intolerance during gestation is again raising provocative questions. Our recent understanding of diabetes as a heterogeneous syndrome, the 1979 dietary guidelines of the American Diabetes Association (ADA), and the 1980 revised Recommended Dietary Allowances (RDA) for pregnant and lactating women are summarized as representative of the current approach to the nutritional management of diabetic pregnancies. Many questions remain unanswered. These include the hundred-year-old debate concerning the optimal amount of carbohydrate in the diabetic diet, the possible beneficial role of large amounts of dietary fiber, and the nagging concern about total caloric intake in type I insulin-dependent diabetes mellitus (IDDM) versus type II non-insulin-dependent diabetes mellitus (NIDDM) pregnant diabetic women. We suggest that nutritional counseling during gestation in the future may need to be more highly individualized as metabolic distinctions between different types of patients with carbohydrate intolerance are more clearly delineated.

Adult↗

Decreased insulin requirement and improved control of diabetes in pregnant women given a high-carbohydrate, high-fiber, low-fat diet.

Five quantitative measures of diabetic control [HbA1c determinations, mean 24-h plasma glucose values, mean amplitude of glycemic excursions (MAGE), mean 24-h urinary loss of glucose, and daily exogenous insulin requirement] were compared in 20 pregnant women who were randomly assigned to either a high-carbohydrate, high-fiber diet (HCF) that was low in fat or to a control diet commonly prescribed for pregnancy. Eleven women followed the HCF diet and nine subjects, the control diet, from baseline entry into the study until delivery. Dietary compliance was excellent, with 78% of the women in each group rated good or acceptable. HbA1c values were similar in both groups at baseline (HCF: 11.0 +/- 0.5% versus control: 10.2 +/- 0.6%), with no different predelivery values (8.6 +/- 0.4%). Mean 24-h plasma glucose levels improved in patients on both diets, with lower values noted in the HCF group at predelivery. MAGE values and standard deviations did not differ significantly in the two groups. Glycosuria decreased markedly in both dietary groups, but differences between groups were not significant. Improved control of diabetes on the HCF diet was achieved with significantly lower increments in insulin dose during gestation (HCF baseline: 32 +/- 8 U/24 h to 66 +/- 10 U/24 h versus control baseline: 27 +/- 9 U/24 h to 108 +/- 12 U/24 h, P less than 0.03). Outcome of pregnancy did not differ in the two groups of patients, but women on the HCF diet gained less weight than those on the control diet (26 +/- 3 lb versus 35 +/- 5 lb, P less than 0.05). Mean newborn gestational age was similar in the two groups (HCF: 37.2 +/- 0.7 wk versus control: 36.5 +/- 0.7 wk). Mean birth weight in infants of HCF mothers was 3809 +/- 248 g versus 3313 +/- 278 g in infants of control mothers (P less than 0.05). We conclude that although marked improvement of diabetic control occurred on both regimens, patients on the HCF diet achieved better control of diabetes with significantly lower increments in exogenous insulin.

Adult↗