Search PubMedSearch

Biomedical subjects

R R Lenke

Publications and source records attributed to R R Lenke.

At least 19 recordsLinked to original sources

Rapid fetal lung maturity testing: commercial versus NBD-phosphatidylcholine assay.

We compared the TDx Fetal Lung Maturity test and the fluorescence polarization method using 1-palmitoyl-2(6-[(7-nitro-2,1,3-benzoxadiazol-4- yl)amino]caproyl)phosphatidylcholine (NBD-phosphatidylcholine). Using 76 paired human amniotic fluid samples, the fluorescence polarization values of the two methods were found to have a strong nonlinear correlation (r2 = 0.946). Both assays can be completed in less than 1 hour, have excellent precision (between-day variation less than 2%), and indicate the amount of surfactant phospholipid relative to albumin. The FLM assay is calibrated with surfactant/albumin standards; therefore, the reported results (in mg/g) correlate inversely with polarization of NBD-phosphatidylcholine. Strong correlations were seen for both assays with the lecithin-sphingomyelin ratio and phosphatidylglycerol. The correlations indicate that the recommended reference range for FLM will have more false predictions of immaturity than the NBD-phosphatidylcholine assay.

Albumins

Comparison of the accuracy of glucose reflectance meters in pregnant insulin-dependent diabetics.

Home monitoring of blood glucose by reflectance meters has been shown to be accurate in the nonpregnant diabetic and is currently used for outpatient glucose control in the pregnant diabetic as well. Beckman ASTRA glucose results from samples collected into sodium fluoride were used as the standard for this study. Comparisons were then made to four glucose reflectance meters: Accu-Check II, One Touch, DiaScan S, and ExacTech. Although the reflectance meters appeared to be useful for assessing blood glucose trends in the pregnant diabetic, the results obtained from these meters would be unacceptable in the laboratory setting. Unfortunately, because of the erratic combination of proportional and constant bias, correction factors are not easily ascertained. Laboratories and physicians should reconsider the use of these reflectance meters for inpatient evaluation and general population screening of pregnant women.

Blood Glucose Self-Monitoring

Prenatal diagnosis of autosomal dominant microcephaly and postnatal evaluation with magnetic resonance imaging.

A case of fetal autosomal dominant microcephaly was prenatally diagnosed with ultrasonography in a woman with previously undiagnosed microcephaly. At the time of initial ultrasonographic assessment, the mother was identified to have a markedly small cranium, consistent with maternal microcephaly. The ultrasonographic examination showed the fetal head size to be four standard deviations below the mean for gestational age. Gestational dating from the other biometric parameters and from the last menstrual period was consistent with 31 weeks' gestation. Neurosonographic evaluation of the fetus revealed no obvious structural abnormalities. Serial ultrasonographic examinations at 35 and 38 weeks' gestation showed no changes in the fetal head size. A 2.64 kg male fetus was delivered at term. Neonatal assessment showed the fetal head circumference to be less than the second percentile for gestational age. Neurologic assessment of the neonate with magnetic resonance imaging showed abnormal development of the brain, with small cerebellar and cerebral hemispheres, and pachygyria. These images are compared with the magnetic resonance images of the mother. Our findings of maternal and fetal microcephaly are consistent with autosomal dominant microcephaly. To our knowledge, this is the first report of the prenatal diagnosis of autosomal dominant microcephaly.

Adult

Ultrasonographic assessment of intestinal damage in fetuses with gastroschisis: is it of clinical value?

In cases of gastroschisis detected prenatally it has been proposed that ultrasonographic criteria may play an important role in the decision for early delivery. We evaluated five cases of gastroschisis diagnosed before birth and found a correlation between prenatally detected small bowel dilatation and severe intestinal damage. However, from the limited data available these in utero measurements seem to be ineffective as indicators for delivery intervention (1) because not all fetuses with bowel dilatation have postnatal evidence of intestinal damage, (2) because some infants with intestinal damage and a poor postnatal outcome may show no in utero evidence of bowel dilatation, (3) because initial bowel dilatation may occur before a gestational age when lung maturity is achieved, and (4) because, in those cases in which bowel dilatation did correlate with intestinal damage, the bowel was already beyond the point of salvage and the infant required bowel resection.

Abdominal Muscles

Agnathia malformation complex associated with a cystic distention of the oral cavity and hydranencepahly.

A fetus with a severe variant of the agnathia malformation complex (AMC) was delivered following prenatal diagnostic evaluation with ultrasonography. The constellation of anomalies that accompanied the agnathia included holoprosencephaly, hydranencephaly, situs inversus, and polysplenia. Recently, several authors have reported the association between the agnathia, holoprosencephaly, and situs inversus. We present evidence which suggests that, when hydranencephaly is also present, this may represent the most severe variant of the AMC. Our case is presented, the literature is reviewed, and a hypothesis regarding the embryopathologic mechanism is discussed.

Abnormalities, Multiple

In utero diagnosis of benign fetal macrocephaly.

Benign familial macrocephaly is an autosomal dominant disorder associated with a large absolute circumference of the head. In this disorder serial growth demonstrates a proportional rather than an excessive rate of growth. To date, we are not aware of any published case reports that confirm the diagnosis prenatally. We report a case of benign familial macrocephaly diagnosed in utero by ultrasonographic evaluation. This case report points out the necessity of combining appropriate family history and physical examination in cases of prenatally detected anomalies.

Adult

Elevated maternal serum alpha-fetoprotein values. How low is high?

Most maternal serum alpha-fetoprotein (MSAFP) screening programs are set up with the goal of prenatal detection of fetal neural tube defects. It is also commonly accepted that MSAFP testing yields many false-positive results. Screening programs commonly utilize schemata that identify abnormal levels of MSAFP as greater than 2.5 multiples of the median (MOM) and also recommend two abnormal values before initiating ultrasound evaluation. Our pilot program evaluating obstetric outcomes found that 21 of the 29 women with elevated MSAFP values (greater than 2.0 MOM) eventually developed significant pregnancy management changes or complications of pregnancy. Thus, we believe that the use of MSAFP screening solely for the purpose of detecting fetal neural tube defects is inconsequential relative to its usefulness in detecting other pregnancy abnormalities. We also believe that ultrasound evaluation should be accomplished after the first abnormal value and that the cutoff of 2.5 MOM should be lowered to at least 2.0.

Adult