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Biomedical subjects

E W Naylor

Publications and source records attributed to E W Naylor.

At least 55 records · Page 3Linked to original sources
PubMed1981

Urinary pyrimidine excretion in arginase deficiency.

A high-performance liquid-chromatographic method was used to separate and identify uracil, uridine, pseudouridine and orotic acid after preliminary extraction in two patients (McKusick 20780). Urinary uracil excretion was 10-35 times normal in both patients with arginase deficiency. Uridine and orotic acid, not normally detected, were excreted in large amounts and were directly influenced by protein intake. Their excretions were correlated with urinary arginine excretion. Urinary uracil levels remained consistently high and showed minimal variations with increased protein intake or urinary arginine levels. The measurement of urinary pyrimidines appears to be useful for the detection, differential diagnosis and dietary monitoring of patients with urea cycle disorders. The data presented extends this observation to include patients with arginase deficiency.

Adolescent↗
PubMed1981

Adrenal adenomas in a patient with Gardner's syndrome.

Gardner's syndrome is an autosomal dominant condition characterized by multiple colorectal polyposis, associated with various soft- and hard-tissue tumors. The occurrence of adrenal adenomas in patients with the syndrome has not been fully appreciated. The following is a report of a member of the original Utah kindred #109, first described in the early 1950's who was found at autopsy to have bilateral adrenal adenomas. A review of the literature resulted in the identification of six cases with adrenal adenomas and one with a primary adrenal carcinoma. The association with the syndrome of these adrenal tumors, as well as other endocrine tumors, especially thyroid tumors, is discussed.

Adenoma↗
PubMed1980

Enzymatic studies of urinary isomeric chondroitin sulfates from patients with mucopolysaccharidoses. The application of high performance liquid chromatography.

The high-performance liquid chromatographic (HPLC) method for the determination of unsaturated sulfated disaccharides is a comprehensive and reliable method which expedites ensymatic studies of isomeric chondroitin sulfates. Responses for these unsaturated disaccharides derived from urinary chondroitin sulfates were linear from 100 ng to 10 micrograms injected and good quantitation was obtained for 25 microliters or less of samples placed on the column. This method which is more sensitive and accurate than methods now being used has considerable potential for the chemical diagnosis of patients with mucopolysaccharidoses and for the clarification of glycosaminoglycan structure. The isomeric chondroitin sulfates in urines from patients with mucopolysaccharidoses were studied by enzyme digestion with chondroitinases followed by HPLC determination of the sulfated unsaturated disaccharides produced. Evaluation by HPLC of the unsaturated 4-sulfated disaccharide produced by digestion of the urinary GAG with chondroitinases ABC and AC revealed rapidly and quantitatively the large amounts of dermatan sulfate present in Hurler, Hunter, and Maroteaux-Lamy urines. Chondroitin 4-sulfate predominated in Sanfilippo urinary isomeric chondroitin sulfates whereas chondroitin 6-sulfate and chondroitin 4-sulfate were shown to be present in nearly equal amounts in Morquio urine. An oversulfated chondroitin sulfate was detected in small amounts in some of these urines. This was demonstrated by the detection of an unsaturated disulfated disaccharide after digestion with chondroitinase ABC but not with chondroitinase AC.

Chondroitin↗
PubMed1980

Gardner's syndrome. Recent developments in research and management.

In recent years, a number of comprehensive reviews have been written on inherited intestinal polyposis syndromes (1-7), but none has dealt specifically with Gardner's syndrome and none has focused on basic research being carried out in an attempt to understand this syndrome and to improve the medical management of affected patients. A better understanding of this rare genetic disorder is essential for surgeons, gastroenterologists, cancer researchers, and geneticists alike. To the clinician, it poses difficult challenges in management; to the cancer researcher, it presents a rare opportunity to study very early premalignant transformations; and to the geneticist, it poses exciting questions at the cellular, chromosomal, and molecular levels.

Adult↗
PubMed1980

Urine screening for metabolic disease in newborn infants.

A new method for urine screening for metabolic disease in newborn infants is described. A battery of bacterial inhibition assays to test urine-impregnated filter paper from 3- to 4-week-old infants for amino acids, purines, and pyrimidines was used. We were able to establish the accuracy and efficiency of the method by examining 289 unknown specimens from other laboratories and by collecting and testing 18,400 newborn infants' urine specimens. The major advantages over existing chromatography methods are that: (1) the technology to perform the test already exists in most laboratories screening for metabolic disorders; (2) it is relatively inexpensive; (3) collection of the sample is easy and cooperation of the parents is good; (4) the false positive rate is low (0.9%); and (5) tests can be targeted to detect clinically significant disorders. In this screening program, we detected two cases of persistent neonatal tyrosinemia, two cases of cystinuria, and one case of citrullinemia. These results suggest that urine screening is a good adjunct to blood screening of newborn infants.

Humans↗
PubMed1980

Fluorometric micromethod for determination of arginase activity in dried blood spots on filter paper.

We describe a microfluorometric method for determination of arginase activity in dried blood spots on filter paper. The arginase in discs punched from such dried blood specimens is activated by preincubation with Mn2+ at 37 degrees C. After incubation with substrate at the same temperature, urea is determined fluorometrically by oxidation of NADH to NAD+ in a coupled kinetic reaction. We compare the results of this method with those of a colorimetric method involving liquid blood samples, and assess the stability of the enzyme in dried blood on filter paper. The presence of serum has no effect on the activity. This method may be useful in the early detection of arginase deficiency and certain hematological disorders.

Adult↗
PubMed1979

Measurement of urinary pyrimidine bases and nucleosides by high-performance liquid chromatography.

