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Biomedical subjects

C Legum

Publications and source records attributed to C Legum.

64 records · Page 4Linked to original sources

Ultrastructure of cultured fibroblasts in mucolipidosis type IV.

Five patients have been classified as suffering from mucolipidosis type IV on the basis of the findings in various tissues and in cultured fibroblasts. The light and electron microscopic features of cultured fibroblasts in this disease are described in detail. The differentiation of this condition from other lysosomal storage diseases and other types of mucolipidoses is discussed. The importance of identifying this disease for purposes of intrauterine diagnosis and eventual understanding of the underlying enzyme defect is stressed.

Cell Membrane↗

Acute neonatal isovaleric acidemia. A report of two cases.

Two fatal cases of the fulminant type of isovaleric acidemia are described. Attention is drawn to the existence of two forms of the disease, the severe "Newman" type, occurring in the first week of life and the milder "Tanaka" type, with a later onset. The importance of ruling out isovaleric acidemia in any newborn infant with acidosis is emphasized.

Adult↗

Sucrase and cellular development.

The cellular changes that take place as the intestinal cell migrates from crypt to villus are morphologically and biochemically remarkable. It is fortunate that many of these phenomena can be delineated by following enzymic activities. Sucrase-isomaltase is a particularly fascinating enzyme complex because it is a marker of the differentiated cell. Sucrase is inducible with steroids and protected by the substrate sucrose. Purified enzyme can be used to stimulate production of specific antibodies in goats; these antibodies have been used as probes to locate enzymically active and inactive antigen in the cells of the crypt and villus respectively. Further examination of the enzyme has indicated a molecular weight of 200 000--350 000. These higher molecular weight components are located in the brush border of the enterocytes. Lower molecular weight subunits are antigenically active and are in the cytosol. It is assumed that these smaller components are enzymically inactive pre-combination subunits of the sucrase-isomaltase complex and that the sucrase-isomaltase of the brush border is an aggregate of these subunits. The California sea lion, which is deficient in intestinal sucrase activity, does have isomaltase activity. This finding supports the concept that there are different gene complexes for sucrase and for isomaltase.

Aging↗

Doppler velocimetry of the umbilical artery as a predictor of pregnancy outcome in pregnancies characterized by elevated maternal serum alpha-fetoprotein and normal amniotic fluid alpha-fetoprotein.

OBJECTIVE: Women with elevated maternal serum alpha-fetoprotein (MSAFP) and normal amniotic fluid alpha-fetoprotein (AFAFP) are at an increased risk of an adverse pregnancy outcome. Such MSAFP elevations are probably the consequence of transplacental leakage caused by placental abnormalities. These may result in disturbed bloodflow through placental vessels. The purpose of this study was to assess whether measurement of such disturbances by Doppler velocimetry of the umbilical artery has a predictive value for pregnancy outcome. STUDY DESIGN: The study group consisted of 85 patients, in whom the only finding was elevated maternal serum alpha-fetoprotein. Systolic/diastolic (S/D) ratios were calculated using a continuous wave Doppler measurement of the umbilical artery, performed at 6 to 8-week intervals. Serial results for each individual were incorporated into a single 'Velocimetry Score'. RESULTS: In group B (14 patients) with an abnormally elevated umbilical S/D ratio, a higher incidence of intrauterine growth retardation (42.9%), preterm deliveries (78.6%), and fetal loss (42.9%) was noted, as compared with group A (71 patients) with a normal S/D ratio. CONCLUSIONS: Umbilical artery Doppler velocimetry may serve as a predictor of pregnancy outcome in the high-risk group characterized by elevated MSAFP.

Adult↗

Doppler velocimetry of the umbilical artery as a predictor of outcome in pregnancies characterized by elevated beta-subunit human chorionic gonadotropin.

