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D A Luthy

Publications and source records attributed to D A Luthy.

67 records · Page 4Linked to original sources
PubMed1984

Cesarean birth and neonatal mortality in very low birth weight infants.

The authors attempted to relate neonatal mortality to method of delivery in a series of 345 infants, weighing 700 to 1500 g, who were born in King County, Washington, from 1977 to 1979. Overall, 38% of infants delivered vaginally died as opposed to 32% of those with cesarean births. However, after adjustment for birth weight, presentation, and place of delivery, cesarean birth was not associated with reduction in mortality. Even among those infants with a breech presentation, a group believed (on the basis of previous studies) to particularly benefit from cesarean birth, the data failed to show any mortality reduction. Based on the results of this study of very low birth weight singleton infants, it appears that the reduced neonatal mortality associated with cesarean birth, if present at all, is small in magnitude.

Birth Weight↗
PubMed1983

Rh isoimmunization related to amniocentesis.

We report on the incidence of Rh isoimmunization after genetic amniocentesis at our institution. In 115 Rh negative women who underwent amniocentesis and subsequently delivered Rh positive infants, there were 4 (3.4%) sensitizations before birth. This was significantly greater than the 1.5% rate of gestational sensitization found in pooled populations of women who did not undergo amniocentesis. We also noted a significant increase in the number of sensitizations that occurred before 28 weeks. The results were consistent with those of previous studies of this issue, and are discussed in relation to current policies for managing Rh negative women who have second trimester amniocentesis.

Adult↗
PubMed1981

Prenatal diagnosis of neural tube defects: predictive value of AF-AFP in a low-risk population.

Amniotic fluid alpha-fetoprotein (AF-AFP) determinations were performed on 1,215 women who were at low risk for fetal neural tube defects and who were undergoing mid-trimester amniocentesis for cytogenetic indications, primarily age-related aneuploidy. Maternal sera obtained before amniocentesis and amniotic fluids were assayed in duplicate for alpha-fetoprotein by radioimmunoassay. Of the 1,215 low-risk women, eight (0.7%) had significant elevations of AF-AFP (greater than or equal to +5 SD). In none of the cases was the elevation associated with a fetal neural tube defect. Two cases with elevated AF-AFP were associated with chromosome aberrations; one with impending fetal demise; one with fetal blood contamination; and one case was due to a laboratory error. In one case, no source for the elevated AFP was found, and a normal infant was delivered at term. In the final two cases, the cause of the elevated AF-AFP was a fetal abdominal wall defect (one gastroschisis and one omphalocele). The predictive value of an elevated AFP varies with the population screened, and is reduced by routine ultrasonography before amniocentesis, which at least identifies anencephaly. In a low-risk population, an elevated AF-AFP is most often not associated with a fetal neural tube defect. Because of the low predictive value and the nonspecificity of AF-AFP, genetic counselors should reconsider the recommendation of routine AF-AFP in low-risk maternal populations.

Amniocentesis↗
PubMed1980

Prenatal genetic diagnosis and elective abortion in women over 35: utilization and relative impact on the birth prevalence of Down syndrome in Washington State.

We have examined the relative contributions of a population-based antenatal detection program and unrestricted elective abortion used by women 35 years old and over in Washington State and King County for 1976--1977 to the declining birth prevalence of Down syndrome (DS). The amniocentesis/live birth (LB) ratio for women 35 years old and over was 20.5/100 LBs for King County and 11.7/100 LBs for Washington State in 1977. For the state in 1976, abortion ratios/1,000 LBs were 571 for women 35 to 39 years old and 1,096 for women 40 years old and over. Based on the total Washington State data, elective abortion has a greater impact on averting DS births than does the antenatal detection program. The impact of elective abortion appears to be related to its disproportionate use by women 35 years old and over compared to their contribution to the population of of LBs.

Abortion, Legal↗
PubMed1979

Prenatal diagnosis of thrombocytopenia with absent radii.

Six pregnancies at risk for thrombocytopenia and absent radii (TAR) have been studied between 16 and 20 menstrual weeks utilizing fetal radiography. Two affected and four unaffected fetuses have been correctly identified. Fetal radiography can provide reliable prenatal diagnosis in pregnancies at risk for TAR.

Abortion, Induced↗
PubMed1978

Cervical cytology. Increased sensitivity with a second cervical smear.

Two consecutive Papanicolaou smears were obtained in 3524 patients during a single clinic visit. The first smear consisted of a combined cervical scrape and vaginal pool sample (Fast smear) while the second smear contained only a cervical scrape. Of the 93 patients with abnormal cytology, 71 (76%) patients were identified by the first smear and 74 (80%) by the second smear. The interpretation of the two smears correlated in 51 patients (54.8%). Of the remaining 42 patients, the cytologic findings were more advanced in the second smear in 19 cases, and in 23 cases the reverse was true. There were 19 instances in which the cytologic findings were suspicious or positive. In 8 (42.1%) of these 19, one of the two smears contained either negative (7) or atypical (1) cytologic findings. The histologic diagnosis corresponded to the more advanced cytologic findings in all cases. The addition of the second cervical smear increased the detection rate of suspicious of positive cytology by 26.3%.

Biopsy↗
PubMed1978

Radioimmunoassay of alpha-fetoprotein, with special reference to iodination and purification techniques.

We report a relatively simple and convenient method for iodinating human alpha-fetoprotein and for purifying the 125I-labeled material. The label is incorporated into human alpha-fetoprotein enzymatically by use of lactoperoxidase. Before each assay the labeled material is purified over two successive short columns: Sepharcryl S-200 Superfine and cellulose. This procedure removes both free iodine and "damaged" fetoprotein. With the purified material we developed a sensitive and reliable radioimmunoassay for alpha-fetoprotein in serum and amniotic fluid.

Amniotic Fluid↗
PubMed1975

Abortifacient effects of prostaglandin E2 in the pigtailed macaque (Macaca nemestrina).

15(S)15-methyl-prostaglandin E2 was evaluated for abortifacient effects at various stages of pregnancy in five Macaca nemestrina. Despite its reported effectiveness in inducing abortions in human beings, it was concluded that this compound is not appropriate for collecting fetal material of known gestational age for morphologic and histologic examinations.

Abortion, Induced↗
PubMedDate not supplied

Evaluation of housekeeping genes in placental comparative expression studies.

Preeclampsia and diabetes are complications of pregnancy that contribute to maternal and perinatal mortality worldwide. Results emerging from molecular studies of placentae may elucidate etiologically important genomic alterations. Appropriate application of real time reverse transcription (RT) PCR in comparative gene expression studies requires endogenous housekeeping genes to normalize between sample variations. Ideal housekeeping genes must have stable tissue expression, but few have been specifically studied in the placenta. We sought to identify candidate control genes by analyzing seven functionally distinct housekeeping genes (B2M, GAPDH, HMBS, HPRT, SDHA, TBP, YWHAZ) for their expression stability and level in the placenta. mRNA isolated from 20 placentae was analyzed for gene expression using RT-PCR. Expression stability (M) was assessed using normalization strategies previously used for other tissues. TBP and SDHA were the most stable, with an average expression stability of M = 0.43, followed by YWHAZ (M = 0.44) > HPRT (M = 0.53) > HMBS (M = 0.57) > GAPDH (M = 0.61) > B2M (M = 0.69). The genes tested ranged in abundance, with an approximately 300-fold increase from the lowest (HMBS) to the highest (B2M). By using TBP, SDHA and YWHAZ, with greater expression stability than those housekeeping genes commonly used in placenta studies, gene expression profile comparisons will have more sensitivity and specificity.

Adult↗