A rapid procedure for the isolation, separation, identification and measurement of urinary pyrimidine bases and nucleosides by high-performance liquid chromatography (HPLC) is presented. The initial isolation of these compounds from urine was accomplished with small disposable ion-exchange columns. HPLC was performed on a silica gel column with a mobile phase composed of methylene chloride, methanol and 1 M aqueous ammonium formate buffer. Peaks were recorded at both 254 nm and 280 nm and the response ratio was used in combination with the elution volume for compound identification. The minimum detectable amount (signal-to-noise ratio = 2) ranged from 0.2 ng for uracil to 2.2 ng for cytidine. Linearity and recovery for thymine, uracil, uridine, pseudouridine, orotic acid and orotidine added to urine was demonstrated over almost a 10(3) concentration range. The potential application of this method for the study of inborn errors in the urea cycle is discussed.

Chromatography, High Pressure Liquid↗
PubMed1979

Desmoid tumors and mesenteric fibromatosis in Gardner's syndrome: report of kindred 109.

Kindred 109, from which Gardner's syndrome was first described, now has 224 members, 28 of whom have inherited the syndrome. Among the group of 28, desmoid tumors or mesenteric fibromatosis or both have developed in eight (29%). In four patients, the fibrous dysplasia appeared to originate in postsurgical abdominal incisional scars; in two of these cases, the mesenteric involvement resulted in death. In one patient, the process was present in the mesentery at the original operation. In three patients, the fibrous dysplastic lesions were extraincisional, with no known trauma associated with their occurrence.

Abdominal Muscles↗
PubMed1979

Early detection of adenomatous polyposis coli in Gardner's syndrome.

Gardner's syndrome, an autosomal dominant disorder, consists of multiple polyposis of the colon associated with various soft- and hard-tissue tumors. The appearance of adenomatous hyperplasia and polyposis in at-risk patients before adolescence has not been full appreciated. Four preadolescent children from a kindred with Gardner's syndrome were examined by use of colonoscopy and mucosal biopsy. In three children (18 months, 6 years, and 9 years old) adenomatous hyperplasia or polyposis was found. The colon of the fourth child (3 years old) was normal. The three affected children were asymptomatic. The youngest had a barium enema and results were normal. The oldest child had polyps. Biopsies revealed focal atypical hyperplasia of the glands with pseudostratification of the epithelial cells, frequent mitotic figures, and the absence of goblet cells. More severe manifestations were noted in the splenic flexure than in the sigmoid flexure or rectum. The youngest patient showed early adenomatous hyperplasia characterized by a marked reduction of the goblet cells, especially in the surface epithelium. Colonoscopy and mucosal biopsies are mandatory in at-risk children. By deferring colonic examination until adolescence, a patient is placed at risk for malignant degeneration of the adenomatous tumor.

Adenoma↗
PubMed1978

Erythropoietic protoporphyria, heterozygous cystinuria, and reduced peptidase A activity in a patient with 46,XX/46,XX,18q--mosaicism.

An interesting patient with a deletion of the long arm of chromosome 18 is presented. Her symptoms are severe in comparison with some other 18q--patients, yet she was found to have a mosaicism with a normal 46,XX karyotype in about 20% of her cultured lymphocytes. In addition, she had erythropoietic protoporphyria, was heterozygous for type II or III cystinuria, and had reduced levels of peptidase A activity. Detailed studied on the patient, her family, and two additional 18q--patients suggest that the association with erythropoietic protoporphyria is coincidental and that the cystinuria gene was inherited from the patient's father. The reduced peptidase A activity, however, supports earlier observations that the peptidase A locus maps in the q22 to terminus region of chromosome 18.

Child↗
PubMed1978

Newborn screening for maple syrup urine disease (branched-chain ketoaciduria).

Routine newborn screening for maple syrup urine disease (MSUD) has been conducted since 1964, and more than 9 1/2 million newborns throughout the world have been tested with use of a bacterial inhibition assay (BIA) for leucine on dried filter paper blood specimens. Forty-three confirmed cases of the "classical" and the "intermediate" variant forms have been detected. The frequency of MSUD, based on these data, is approximately one in 224,000 newborns. The sensitivity and the specificity of the leucine BIA are demonstrated. There are several problems in routine screening for MSUD, including the fact that the "intermittent" variant form will be missed. A brief summary of the clinical course of the 13 cases detected by our collaborative laboratories is presented.

Bacillus subtilis↗
PubMed1978

Micromethod for estimating adenosine deaminase activity in dried blood spots on filter paper.

We describe a fluorometric micromethod for measuring adenosine deaminase activity in dried blood spots on filter paper. Earlier methods require venipuncture and preparation of washed erythrocytes; in the present method, whole capillary blood, spotted on filter paper and mailed (dried) to a central laboratory, is used. The stability of the enzyme in dried blood on filter paper was assessed. The results were compared with those of a spectrophotometric method. The presence of serum appears not to affect the estimation of the activity and the method may be useful in early detection of severe combined immunodeficiency disease and hereditary hemolytic anemia.

Adenosine Deaminase↗
PubMed1977

Penetrance and expressivity of the gene responsible for the Gardner syndrome.

The Gardner syndrome is an autosomal dominant condition characterized by multiple polyposis of the colon, associated with various soft- and hard-tissue tumors. Our original kindred, first reported in the early 1950's has been updated and serves as the basis for a discussion of the penetrance and expressivity of the gene responsible for the syndrome. The family consists of 188 members spread over six generations, with 28 individuals clearly documented as having the syndrome. Using two different methods of calculating penetrance, the responsible gene was found to be fully penetrant. This observation was confirmed by an analysis of 160 additional sibships from the literature. This estimation of penetrance is considerably higher than has been previously reported. The expressivity of the gene, however, is quite variable, and this is illustrated using examples from both our kindred and the literature.

Colonic Neoplasms↗