OBJECTIVE: Women with unexplained elevated maternal serum beta-subunit human chorionic gonadotropin (beta-HCG) are at an increased risk for adverse pregnancy outcome, most likely due to placental abnormalities. Such abnormalities may also result in disturbed blood flow through placental vessels. The purpose of this study was to assess whether Doppler velocimetry of the umbilical artery has a predictive value for pregnancy outcome in patients with unexplained elevated maternal serum beta-HCG. STUDY DESIGN: The study group included 63 patients, in whom the only finding was elevated maternal serum beta-HCG. Systolic/diastolic (S/D) ratios were calculated using a continuous wave Doppler measurement of the umbilical artery, performed beginning at 22 weeks of gestation and followed at 6- to 8-week intervals. Serial results for each individual were incorporated into a single 'velocimetry score', calculated as the rate of abnormal velocimetry measurements. RESULTS: beta-HCG was found to be associated with poor pregnancy outcome: including intrauterine growth restriction (IUGR) (19%), pregnancy-induced hypertension (PIH) (14%), and preterm labor (PTL) (19%). Patients were then divided into 2 groups according to their velocimetry score: group A, VS < or = 80 (n = 47), and group B, VS > 80 (n = 16). A low velocimetry score was associated with a higher rate of IUGR, PIH, and a significantly higher rate of PTL. CONCLUSIONS: Umbilical artery Doppler velocimetry may serve as a predictor of pregnancy outcome in the high-risk group characterized by unexplained elevated beta-HCG.

Biomarkers↗

Early pregnancy screening for neural tube defects in Israel.

A pilot project to detect neural tube defects (NTD) of the fetus by maternal serum alpha-fetoprotein (MSAFP) screening of women in early pregnancy was initiated in Tel Aviv in 1982 at the instigation of the Israel Ministry of Health. The program was designed to be an extension of routine pregnancy care, which in this city is provided in municipal family clinics that are attended by about 50% of pregnant women before the 20th week of pregnancy. Of these women, 89% complied with the program. Women with a MSAFP level above a cutoff point of 2.4 multiples of the median (MOM) were invited for an ultrasound examination of the fetus, without having to repeat the MSAFP test, thereby reducing maternal anxiety. This deviation from the usual test system protocol did not impair sensitivity (87%), or specificity of the test on its own (95.6%), or in combination with ultrasound examination of the fetus and alpha-fetoprotein and acetylcholinesterase testing of the amniotic fluid (99.9%). The program detected 13 fetuses with an NTD; there were two false-negative results and one false-positive. The predictive value of a positive test was 93%. Its effectiveness as a preventive measure was impaired by the fact that 50% of pregnant women did not attend the family clinic before the 20th gestational week. An educational program for professionals and for the public is contemplated in order to reduce this proportion. Only 50% of normal twin pregnancies had an elevated MSAFP. A check on compliance with other screening systems during the interview for MSAFP screening led to the detection and elective abortion of two fetuses with Tay-Sachs disease. MSAFP screening in Israel is cost-effective rather than cost-beneficial.

Amniocentesis↗

Improved reliability of a serum alpha-fetoprotein enzyme immunoassay compared with a radioimmunoassay.

During the 6-month period between September 1982 and February 1983, serum samples were obtained from 850 pregnant women attending the municipal family clinics in Tel Aviv. All serum samples were tested by alpha-fetoprotein (AFP) enzyme immunoassay (EIA), and 650 samples were also tested by AFP radioimmunoassay (RIA). Comparisons were made between the absolute values, the medians, and the multiples of the median (MOM) obtained by each method. The ratios of the 90th percentile to the median and of the median to the 10th percentile were also compared. Inter- and intraassay variation were determined for both methods. Correlating the test results with the birth results showed that both methods detected the four fetuses with a neural tube defect (NTD) and three of nine twin pairs, when using a cutoff point of greater than or equal to 2.5 MOM. Elevated maternal serum AFP (MSAFP) levels were also noted in 32 normal singletons (3.8%). There were no false negative results during this phase of the study. Although the median values were similar for both methods, the mean of the ratios of the median to the 10th percentile and the 90th percentile to the median, showed a reduced spread for the EIA method.

Evaluation Studies as Topic↗